Perfectionism as Possible Predictor for Treatment Success in Mindfulness-Based Cognitive Therapy and Metacognitive Training as Third-Wave Treatments for Obsessive-Compulsive Disorder

Identifying predictors of treatment outcome is crucial in trying to improve treatment success (Olatunji et al., 2013). Taking into consideration that not all patients benefit from the same treatment in the same way (Blatt et al., 2010), determining prognostic indicators may guide treatment selection, particularly for patients at risk of poorer outcome, and thus optimize use of limited healthcare resources (Knopp et al., 2013). This seems especially relevant for a disorder such as obsessive-compulsive disorder (OCD). Even though evidence-based treatments such as Cognitive-Behavioral Therapy (CBT, with or without exposure) exist for OCD, drop-out rates are high (Hezel & Simpson, 2019; Ong et al., 2016) and maintenance of treatment effects is limited (Cabedo et al., 2018). Hence, finding ways to improve treatments and treatment selection for these patients is essential.

Aside from commonly used outcome predictors such as demographic variables, symptom characteristics, and comorbidity (see Knopp et al. (2013) for a review), an increasing number of studies have been investigating the impact of cognitions relevant to OCD. Of particular interest are key beliefs such as intolerance of uncertainty or inflated responsibility, which have been identified as core cognitive domains of OCD (Obsessive Compulsive Cognitions Working Group, 1997).

One such core cognitive domain of OCD is perfectionism, illustrating its assumed key role in the etiology and maintenance of the disorder. In general, perfectionism can be understood as “the tendency to set high standards and employ overly critical self-evaluations” (Frost & Marten, 1990, p. 559). Research suggests perfectionism to be a multidimensional construct, with factor analyses consistently generating two factors: perfectionistic strivings and perfectionistic concerns (Stöber & Otto, 2006). Perfectionistic strivings encapsulate setting high standards in order to strive for perfection, whereas perfectionistic concerns refer to a concern over mistakes, doubts about one’s actions and abilities, and self-criticism (Frost et al., 1990). Both dimensions of perfectionism have been linked to psychopathology, yet perfectionistic strivings have been found to be especially relevant for eating disorders, whereas perfectionistic concerns yield larger and more consistent effects for OCD, depression, and anxiety disorders (Limburg et al., 2017). In an attempt to better capture the clinically relevant aspect of perfectionism, the term “clinical perfectionism” was introduced. Conceptualized as an “overdependence of self-evaluation on the determined pursuit of personally demanding, self-imposed standards in at least one highly salient domain, despite adverse consequences” (Shafran et al., 2002, p. 778), it differs from the multidimensional construct mentioned above in that it puts central emphasis on the self-worth relying on achieving high standards. This includes biased performance evaluation, self-criticism if standards are not met, and reappraising standards as insufficiently demanding if they are met. In this article, we will be homing in on perfectionistic concerns and clinical perfectionism when discussing the impact of perfectionism on treatment success. Patients with OCD report significantly higher levels of perfectionism compared to nonclinical controls (Antony et al., 1998a, 1998b; Miegel et al., 2020b), both globally and on the dimension “concern over mistakes” in particular (Boisseau et al., 2013; Sassaroli et al., 2008). In a meta-analysis, perfectionistic concerns are significantly correlated with both a diagnosis of OCD and symptoms of OCD (Limburg et al., 2017).

Perfectionism has been shown to limit success of CBT treatments—in both individual and group settings—across mood (Blatt et al., 1995, 1998; Hawley et al., 2022), anxiety (Ashbaugh et al., 2007; Mitchell et al., 2013), and eating disorders (Bizeul et al., 2001; Sutandar-Pinnock et al., 2003). Several hypotheses exist on how perfectionism reduces treatment success. It could be that patients with higher levels of perfectionism may struggle building a stable alliance with their therapist (Blatt & Zuroff, 2002; Zuroff et al., 2000), feel ambivalent about change and thus respond with more rigidity (Egan et al., 2011), or pay particularly selective attention to slow treatment gains (Shafran et al., 2002). These challenges may arise in OCD specifically, when cognitions typical of OCD, such as intolerance of uncertainty and inflated responsibility, interact disadvantageously with perfectionism. For instance, a patient with OCD may not only believe that executing an exercise in a perfect manner is possible (perfectionistic belief), but indeed necessary, because even minor mistakes could cause serious harm (inflated sense of responsibility) (Obsessive Compulsive Cognitions Working Group, 1997). This could lead to patients either trying too hard to be “the perfect patient” or avoiding engaging with exercises altogether (Pinto et al., 2011).

