Body-focused repetitive behaviors (BFRBs) are common but under-recognized mental disorders. The present study aimed to examine the efficacy of a video presentation of self-help techniques for BFRBs compared to a web-based intervention containing psychoeducation and comprehensive self-help treatment information on BFRBs to reduce symptomatology as well as the same videos as in the first condition.
Methods
A total of 217 participants with BFRBs were randomly assigned to (1) a video condition conveying the established self-help techniques habit reversal training (HRT), decoupling (DC), and decoupling in sensu (DC-is) to reduce BFRBs, (2) a website condition that offered psychoeducational information and treatment material, including the videos from the first treatment condition, or (3) a waitlist control (WLC) condition. A six-week post assessment was conducted. The Generic Body-Focused Repetitive Behavior Scale 45 (GBS-45) served as the primary outcome.
Results
The self-help video condition showed greater improvement in GBS-45 subscales for nail biting in comparison to the self-help website and WLC conditions. For other BFRBs (e.g., joint cracking, trichophagia), the impairment subscale showed significant results in post hoc analyses in favor of the two treatment conditions. Subjective ratings of the techniques were satisfactory and comparable across treatment groups, with slightly higher ratings in favor of the video condition.
Conclusions
The video condition showed better improvement than the control condition on nail biting and other BFRBs. Superior results in the self-help website condition compared to the WLC were shown only for the group of “other” BFRBs (i.e., not trichotillomania, nail biting, dermatillomania, lip/cheek biting). We speculate this might be because users were overwhelmed by the many different approaches described without clear guidelines for how to implement them in daily life. In light of a prior study, we assume that a manualized version of the self-help techniques is superior to the video delivery and recommend that the self-help videos should be used as a complement to a manualized version. Future research should address long-term effects of self-help interventions for BFRBs.
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Introduction
Body-focused repetitive behaviors (BFRBs) are excessively repeated self-grooming behaviors that manifest in the repetitive pulling, picking, or scratching of skin, nails, hair, or lips. BFRB conditions include dermatillomania (skin picking), trichotillomania (hair pulling), onychophagia (nail biting), and lip/cheek biting (cavitadaxia). Prevalence rates vary from 5 to 24% if physical damage and psychological distress are used as mandatory diagnostic criteria, and up to 90–97.1% if subclinical manifestations are included (Houghton et al., 2018; Moritz et al., 2023c; Solley & Turner, 2018).
Cognitive-behavioral interventions are currently considered the treatment of choice (Lee et al., 2019; The TLC Foundation for BFRBs, 2016). These have been recently enhanced with a variety of methods, including dialectical behavior therapy (Keuthen et al., 2011), acceptance and commitment therapy (Lee et al., 2020), and comprehensive behavior therapy (Carlson et al., 2021). Habit reversal training (HRT) for BFRBs (Azrin & Nunn, 1973) is currently considered the best established psychotherapeutic treatment for BFRB with the strongest evidence (Farhat et al., 2020; Lee et al., 2019; Skurya et al., 2020). Apart from awareness training, another core element of HRT is competing response training (CRT), in which individuals learn to replace the dysfunctional behavior with an incompatible posture.
A large treatment and research gap exists currently, with only a few affected individuals receiving evidence-based treatment (Grant et al., 2021; Houghton et al., 2018; Sampaio & Grant, 2018). To address the urgent need for evidence-based treatment, online-based self-help is increasingly seen as an important (bridging) treatment option (Lee et al., 2019). Our research group has developed several online-based self-help techniques to reduce BFRBs (for more detailed information, see “Intervention” section): self-help habit reversal training (usually conveyed by a therapist; Moritz et al., 2012), decoupling (DC; Moritz et al., 2011; Moritz & Rufer, 2011), and decoupling in sensu (DC-is; Moritz et al., 2012). These self-help techniques have been evaluated positively in several studies (e.g., Lee et al., 2019; Moritz et al., 2020a, 2020b, 2021, 2023a, 2023b; Schmotz et al., 2023) but independent replications are needed. Randomized controlled trials showed the effectiveness of DC relative to a waitlist control (WLC) group, particularly for onychophagia and trichotillomania (Moritz et al., 2011; Moritz & Rufer, 2011; Weidt et al., 2015). HRT, however, seems to be superior to DC for dermatillomania (Moritz et al., 2012). For DC-is, evidence for its efficacy has been obtained in controlled (e.g., Moritz et al., 2021, 2023a, 2023b; Schmotz et al., 2023) as well as single case trials (Moritz et al., 2020a, 2020b, 2022), but the data here are less solid compared to the other methods. Simultaneous application of the self-help techniques seems to augment the effects, especially when applying DC first (Moritz, et al., 2023a). Nevertheless, no strong conclusions can yet be drawn, and further research is needed to investigate the effectiveness of self-help techniques and their mechanisms of action. Moreover, independent replications for the DC and DC-is techniques are needed as well as more trials with an active control condition and studies on the underlying processes.
How self-help interventions are applied and delivered influences their effectiveness, presumably depending on the structure and intensity of the guidance (Baumeister et al., 2014; Karyotaki et al., 2021; Salazar de Pablo et al., 2023). Research on obsessive-compulsive disorder (OCD), for example, shows that with more frequent guidance, web-based therapy effects are enhanced (Hoppen et al., 2021; Lenhard et al., 2017; Pearcy et al., 2016). In addition, the extent of the content influences effectiveness. A study by Moritz et al. (2016) showed superiority of the full version of a self-help manual compared to a shorter self-help manual adapted to the individual problems of OCD patients.
