Generalized Anxiety Disorder Symptoms in Adolescents: The Relative Contribution of Intolerance of Uncertainty and Metacognitive Beliefs

Generalized anxiety disorder (GAD) is linked to dispositional worry proneness and characterized by excessive and perceived uncontrollable worry about a variety of topics. In individuals with GAD, worrying is accompanied by substantial emotional distress and symptoms such as sleep difficulties, concentration problems, exhaustion, irritability, and somatic symptoms [1]. Worry has further been identified as a transdiagnostic process across anxiety disorders and major depression (e.g.,[2, 3]) and it has therefore been suggested that excessive worry can account for comorbid symptoms and disorders, including depression, which is commonly observed in those with GAD [4, 5]. GAD is one of the most common anxiety disorders in adolescence [5] with prevalence increasing from early teens and found to be evident in as much as 4.5% of 14-year-olds [6]. Also, prevalence of adolescent GAD is found to be nearly three times higher for girls than for boys measured at the same age [6].

While being both prevalent and associated with high levels of functional impairment, remission rates following treatment, which is most often a disorder-general form of cognitive behavioral therapy (CBT), are only around 50% [7]. More specifically, a recent systematic review on the efficacy of psychological therapies specifically for youth with a primary diagnosis of GAD found limited available empirical research [8]. They conclude that there is a need for more disorder-specific research and analyses of outcomes and mechanisms specific to GAD as there is substantial room and a pressing need for better knowledge and interventions. A good starting point can be to identify the underlying processes driving emotional distress symptoms such as anxiety and depression, and the chronic worry disposition characteristic of the disorder.

Several theoretical models have identified key maintenance factors associated with GAD, and the treatment approaches derived from these models—though primarily developed for adults—may hold relevance for adolescents as well (see [9] for an overview). The Intolerance of Uncertainty-model (IU-model; [10]) and the Metacognitive Model (MC-model; [11]) are two models which have received substantial empirical support for their proposed mechanisms and thus have potential to improve understanding and treatment of adolescent GAD. Importantly, they differ in which mechanisms are presumed to be the most central, with the implication that they propose different treatment targets and interventions. Hence, it is important to establish which of these factors play the most significant role in accounting for GAD symptoms.

The IU-model [10, 12] captures how perceived uncertainty is interpreted as a sign of danger, which triggers reactions that increase distress. IU was first defined as a trait-like phenomenon of “cognitive, emotional and behavioral reactions to uncertainty in everyday life situations” ([13] p. 792). A revised definition describes IU as a dispositional inability to tolerate the perception of uncertainty, resulting in aversive responses [14]. IU beliefs (e.g., “unforeseen events upset me greatly” or “uncertainty makes life intolerable”) triggers positive beliefs about worry, persistent worrying, and a negative problem-solving approach, which ultimately increases the use of avoidance strategies and maintains symptoms. Empirical studies support the role for IU in adolescent GAD and in the etiology of worry (e.g., [15]), IU is elevated in adolescents with GAD compared to healthy controls [16] and shows a positive relationship with anxiety [17] and depression symptoms [18]. Furthermore, a pilot randomized controlled trial of CBT targeting IU specifically in adolescent GAD (aged 10–18 years old) reported an 80% remission rate and a strong effect on comorbid depression symptoms [19], which is consistent with an association between the assumed mechanism (i.e., IU) and improvement from GAD and its related symptoms.

The Metacognitive model [11, 20] emphasizes biases in metacognition (i.e., beliefs about worrying) as the most important mechanism of GAD. The model suggests two domains of metacognitive beliefs that underly maladaptive self-regulation strategies such as worrying which further perpetuate distress. Positive metacognitive beliefs about worry (e.g., “worrying helps me cope”) are thought to contribute to the use of worry as a coping mechanism in response to internal and external stressors. Furthermore, negative metacognitive beliefs about worry, regarding the uncontrollability and perceived dangers of worry (e.g., “worry is uncontrollable”) hinder disengagement from the worrying process which exacerbate distress. Furthermore, worry itself may become a perceived threat due to negative beliefs about worrying (e.g., “worrying can make me go crazy”), a phenomenon referred to as meta-worry which is simply put “worry about worry” [21]. Hence, negative metacognitive beliefs about worry are considered the most important knowledge structure in GAD and in other emotional disorders and psychological functioning more generally due to their negative impact on self-regulation [20]. Empirical studies support the role of metacognitive beliefs, particularly negative metacognitive beliefs about worry in emotional disorders and distress in adolescents (see [22] for a meta-analysis). Although both positive and negative metacognitive beliefs are found to be elevated in adolescents with GAD, negative metacognitive beliefs about worry appear to have the strongest relationship with clinical status and the magnitude of anxiety and depressive symptoms [22]. While there are no studies of Metacognitive therapy (MCT; [20]) specifically for adolescent GAD, an open trial evaluating group-MCT for GAD in children reported an 86% remission rate with substantial effects on comorbid disorders and symptoms including depression [23]. The effects observed in this study support an association between change in dysfunctional metacognition (which is the primary target in MCT) and improvement from GAD and its related symptoms in children.