Indeed, the impeding effect of perfectionism on CBT treatment effects extends to OCD as well (Kyrios et al., 2015; Manos et al., 2010; Pinto et al., 2011). This has been demonstrated in both individual and group settings (Chik et al., 2008). However, results on the predictive qualities of perfectionism in the treatment of OCD have been inconsistent. Kyrios et al. (2015) investigated several predictors of outcome in individual CBT treatment for OCD over 16 weeks. They found that both baseline perfectionism and baseline to post-treatment change in perfectionism were significant predictors of clinician-rated OCD symptom severity at post-treatment, while controlling for baseline symptom severity. The perfectionism change score especially has repeatedly been shown to be a significant predictor of treatment outcome (Manos et al., 2010), preceding behavioral symptom reduction (Wilhelm et al., 2015). A recent study by Wheaton et al. (2020), for instance, examined the impact of perfectionism in an inpatient setting. While their analyses yielded no significant effect of baseline perfectionism on OCD outcome, changes in perfectionism did significantly account for clinician-rated OCD severity at post-treatment. Additionally, they could show that more perfectionistic patients stayed in treatment for a longer period. Other studies, however, showed no such effects. When investigating the effect of OCD-typical cognitions on outcome in 12-session individual CBT treatment, Woody et al. (2011) found that perfectionism consistently failed to predict clinician-rated obsessions at post-treatment. In an outpatient OCD treatment focused specifically on exposure (Su et al., 2016), perfectionism decreased significantly, but neither baseline perfectionism nor change in perfectionism were associated with clinician-rated OCD severity at post-treatment. Another study by Grøtte et al. (2015) sampled inpatients with OCD and found no significant change in perfectionism during intensive CBT treatment.

These inconsistencies may be partly due to different perfectionism measures being used. Most studies to date have measured perfectionism using the Obsessive Beliefs Questionnaire (OBQ; Obsessive Compulsive Cognitions Working Group, 2003, 2005), a measure developed to assess the above-mentioned core cognitions in OCD. The OBQ subscale “perfectionism/intolerance of uncertainty” compounds not only both perfectionistic strivings and perfectionistic concerns, but also the arguably separate facet of uncertainty tolerance. So far, only one study investigating the effect of perfectionism on OCD treatment outcome has used a specific perfectionism measure, namely the Frost Multidimensional Perfectionism Scale (FMPS; Frost et al., 1990). However, they found that only baseline scores on the subscale “doubts about actions” predicted clinician-rated OCD severity at post-treatment. This subscale was derived from a measure of OCD symptoms and has thus been argued to primarily reflect those symptoms, rather than perfectionism specifically (Shafran & Mansell, 2001). No study to date has investigated the role of clinical perfectionism in OCD treatment. In sum, perfectionism is assumed to be an important factor in OCD, yet its impact on treatment success requires further investigation. This is the case for both “classic” CBT treatment as well as younger treatment approaches which have been introduced in recent years.

These upcoming treatments include Mindfulness-Based Cognitive Therapy for OCD (MBCT; Külz et al., 2013, 2019) and Metacognitive Training for OCD (MCT-OCD; Jelinek et al., 2018; Miegel et al., 2020a, 2021). Both MBCT and MCT-OCD are treatments devised for the group setting and count among the so-called third-wave approaches, as in, they utilize CBT elements but specifically address experiential avoidance and foster distance from and acceptance of distress (Abramowitz et al., 2009). In MBCT the goal is for patients with OCD to accept rather than escape from their intrusive thoughts and difficult feelings, which may then reduce the need for compulsions (Fairfax, 2008; Hanstede et al., 2008). Small studies show significant reduction in OCD symptoms after MBCT treatment, compared to a waitlist-control (Key et al., 2017; Selchen et al., 2018). A recent randomized-controlled trial presents MBCT for OCD as superior to psychoeducation and equivalent to psychopharmacological treatment (Zhang et al., 2021). MCT-OCD, on the other hand, aims at helping patients to develop more cognitive flexibility (Rees & Anderson, 2013), in order to reduce the stress caused by disorder-specific cognitions (key beliefs, e.g., intolerance of uncertainty and perfectionism) and metacognitions (beliefs about one’s thoughts, e.g., action fusion) (Moritz & Lysaker, 2018). This is achieved through CBT techniques (e.g., cognitive and behavioural experiments) as well as third-wave strategies (e.g., acceptance and observing internal experiences from a distance) (Moritz et al., 2016). In an uncontrolled pilot study with an inpatient sample, a face-to-face version of MCT-OCD obtained a significant decline in OCD symptoms at post-treatment and a stable effect at 6-month follow-up (Miegel et al., 2020a). In a subsequent RCT, patients that participated at MCT-OCD decreased more compared to a care-as-usual control group in an outpatient sample with a medium effect size (η_p² = 0.078) (Miegel et al., 2021). Taken together, preliminary evidence shows both MBCT and MCT-OCD could be beneficial for patients with OCD.