The present study aimed to evaluate the effectiveness of a (1) a directed and focused video presentation of self-help techniques (HRT, DC, and DC-is) for BFRBs (video condition), (2) a web-based intervention (www.free-from-bfrb.org) containing psychoeducation and comprehensive self-help treatment information on BFRBs, including the self-help videos in the other intervention condition (website condition), and a (3)WLC condition. Thus, participants in both intervention conditions were given access to the video presentation of self-help techniques for BFRBs. The two intervention conditions differed in how the techniques were embedded in the context: the self-help videos on the techniques were either provided along with a variety of other disorder-specific information (website condition) or were provided with no other information (video condition).
Evaluations of web-based interventions suggest that comprehensive psychoeducational web-based interventions have a positive impact on symptoms of mental disorders in general and on psychological well-being, quality of life, and social and emotional functioning (Boumparis et al., 2022; Musiat et al., 2022; Zahiri Esfahani et al., 2020). However, informational and interventional websites also face problems according to some studies, for example high attrition, and frequent violation of user expectations (Farvolden et al., 2005; Musiat et al., 2014; Schneider et al., 2014). These findings should be considered with caution due to the heterogeneity of the aforementioned web-based interventions as well as the lack of contemporary reviews. Web-based interventions still require further research to elucidate the mechanisms of action and to be able to make reliable statements about their effectiveness.
We hypothesized that the multi-modal therapeutic information provided on the website, which included the self-help techniques delivered in the video condition, would lead to greater symptom reduction than the more focused video approach and that both interventions would be superior to the control condition.
Methods
Recruitment and Procedure
The study was advertised as an unguided treatment study for people with BFRBs. Participants were recruited on our research group’s website (www.uke.de/decoupling) and through self-help forums on social media (e.g., Facebook). Participants were also recruited via the German Society for Obsessive Compulsive Disorders (DGZ), which is a German nonprofit organization dedicated to helping people with obsessive-compulsive and related disorders. The study was registered in the German Clinical Trials Register (DRKS00028830) and approved by the local ethics committee for psychologists at the University Hospital of Hamburg-Eppendorf in Germany (LPEK-0441d). According to the guidelines of the European General Data Protection Regulation (GDPR), no IP addresses were stored. Participants were instructed to create email addresses that did not reveal their names so that their participation remained anonymous. There was no financial compensation for study participation.
Assessment
The study was conducted online using Qualtrics®. After an introduction to the aims and rationale of the study, electronic consent was requested as a mandatory precondition for participation. Subsequent questions included participants’ sociodemographic background and medical history (e.g., previous experience with psychotherapy, current treatment status, previous psychiatric diagnoses). At the end of the baseline assessment, participants were asked whether they had answered the questions truthfully (mandatory inclusion criterion).
Treatment Allocation
Concealed allocation was ensured by automatically assigning participants to one of the two intervention groups (website or videos) or to the WLC condition (random assignment 1:1:1). The two intervention groups received an email with a link to the website that corresponded to their condition. After six weeks, participants were automatically invited via email to complete the post survey, and they received up to three reminders to respond to the post assessment. The same questionnaires were presented as in the initial baseline survey. To match baseline and post survey data, participants were asked to re-enter their email addresses. Respondents were also asked whether their answers were truthful (inclusion criterion as in the baseline survey).
Participants
In total, 847 participants accessed the survey. Of these, only 304 viewed the first page of the survey; 55 did not complete the questionnaire, 10 did not agree to informed consent, and 22 were excluded due to violation of inclusion or exclusion criteria (n = 13 had a history of schizophrenia or bipolar disorder, n = 3 indicated acute suicidality as measured by a score of 3 on the Patient Health Questionnaire rating for suicidal ideation, n = 2 did not have a valid email address, n = 2 were under 18 years old, n = 2 did not respond truthfully). The final sample comprised 217 participants (for the CONSORT flowchart, see Fig. 1).
Fig. 1
CONSORT flowchart for the study. CC = complete cases analysis, participants with complete pre-post data; PP = per-protocol analysis, participants with complete pre-post data who had viewed the website or the videos at least once
×
Intervention
Self-Help Videos
The video intervention group received access to a website containing videos that explain and sequentially demonstrate the three self-help techniques habit reversal training (HRT), decoupling (DC), and decoupling in sensu (DC-is). The original videos were displayed in German; a similar version can be found at https://www.free-from-bfrb.org/videos/ (note that the participants in the study did not have access to the www.free-from-bfrb.org website). The introductory part recommends an observational phase to sensitize users to their triggers and contextual antecedents of BFRBs, which they are asked to record in a table. The total length of the first (introductory) video is 18:31 min.
Self-help HRT involves responding to the urge to perform the dysfunctional behavior (e.g., to pick the skin) with a rigid posture (e.g., sitting on one’s hands), thus replacing and suppressing the dysfunctional behavior. It is recommended that users practice the opposing rigid posture in the situations where their dysfunctional behavior normally occurs (users were instructed to hold the posture for 1–3 min). Additionally, it is recommended that they set a smartphone timer as a reminder to practice the alternative behavior. In DC, in contrast, the BFRB is not suppressed but redirected. In the first phase of DC, the dysfunctional behavior is simulated. Immediately before the dysfunctional behavior is performed (e.g., the hand briefly touches the skin of the face in dermatillomania), the movement is redirected with tension and acceleration (e.g., toward the earlobe or away from the body). The video explicitly recommends practicing the DC technique at least three times a day (repeating it 10 times in a row each time) and in situations where the behavior usually occurs. Users are shown how to set a smartphone timer. DC-is is demonstrated last of the three techniques. It is similar to DC, but the first (approach) phase is performed only in the imagination. Just before the execution of the BFRB occurs in the imagination, the dynamic redirection takes place in reality through the execution of the actual new (benign) behavior. DC-is is intended to increase the generalization of BFRBs since individuals only imagine the dysfunctional behavior pattern and do not actually perform a specific movement, as they do in HRT and DC (Moritz et al., 2021; Schmotz et al., 2023).
The second video presents only self-help HRT (2:17 min), the third video explains the DC technique (6:08 min), and the fourth video demonstrates the DC-is technique (2:31 min).
Self-Help Website
The Free from BFRB website (website condition) includes comprehensive information about the three self-help techniques to reduce BFRB symptoms described above as well as a wide range of other information about BFRBs, such as the prevalence and the symptoms of the different conditions (for more information on the German version used in the present study, see https://www.tricks-gegen-ticks.de/; for the English version, see www.free-from-bfrb.org). The website is fully self-directed and a total of six menus are provided. The first menu conveys information about common BFRB conditions: core symptoms and treatment options, hair pulling (trichotillomania), nail biting (onychophagia), skin picking (dermatillomania), lip/cheek biting (cavitadaxia), and other BFRBs such as joint cracking, eating of hair (trichophagia), and skin biting (dermatophagia). The second menu offers a description of the three self-help techniques—HRT, DC, and DC-is—in text format. This text-based set of instructions for the self-help techniques is the foundation of the self-help videos accessed in the next menu. The third menu offers the video-based explanation of the three self-help techniques, with the same videos as in the video intervention group (who had no access to the website intervention). The purpose of the fourth menu, titled “helpful things,” is to present miscellaneous helpful strategies for symptom relief. Products which are deemed helpful for BFRBs in general are presented (e.g., sensory stimulation and fidget toys, beauty and care products, apps, online programs, and gadgets) as well as products that are considered only for specific BFRB conditions (e.g., the recommendation to those suffering from onychophagia to use a nail file and hand cream to prevent the rough patches or brittle nails that could foster the urge to bite nails). The fifth menu lists self-help books by affected individuals and professional advisors. The last menu contains further links to reports about BFRBs in the media, podcasts, blogs, and self-help groups. In light of the present research findings (Moritz et al., 2023a, 2023b), the website has now been updated with the advice to apply the self-help technique DC first and then to gradually combine all three of the self-help techniques (HRT, DC, DC-is). This suggested protocol was not implemented at the time of the data collection, so the participants did not receive any recommendations or instructions on how to apply the techniques. Apart from these guidelines, the website is the same as the version used in the study.
Assessment
Primary Outcome
The Generic Body-Focused Repetitive Behavior Scale 45 (GBS-45; Schmotz et al., 2023) assesses the severity of various BFRB conditions (trichotillomania, dermatillomania, onychophagia, cavitadaxia, and others), with 9 items for each condition. In addition to the total score, two subscales (symptom severity and impairment) are computed. The symptom severity subscale represents the sum of items 1, 2, and 4 and the mean of items 3 and 5. The impairment subscale consisted of the sum of items 6–9 (Moritz et al., 2021). Items are rated on a 5-point Likert scale (0–4 with 4 indicating full endorsement). The period under consideration is the previous seven days.
Secondary Outcomes
Self-rated severity of depression was measured by the German version of the Patient Health Questionnaire (PHQ-9; Gilbody et al., 2007; Kroenke et al., 2001) on a 4-point scale (from 0 = not at all to 3 = almost every day). The PHQ-9 consists of nine items and shows satisfactory internal consistency and test-retest reliability as well as criterion and construct validity (Gräfe et al., 2004; Kroenke et al., 2001; Kroenke & Spitzer, 2002; Martin et al., 2006). Participants who indicated acute suicidality, as measured by a score of 3 on suicidal ideation item 9 (Over the last 2 weeks, how often have you been bothered by thoughts that you would be better off dead, or of hurting yourself in some way?—(1) not at all, (2) several days, (3) more than half of the days, (4) nearly every day) were excluded from the study and were immediate given 24/7 emergency numbers and access to emergency chats to get help.
The global item of the World Health Organization Quality of Life-BREF (WHOQOL-BREF; Skevington et al., 2004) measured quality of life using a 5-point Likert scale (from 1 = very poor to 5 = very good).
To measure satisfaction with the intervention, the Client Satisfaction Questionnaire (CSQ-8; Attkisson & Zwick, 1982; see online appendix Table 3) was used, adapted for online assessment. The questionnaire consists of eight items and has good internal consistency (Cronbach’s α = 0.87 to 0.93; Schmidt et al., 1989) and criterion and construct validity (Kriz et al., 2008). In addition, satisfaction with the treatment technique was measured with a self-developed 9-item questionnaire (e.g., Schmotz et al., 2023; see online appendix Table 4), which was rated on a 4-point Likert scale (from 1 = strongly disagree to 4 = strongly agree). Participants could indicate what they liked or disliked about the intervention in response to open-ended questions.
As a moderator variable, a subset of items from the University of Rhode Island Change Assessment (URICA) (Greenstein et al., 1999) was used at baseline, assessing willingness to change on a 5-point Likert scale (from 1 to 5 with 5 indicating full endorsement).