The aim of the current study was to investigate perfectionism as a predictor of symptom outcome in third-wave group treatments (namely MBCT and MCT-OCD) for OCD. We were interested in examining the effect of both baseline perfectionism and the change in perfectionism on treatment outcome. To this end, we combined existing datasets from two randomized-controlled trials (Külz et al., 2019; Miegel et al., 2021), using baseline, post-treatment, and follow-up data. These data were submitted to multi-level analyses, since multi-level models allow for a flexible analysis of changes over time and let individuals vary in their baseline scores (random intercepts) and how they change (random slopes) (Curran et al., 2010). In addition to OCD symptoms, we assessed depressive symptoms as a secondary outcome, since OCD and depression are highly comorbid (Brakoulias et al., 2017; Rickelt et al., 2016) and perfectionistic concerns are closely related to depression (Smith et al., 2021). In extension of previous studies, we used pertinent questionnaire measures, namely the Frost Multidimensional Perfectionism Scale (FMPS; Frost et al., 1990) and the Clinical Perfectionism Questionnaire (Fairburn et al., 2003), to assess concern over mistakes and clinical perfectionism specifically. To the best of our knowledge, this makes the current study the first to examine clinical perfectionism as a predictor of OCD treatment outcome.

We hypothesized that greater perfectionism at baseline would predict greater OCD symptom severity at post treatment and follow-up (H1), controlling for symptom severity at baseline. We further expected that a greater decrease in perfectionism from baseline to post-treatment would predict lower OCD symptom severity at follow-up (H2), controlling for symptom severity at post-treatment. Both hypotheses were tested for one primary outcome, namely clinician-rated OCD symptom severity (H1 and H2), and two secondary outcomes, namely self-rated OCD and depressive symptom severity (H3 and H4). The study was preregistered before data analysis (https://​osf.​io/​hjfst/​).

The present study investigated the impact of perfectionism, particularly concern over mistakes and clinical perfectionism, on treatment outcome in MBCT for OCD and MCT-OCD. To our knowledge, this is the first study to examine whether perfectionism predicts treatment outcome in third-wave treatments for OCD. Additionally, this is the first study to explore clinical perfectionism as an impending factor for OCD treatment success.

Neither concern over mistakes (FMPS-CM) nor clinical perfectionism (CPQ) at baseline were significantly related to OCD treatment outcome (Y-BOCS or OCI-R). This is in contrast to some prior reports showing an association between greater baseline perfectionism and poorer OCD outcome (Chik et al., 2008; Kyrios et al., 2015; Manos et al., 2010; Pinto et al., 2011). However, there have been previous studies which also failed to find such a predictive effect in OCD treatment (Su et al., 2016; Wheaton et al., 2020; Woody et al., 2011). Part of the reason behind this could simply be that the predictive effect of concern over mistakes is relatively small and not detectable within a small sample such as ours. Indeed, in previous studies perfectionism accounted for only a small proportion of change in OCD symptoms. Another reason for these inconsistencies, as outlined above, could be the use of the OBQ as a perfectionism measure (Kyrios et al., 2015; Manos et al., 2010), which combines the perfectionism subscale with a subscale on “intolerance of uncertainty”. Interestingly, the one study which also used the FMPS (Chik et al., 2008) found an effect only for the subscale “doubts about actions”, the use of which we have criticized above, but no effect for “concern over mistakes” (FMPS-CM). Our replication of this null effect seems to suggest that concern over mistakes may play less of a role in OCD treatment than previously assumed. Future research may need to assess concern over mistakes and intolerance of uncertainty with separate distinct measures (e.g., using FMPS-CM and the Intolerance of Uncertainty Scale (Buhr & Dugas, 2002)), ideally in larger patient samples, in order to parse effects observed using the OBQ. Another reason for our null results could be related to the type of treatment provided. Considering the scarcity of extant literature on perfectionism in group treatments for OCD, it may be that perfectionism has less of an impact in the current group setting than it does in previous studies which examined individual treatment. There is, however, sufficient evidence for an impeding effect of perfectionism in group treatments for mood and anxiety disorders (Ashbaugh et al., 2007; Hawley et al., 2022; Mitchell et al., 2013), and one study showing this effect for OCD (Chik et al., 2008). Thus, rather than the manner of treatment presentation, the content of third-wave approaches may account for our null results. Previous studies investigated exclusively “classic” CBT treatments for OCD. Whereas both MCT-OCD and MBCT draw on CBT techniques, they additionally promote a non-judgmental and accepting attitude, which may in fact attenuate the disadvantageous effect of perfectionism. Through being encouraged to view mistakes as an opportunity to learn rather than a reason to criticize themselves (Leeuwerik et al., 2020), patients may have been able to be more open towards exercises and their outcomes. This explanation would be in line with at least one of the two perfectionism measures (CPQ) changing significantly through treatment in our sample. Replication by future studies on third-wave treatments for OCD, such as Acceptance Commitment Therapy (Twohig et al., 2014), will need to ascertain this finding. Additionally, further research is needed on potential differences between individual and group settings, both for CBT and third-wave treatments.