Strategy of Data Analysis
A power analysis using G*Power (Erdfelder et al., 1996) to calculate sample sizes showed that at least 70 participants in each group would be sufficient to detect a medium effect size (d = 0.5).
All statistical analyses were performed using IBM SPSS® Statistics version 27. Intention-to-treat (ITT) analyses were performed on the data from all participants using the available baseline data; missing values were estimated using the expectation maximization (EM) algorithm (Dempster et al., 1977). Additionally, complete cases (CC; participants with complete pre-post data) and per-protocol (PP; participants with complete pre-post data who had viewed the website or the videos at least once) analyses were performed. For the main results, mixed ANOVAs were conducted, with condition (videos, website, waitlist) as the between-subject and time (pre, post) as the within-subject factors. Significant interaction effects were examined by least significant difference (LSD) post hoc tests. The aforementioned analyses (ITT, CC, PP) were performed for several parameters: the GBS-45 total score, the GBS-45 subscales severity and impairment (separately) for each of the four BFRB subtypes assessed by the GBS-45, depressive symptoms, and quality of life. Moderation analyses were performed using the SPSS® macro PROCESS® (Hayes, 2013) to identify subgroups of participants with divergent outcomes to explore factors facilitating or obstructing outcomes. An alpha error level of 5% was set (two-sided). For effect sizes, partial eta square (ηp2) and Cohen’s d were calculated (Cohen, 1992).
Results
Baseline Characteristics
The final sample consisted of 217 participants. A total of 74 participants were allocated to the self-help website, while 73 were allocated to the video condition and 70 to the WLC condition (see Fig. 1). Most participants were female and in their early 30s, and the groups did not differ significantly in either sociodemographic or psychopathological variables at baseline. Treatment status (e.g., new psychotherapy/medication initiated, change of dosage, etc.) remained stable for most individuals (90.3%) from baseline to post assessment, with no differences across groups (χ2 (2) = 1.06, p = .589). The prevalence of diagnoses was based on the question “Have you ever received one or more of the following diagnoses?” and thus relied on self-report data. Depression was reported in about a quarter of the cases (25.7–31.5% across groups), and obsessive-compulsive disorder was less common (1.4–7.1% across groups). Regarding BFRB types, dermatillomania (77.1–79.5% across groups) and onychophagia (35.6–47.3% across groups) were most prevalent, followed by cavitadaxia (17.6–28.8% across groups), trichotillomania (12.3–16.2% across groups), and other BFRB conditions (9.5–11.4% across groups). More than half of the participants had never received a diagnosis for a psychiatric disorder (50.7–55.7% across groups; see Table 1).
Table 1
Baseline characteristics of the sample. Means, standard deviations and frequencies
WLC = waitlist control group, GBS-45 = Generic Body-Focused Repetitive Behavior Scale 45, WHOQOL-BREF = World Health Organization Quality of Life-BREF, PHQ-9 = Self-Assessment Questionnaire for Depressive Symptoms
Adherence and Efficacy
Completion at post assessment was 71.4% (68.9% in the website condition, 75.3% in the video condition, and 70.0% in the WLC condition), with no differences across groups (χ2 (2) = 0.85, p = .655). Most participants in the experimental conditions reported having viewed the website or the videos at least once (78.3%, χ2 (1) = 0.95, p = .330), while 52.9% performed the exercises at least once in the intervention period, again with no group difference (χ2 (1) = 1.72, p = .190), and 20.7% performed them weekly (χ2 (1) = 0.08, p = .779).
Table 2 shows main effects of time first, irrespective of group allocation. Significant main effects of time were found in all analyses (ITT, CC, and PP) with respect to the GBS-45 total score (medium-to-large effect sizes), the symptom severity subscale (medium-to-large effect sizes), the severity subscale for dermatillomania (medium-to-large effect size), the severity subscale for onychophagia (large effect size), and the impairment subscale for dermatillomania (large effect size). There was also a significant main effect for the impairment subscale for onychophagia in both the ITT (p < .001, ηp2 = 0.134) and PP (p = .031, ηp2 = 0.100) analyses, and the CC analysis showed a statistical trend (p = .075, ηp2 = 0.061) for improvement. Additionally, the symptom severity subscale for other BFRBs and the impairment subscale for trichotillomania and cavitadaxia showed significant and large main effects of time in ITT analyses. Results did not achieve a significant main effect of time for the quality of life, depressive symptoms, or GBS severity subscales for trichotillomania and cavitadaxia nor for the GBS total impairment subscale or the impairment subscale for other BFRBs (see Table 2). To conclude, individuals in the experimental conditions showed significant within-group improvement for most parameters.
Table 2
Intention-to-treat, complete cases, and per-protocol analyses of change in symptom severity, quality of life, and depressive symptoms over time
Intention-to-treat
(ITT)
(W: n = 74;
V: n = 73;
WLC: n = 70)
Complete Cases
(CC)
(W: n = 51;
V: n = 55;
WLC: n = 49)
Per-Protocol
(PP)
(W: n = 42;
V: n = 41;
WLC: n = 49)
T = Time; I = Interaction;
[Differences between W, V, and WLC in square brackets]
GBS-45 total score
T: F(1,214) = 14.02, p < .001, ηp2 = 0.061
I: F(2,214) = 0.26, p = .770, ηp2 = 0.002
[V = W: p = .471;
V = WLC: p = .689;
WLC = W: p = .755]
T: F(1,152) = 10.75,
p = .001, ηp2 = 0.066
I: F(2,152) = 0.72,
p = .491, ηp2 = 0.009
[V = W: p = .679;
V = WLC: p = .238;
W = WLC: p = .449]
T: F(1,129) = 11.78, p < .001, ηp2 = 0.084
I: F(2,129) = 1.09, p = .338, ηp2 = 0.017
[V = W: p = .658;
V = WLC: p = .329;
W = WLC: p = .658]
GBS-45 severity
T: F(1,214) = 28.04, p < .001, ηp2 = 0.116
I: F(2,214) = 0.65, p = .524, ηp2 = 0.006
[V = W: p = .639;
V = WLC: p = .112;
W = WLC: p = .276]
T: F(1,152) = 18.64,
p < .001, ηp2 = 0.109
I: F(2,152) = 1.02,
p = .362, ηp2 = 0.013
[W = V: p = .971;
V = WLC: p = .217;
W = WLC: p = .212]
T: F(1,129) = 18.91, p < .001, ηp2 = 0.128
I: F(2,129) = 1.47, p = .233, ηp2 = 0.022
[V = W: p = .995;
V = WLC: p = .145;
W = WLC: p = .146]
GBS severity Dermatillomania
T: F(1,167) = 51.49, p < .001, ηp2 = 0.236
I: F(2,167) = 0.15, p = .858, ηp2 = 0.002
[W = V: p = .611;
WLC = V: p = .951;
W = WLC: p = .661]
T: F(1,113) = 29.34,
p < .001, ηp2 = 0.206
I: F(2,113) = 1.17,
p = .314, ηp2 = 0.020
[W = V: p = .365;
V = WLC: p = .501;
W = WLC: p = .131]
T: F(1,100) = 30.33, p < .001, ηp2 = 0.233
I: F(2,100) = 1.22, p = .300, ηp2 = 0.024
[W = V: p = .745;
V = WLC: p = .246;
W = WLC: p = .143]
GBS severity Onychophagia
T: F(1,87) = 26.14, p < .001, ηp2 = 0.231
I: F(2,87) = 6.76, p = .002, ηp2 = 0.135
[V > W: p = .008;
V > WLC: p < .001;
W = WLC: p = .313]
T: F(1,51) = 9.83,
p = .003, ηp2 = 0.162
I: F(2,51) = 8.38,
p < .001, ηp2 = 0.247
[V > W: p = .036;
V > WLC: p < 001;
W > WLC: p = .034]
T: F(1,45) = 36.20, p = .002, ηp2 = 0.198
I: F(2,45) = 26.68, p < .001, ηp2 = 0.267
[V ≥ W: p = .098;
V > WLC: p < .001;
W > WLC: p = .010]
GBS severity Trichotillomania
T: F(1,27) = 0.91, p = .350, ηp2 = 0.032
I: F(2,27) = 64.15, p = .027, ηp2 = 0.235
[V ≥ W: p = .054;
WLC = V: p = .511;
WLC > W: p = .011]
T: F(1,17) = 1.40,
p = .252, ηp2 = 0.076
I: F(2,17) = 1.64,
p = .224, ηp2 = 0.161
[V = W: p = .435;
WLC = V: p = .274;
WLC ≥ W: p = .088]
T: F(1,11) = 0.43, p = .528, ηp2 = 0.037
I: F(2,11) = 1.13, p = .357, ηp2 = 0.171
[V = W: p = .618;
WLC = V: p = .392;
WLC = W: p = .164]
GBS severity Cavitadaxia
T: F(1,39) = 0.23, p = .634, ηp2 = 0.006
I: F(2,39) = 1.81, p = .176, ηp2 = 0.085
[W = V: p = .496;
WLC = V: p = .384;
WLC ≥ W: p = .092]
T: F(1,27) = 1.77,
p = .194, ηp2 = 0.062
I: F(2,27) = 0.12,
p = .889, ηp2 = 0.009
[V = W: p = .640;
V = WLC: p = .946;
WLC = W: p = .680]
T: F(1,23) = 1.94, p = .178, ηp2 = 0.078
I: F(2,23) = 0.20, p = .817, ηp2 = 0.017
[V = W: p = .530;
V = WLC: p = .742;
WLC = W: p = .699]
GBS severity other BFRBs
T: F(1,17) = 6.64, p = .020, ηp2 = 0.281
I: F(2,17) = 1.88, p = .182, ηp2 = 0.181
[V = W: p = .463;
WLC = V: p = .396;
WLC = W: p = .117]
T: F(1,4) = 0.47,
p = .532, ηp2 = 0.104
I: F(2,4) = 2.11,
p = .237, ηp2 = 0.513
[V = W: p = .303;
V = WLC: p = .110;
W = WLC: p = .492]
T: F(1,4) = 0.47, p = .532, ηp2 = 0.104
I: F(2,4) = 2.11, p = .237, ηp2 = 0.513
[V = W: p = .303;
V = WLC: p = .110;
W = WLC: p = .492]
GBS impairment
T: F(1,212) = 0.32, p = .570, ηp2 = 0.002
I: F(2,212) = 1.27, p = .284, ηp2 = 0.012
[W = V: p = .336;
V = WLC: p = .384;
W ≥ WLC: p = .069]
T: F(1,152) = 1.75,
p = .189, ηp2 = 0.011
I: F(2,152) = 0.59,
p = .558, ηp2 = 0.008
[V = W: p = .343;
V = WLC: p = .366;
WLC = W: p = .974]
T: F(1,129) = 2.51, p = .115, ηp2 = 0.019
I: F(2,129) = 0.75, p = .475, ηp2 = 0.011
[V = W: p = .335;
V = WLC: p = .254;
W = WLC: p = .886]
GBS impairment Dermatillomania
T: F(1,167) = 2.23, p < .001, ηp2 = 0.113
I: F(2,167) = 0.48, p = .618, ηp2 = 0.006