Contrary to our expectations, only reductions in clinical perfectionism (CPQ) predicted recovery from OCD symptoms (Y-BOCS), but not reduction in concern over mistakes (FMPS-CM). Change in clinical perfectionism preceded symptom change. Several previous studies have found an effect of change in perfectionism on OCD treatment outcome (Kyrios et al., 2015; Manos et al., 2010; Wheaton et al., 2020; Wilhelm et al., 2015). However, the one study which also used the FMPS to measure concern over mistakes found only an effect of baseline perfectionism, but not of change in perfectionism on OCD treatment outcome (Chik et al., 2008). Since the CPQ, in contrast to the FMPS, was created specifically with the purpose of measuring change within treatment (Fairburn et al., 2003), it is perhaps not surprising that it would turn out to be the more change-sensitive measure. Moreover, the CPQ measures both concern over mistakes and adherence to unrealistic expectations that interfere with one’s functioning (Shafran & Mansell, 2001). This may contribute to the CPQ measuring the aspects of perfectionism most relevant to a clinical sample and experiences throughout treatment. There are in fact CBT treatments that target clinical perfectionism which result in reductions not only of clinical perfectionism, but also psychopathology such as anxiety, depression, and eating disorders (see Galloway et al., 2022 for a meta-analysis), presenting change in clinical perfectionism as a promising process of therapeutic change. In this current study, CPQ data was available only for the MCT-OCD group of the sample, a treatment that dedicates a whole module to acceptance in the face of “imperfections”. Our findings indicate that MCT-OCD is effective in reducing clinical perfectionism. While we could not investigate this effect for the MBCT group of the sample, a recent study with OCD patients suggests MBCT to be effective in reducing perfectionism as well (Mathur et al., 2021). It is important to note, however, that our analyses using the CPQ were merely exploratory. The model which showed the best fit included change in clinical perfectionism as the only predictor, with OCD symptoms at post-treatment having been eliminated through data-driven model fitting. This means that the effect of change in clinical perfectionism (CPQ) was not controlled for post-treatment symptom severity, whereas the model investigating change in concern over mistakes (FMPS-CM) was. This may offer another explanation as to why only change in clinical perfectionism yielded a predictive effect. Since the current study was the first to look at clinical perfectionism as a predictor of OCD outcome, this finding will need to be replicated.

Whereas concern over mistakes (FMPS-CM) did not predict OCD symptoms in our sample, it did indeed predict depressive symptoms (BDI-II) across time points. This fits in with extant literature for both healthy and patient samples (see Smith et al., 2021 for a recent meta-analysis). Overall, meta-analytic effect sizes regarding the relationship between concern over mistakes and symptom severity are larger for depression than OCD (Limburg et al., 2017), which may render effects more easily detectible in depression compared to OCD. Aside from effect sizes, another explanation may lie in treatment specificity. It seems the eight-week treatment programs investigated in this current study sufficed to treat an adverse association between perfectionism and the core OCD symptoms targeted by group modules. They may not have been enough, however, to curb the impeding effect of perfectionism in the recovery from comorbid symptoms on top of that, be it because treatments were too specific to OCD or not intense enough for more severely ill patients (i.e., those suffering from comorbid disorders). Interestingly, even though MCT is assumed to target beliefs relevant across disorders, previous MCT studies have found no significant reduction of comorbid depression symptoms in patients with OCD (Miegel et al., 2021; Rees & van Koesveld, 2008). It is possible that this is due to a more obstructive effect of perfectionism in regard to comorbid symptoms. Finally, a purely methodological explanation for the discrepancy between our findings for OCD and depressive outcomes lies in our control measures. Since no second depression measure was available, we controlled for baseline OCD symptom severity when predicting both the OCD measures and the depression measure. Compared to an OCD outcome controlled for OCD symptoms, a depression outcome controlled for OCD symptoms should leave more variance in the data.

Taken together, our results highlight the need for further research in order to isolate the role of perfectionism in OCD treatment. Pre-treatment levels of perfectionism may not have such a strong obstructive effect on outcome in third-wave treatments (e.g., MBCT and MCT-OCD) as they do in classic CBT. In this context, effects on comorbid disorders such as depression, as well as change in clinical perfectionism as a possible mechanism of symptom change, will require particular attention.