[V = W: p = .383;
V = WLC: p = .414;
WLC = W: p = .968]
T: F(1,113) = 11.15,
p = .001, ηp2 = 0.090
I: F(2,113) = 1.03,
p = .360, ηp2 = 0.018
[V = W: p = .536;
V = WLC: p = .154;
W = WLC: p = .422]
T: F(1,100) = 8.98, p = .003, ηp2 = 0.082
I: F(2,100) = 0.75, p = .474, ηp2 = 0.015
[V = W: p = .671;
V = WLC: p = .229;
W = WLC: p = .445]
GBS impairment Onychophagia
T: F(1,84) = 13.03, p < .001, ηp2 = 0.134
I: F(2,84) = 6.08, p = .003, ηp2 = 0.126
[V > W: p = .001;
V > WLC: p = .006;
WLC = W: p = .636]
T: F(1,51) = 3.31,
p = .075, ηp2 = 0.061
I: F(2,51) = 3.26,
p = .047, ηp2 = 0.113
[V > W: p = .026;
V > WLC: p = .037;
WLC = W: p = 1.000]
T: F(1,45) = 4.99, p = .031, ηp2 = 0.100
I: F(2,45) = 3.30, p = .046, ηp2 = 0.128
[V > W: p = .043;
V > WLC: p = .022;
WLC = W: p = .741]
GBS impairment Trichotillomania
T: F(1,27) = 5.36, p = .028, ηp2 = 0.166
I: F(2,27) = 1.65, p = .211, ηp2 = 0.109
[V ≥ W: p = .095;
V = WLC: p = .646;
WLC = W: p = .228]
T: F(1,17) = 0.91,
p = .353, ηp2 = 0.051
I: F(2,17) = 1.71,
p = .211, ηp2 = 0.167
[V = W: p = .199;
WLC = V: p = .563;
WLC ≥ W: p = .097]
T: F(1,11) = 0.22, p = .648, ηp2 = 0.020
I: F(2,11) = 1.45, p = .277, ηp2 = 0.208
[V = W: p = .194;
WLC = V: p = .960;
WLC = W: p = .156]
GBS impairment Cavitadaxia
T: F(1,39) = 7.02, p = .012, ηp2 = 0.153
I: F(2,39) = 1.56, p = .223, ηp2 = 0.074
[W = V: p = .236;
WLC = V: p = .098;
WLC = W: p = .717]
T: F(1,27) = 0.07,
p = .787, ηp2 = 0.003
I: F(2,27) = 0.08,
p = .922, ηp2 = 0.006
[W = V: p = .691;
WLC = V: p = .867;
W = WLC: p = .789]
T: F(1,23) = 0.03, p = .856, ηp2 = 0.001
I: F(2,23) = 0.05, p = .956, ηp2 = 0.004
[W = V: p = .777;
V = WLC: p = .955;
W = WLC: p = .802]
GBS impairment other BFRBs
T: F(1,11) = 0.86, p = .375, ηp2 = 0.072
I: F(2,11) = 1.73, p = .223, ηp2 = 0.239
[W = V: p = .356;
V > WLC: p = .043;
W > WLC: p = .005]
T: F(1,4) = 0.13,
p = .914, ηp2 = 0.003
I: F(2,4) = 1.11,
p = .415, ηp2 = 0.356
[V = W: p = .901;
V = WLC: p = .260;
W = WLC: p = .308]
T: F(1,4) = 0.01, p = .914, ηp2 = 0.003
I: F(2,4) = 1.11, p = .415, ηp2 = 0.356
[V = W: p = .901;
V = WLC: p = .260;
W = WLC: p = .308]
Quality of life (WHOQOL-BREF)
T: F(1,214) = 2.24, p = .136, ηp2 = 0.010
I: F(2,214) = 0.18, p = .835, ηp2 = 0.002
T: F(1,151) = 0.81,
p = .370, ηp2 = 0.005
I: F(2,151) = 0.04,
p = .958, ηp2 = 0.001
T: F(1,128) = 1.23, p = .269, ηp2 = 0.010
I: F(2,128) = 0.10, p = .906, ηp2 = 0.002
Depressive symptoms
(PHQ-9)
T: F(1,214) = 2.05, p = .154, ηp2 = 0.009
I: F(2,214) = 0.42, p = .660, ηp2 = 0.004
T: F(1,152) = 0.41,
p = .525, ηp2 = 0.003
I: F(2,152) = 0.18,
p = .834, ηp2 = 0.002
T: F(1,129) = 1.95, p = .165, ηp2 = 0.015
I: F(2,129) = 0.01, p = .992, ηp2 < 0.001
W = website condition, V = video condition, WLC = waitlist control group, ITT = intention-to-treat analysis, all cases considered, missing values were estimated with expectation-maximization method (EM), CC = complete cases analysis, participants with complete pre-post data, PP = per-protocol analysis, paritcipants with complete pre-post data who had viewed the website or videos at least once, GBS-45 = Generic Body-Focused Repetitive Behavior Scale 45, WHOQOL-BREF = World Health Organization Quality of Life-BREF, PHQ-9 = Self-Assessment Questionnaire for Depressive Symptoms
Interaction effects between time and group (see Table 2) were significant for the ITT, CC, and PP analyses for onychophagia for both the severity and the impairment subscales (medium-to-large and large effect sizes). Post hoc analyses showed significant superiority of the video condition compared to both the website and the WLC condition. Furthermore, post hoc analyses were significant for the impairment subscale for “other BFRBs” in favor of the two intervention conditions compared to the WLC (videos > WLC: p = .043, website > WLC: p = .005). However, this result should be interpreted with caution as the interaction effect of the omnibus test did not reach significance (p = .223, ηp2 = 0.239). There were no significant results for the other GBS scales regarding interaction effects.
For the trichotillomania severity subscale, the video condition was superior to the website condition at a statistical trend level (p = .054). Unexpectedly, the website condition was significantly inferior to the WLC condition (p = .011).
Moderation
Moderator analyses were performed to identify moderators for group-related improvements on the GBS-45 total score. The two treatment conditions were superior to the WLC condition for individuals who indicated more fatigue and lack of energy in the PHQ-9 (videos vs. WLC: coefficient: 6.251, SE: 1.894, t = 3.300, p < .001, lower limit confidence interval (LLCI): 2.492, upper limit confidence interval (ULCI): 10.010; website vs. WLC: coefficient: 5.456, SE: 1.787, t = 3.054, p = .003, LLCI: 1.909, ULCI: 9.003). Similar results emerged for the PHQ-9 total score, but only at a statistical trend level (videos vs. WLC: coefficient: 0.646, SE: 0.361, t = 1.793, p = .076, LLCI: − 0.069, ULCI: 1.362; website vs. WLC: coefficient: 0.617, SE: 0.340, t = 1.813, p = .073, LLCI: − 0.058, ULCI: 1.293). Individuals indicating more openness to psychological treatment (as measured by URICA item 8: “Psychological talk is boring. Why can’t you just forget your problems?” [inverse]) showed significantly greater improvement in BFRB symptoms in the video condition compared to the WLC condition (coefficient: − 9.607, SE: 3.454, t = − 2.781, p = .006, LLCI: − 16.460, ULCI: − 2.753).
Subjective Efficacy and Feasibility
The subjective ratings of participants in the intervention groups are presented in the online appendix in Table 3. Approximately half of the participants in each group indicated that the self-help treatment they received met their needs. More than three-quarters of the participants would recommend the self-help treatment to a friend with similar symptoms, and more than 80% rated the quality as good to excellent. No significant differences were found between groups, with mainly small to very small effect sizes.
Satisfactory to good acceptance and subjective effectiveness were found for both intervention conditions (see online appendix Table 4), also without significant differences between groups. Of the website group, 83.4% indicated that they had to force themselves to use the self-help, as did 73.1% of the video group. Furthermore, about one-fifth in the website condition (21.4%) and approximately one-third in the video condition (31.7%) reported having used the intervention on a regular basis. At least 90.2% of participants in the two intervention groups reported that the self-help was useful and appropriate for self-administration. Reduced BFRB symptoms due to the application of the self-help was reported by 46.3% in the video condition and 38.1% in the website condition.
Reliability of Measures
The test-retest reliabilities for the WLC (n = 70) on the GBS-45 (total score: r = .652, p < .001; severity subscale: r = .688, p < .001; impairment subscale: r = .618, p < .001) and PHQ-9 (r = .689, p < .001) were acceptable to satisfactory. However, test-retest reliability of the WHOQOL-BREF was poor (r = .536, p < .001).
Discussion
In the framework of a randomized controlled trial, the present study compared the effectiveness of (1) a directed and focused presentation of self-help techniques for BFRBs via video presentation (video condition), (2) a fully self-directed website containing psychoeducation and extensive treatment information on BFRBs (website condition), and (3) a waitlist control (WLC) condition.
Our expectation that the website condition would be superior to the video condition was largely not confirmed. Individuals in both the video and the website groups showed significant improvement on the GBS-45 total score, total severity subscale, and severity and impairment subscales for dermatillomania after the six-week period. Although individuals in the WLC condition showed significant within-group effects only on the severity subscale for dermatillomania, the experimental conditions showed no larger improvements for most parameters, with two notable exceptions. Nail biting (onychophagia) was the only condition where clear group differences over time were observed, but only for the video condition. For the “other BFRBs” condition, which included thumb sucking and joint cracking, the video and website conditions were superior to the WLC condition for the impairment subscale. However, the sample size was small, and these results should be interpreted with caution.
To our surprise, for the trichotillomania severity subscale, the video and the WLC condition were superior to the website condition at trend level and significance level, respectively. Moderation analyses indicated the superiority of both the intervention groups in reducing BFRB symptoms for individuals with more severe depressive symptoms compared to the WLC. Additionally, those with higher scores on openness to psychological treatment displayed a significantly greater improvement in BFRB symptoms in the video group compared to the WLC, emphasizing the role of motivation.
Although the two conditions did not significantly differ on subjective ratings, we would like to mention two numerical differences that may hint at an advantage of the videos over the website condition. First, 83.4% of the website group but only 73.1% of the video group indicated that they had to force themselves to use the self-help offered. In addition, about one-fifth of the website condition and about one-third of the video condition reported having used the intervention regularly.
While our results seem at odds with prior results on the efficacy of the combination of HRT and DC as well as DC-is (Moritz et al., 2021, 2023a, 2023b; Schmotz et al., 2023) with the exception of nail biting, the results tie in well with a recent randomized controlled trial (Moritz et al., 2023d) in which individuals who received a manualized form of the self-help concept (not investigated here) achieved significant symptom reduction compared to participants in the WLC condition, whereas participants who watched the videos showed only a statistical trend toward symptom reduction compared to the WLC group (for the severity subscale, the difference between the manual condition and the WLC remained significant at a medium effect size whereas significance was not reached for the video group). This and our present results suggest that a video may not be best method for conveying the self-help concepts.
The result that the website condition was not more effective than the WLC condition was unexpected and warrants further explanation, especially because the website condition fully incorporated the video condition. These findings may be reconciled with recent findings showing that web-based interventions without instructions or guidance may yield lower effectiveness and higher dropout rates while more directed web-based interventions are as effective as treatment as usual and may increase participant adherence (Musiat et al., 2022; Philippe et al., 2022; Zhao et al., 2017). Additionally, unguided web-based interventions may result in similar improvement compared to in-person therapy when supplemented with face-to-face contact as requested by the participants (Aspvall et al., 2021). According to a recent systematic review (Borghouts et al., 2021), participants using fully self-directed interventions (similar to the website condition in our study) experienced difficulty with engagement and sometimes neglected to use the intervention; they therefore expressed a preference for more structure, such as reminders or human contact.
In our study, guidance in the website condition was far lower compared to the video condition because, unlike in the video condition, this condition offered no explicit instructions or guidance on the use of the self-help techniques (this has since been changed; the website now contains a suggested protocol to guide users). The video condition was more explicit on how to perform the exercises and how often. The participants were also instructed on how to set up their smartphone for reminders. We speculate that participants in the website condition were overwhelmed by the information on the techniques and unsure how to implement the various recommendations and interventions (e.g., sequential or in parallel), thus reducing overall adherence. In line with this, Baker et al. (2021) suggest that less can be more; too many components/options in interventions can be problematic due to the possibility of negative interactions.
A number of limitations of the present study must be acknowledged. First, sampling bias cannot be excluded due to the partially unequal composition of the sample with respect to various demographic characteristics. More than 90% of the sample were women in their early 30s, and none of the respondents reported a diverse gender. Future studies should aim for a more balanced participation of all genders. Also, a more balanced inclusion of the various BFRB conditions should be sought. In the present sample, more individuals with dermatillomania (77.1–79.5% across groups) and onychophagia (35.6–47.3% across groups) participated compared to trichotillomania (12.3–16.2% across groups), which may have affected the results. However, there were no significant differences in these variables between the conditions, so this is an unlikely reason for the lack of between-group differences. Second, all data relied on self-assessment, so the effects of social desirability and other response biases (e.g., under-reporting due to shame) cannot be excluded. Future studies should implement a concurrent assessment of the self-report and expert-rated methods for assessing both BFRB diagnosis and the severity of BFRB symptomatology. Another limitation is that the six-week assessment period of the present study can only provide information on the short-term effects of the self-help programs. It cannot be determined whether there are “sleeper” (long-term) effects (for sleeper effects, see Moritz et al., 2014), so follow-up studies would be desirable. Furthermore, it would have been useful if we had asked users which self-help techniques (DC, DC-is, or HRT) they adopted in order to elucidate differential effects and to ask which menus of the website have been useful.
Future research should further investigate the set-up and structure of psychoeducational web-based interventions to identify features that have positive impacts on BFRB symptomatology as well as factors that likely induce detrimental effects. Websites such as Free from BFRB may be improved by providing help-seeking individuals with more structure through a suggested protocol so that individuals are not overwhelmed when confronted with the large amount of material and, as a result, do not know where to start or how to proceed. We assume that the challenge of reviewing and synthesizing the information on the website made it difficult for users to formulate a clear self-help treatment plan for themselves. Accordingly, a more focused delivery of self-help techniques with clear instructions regarding treatment goals and practical implementation via video—or, even better, via a manual (see Moritz et al., 2023d)—may lead to greater symptom reduction.
In our view, the presentation of self-help techniques for BFRBs in a manual remains the format of choice, but these results should be interpreted with caution until further research is completed. In line with previous research (but contrary to our initial hypothesis), the more structured and guided video intervention fared better in comparison to the more extensive but unstructured website condition, which may partly account for the lack of efficacy of the website condition. Overall, no consistent differences between conditions were obtained. While the video condition had significant effects on nail biting and other BFRBs, it was not superior to the WLC in terms of total effects. To conclude, the results of the present study corroborate prior research that the format and amount of structure in which self-help techniques are presented influence their effectiveness in reducing BFRB symptomatology.
Declarations
Conflict of Interest
Stella Schmotz and Steffen Moritz developed the self-help techniques as well as the evaluated videos and website. Therefore, bias cannot be completely excluded. Stella Schmotz, Erva Dilekoglu, Luca Hoyer, Anna Baumeister, and Steffen Moritz declare that they have no conflict of interest.
Ethical Approval
The study was approved by local ethics committee for psychologists at the University Hospital of Hamburg-Eppendorf in Germany (LPEK-0441d) in accord with the 7th revision of the Declaration of Helsinki.
Informed Consent
All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (national and institutional). Informed consent was obtained from all individual subjects participating in the study.
Human and Animal Participants
All institutional and national guidelines for the care and use of laboratory animals were followed
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