While several studies have compared the contribution of IU and metacognitive beliefs to GAD symptoms in adults [24‐26], no study has investigated these belief domains within adolescent GAD. The relative contribution of IU and metacognitions in young people have been examined in two previous studies though, both focusing on worry as the outcome. The first of these investigated children 12 years or younger [27] and reported that negative metacognitive beliefs were the strongest predictor in the overall sample. However, IU and positive metacognitive beliefs were more strongly associated with worry when they isolated “high-worriers” indicating a relationship that is dependent on worry severity. The second study included adolescents and young adults gathered at convenience (15–20-year-olds) [28], and reported that intolerance of uncertainty, positive and negative metacognitive beliefs, accounted for independent and unique variance in worry. Here, negative metacognitive beliefs accounted for the most variance in the final step of the regression. These studies indicate a role for negative metacognitive beliefs and IU to worry in children and adolescents. However, several questions remain unanswered such as the relative role for these belief domains to GAD symptoms more broadly in adolescents, particularly among those with elevated anxiety.

In the current study, we aimed to test the relative contribution of IU and metacognitive beliefs to anxiety, depression and chronic worry in adolescents with analog GAD. Testing the relative importance of these belief domains in adolescents can inform which of them should be emphasized in treatment interventions (i.e., focusing on perception of uncertainty as in IU-CBT versus working on mental regulation as in MCT).

Since GAD is found to be nearly three times more prevalent in females [6], sex was controlled to isolate the unique contribution of the predictors that are amenable to change. The potential contribution from depression to anxiety and vice versa was controlled in these analyses with an aim to evaluate unique relationships between the outcomes and the belief domain predictors. In evaluating the role for the predictors in question to chronic worry, we also controlled both anxiety and depression symptoms before entering the competing belief domains to rule out the potential role for transient emotional distress in predicting chronic worry (i.e., GAD vulnerability/disposition). As positive beliefs about worry (PBW) are included in both theoretical models but also assigned a less important role to the maintenance of distress and disorder, we controlled this variable on a separate step before entering IU and NBW on subsequent steps. In line with the theoretical models and existing research, we expected that intolerance of uncertainty (IU) and negative metacognitive beliefs about worry (NBW) would uniquely and independently explain variance in symptoms of anxiety, depression and chronic worry beyond the covariates. Across analyses, we were naturally interested in which of the competing belief domains that most reliably correlated with outcomes as it could be considered an indicator of which domain that should be prioritized in formulation and interventions. We predicted that NBW would emerge as the more reliable and unique correlate of outcomes consistent with research in adults showing that negative metacognitive beliefs about worry rather than cognitive beliefs are strongly and specifically associated with symptom improvement in treatment of emotional disorders [29].

The Screen for Child Anxiety-Related Emotional Disorders (SCARED; [33, 34]) was used to assess anxiety symptoms. SCARED is widely utilized and has demonstrated strong psychometric properties in both clinical and community samples (e.g., [35, 36]). The version used in this study consists of 41 items assessing experiences over the past three months (e.g., “When I feel frightened, it is hard for me to breathe” or “I get headaches when I am at school”) rated on a 3-point scale: “Almost never,” “Sometimes,” and “Often.” A total score is calculated from these items, with higher scores indicating more symptoms. The internal consistency of the SCARED in the current sample was excellent (α = 0.94).

Depressive symptoms were assessed by the Short Mood and Feelings Questionnaire (SMFQ; [37]) which consists of 13 items (e.g., “I didn’t enjoy anything at all” or “I cried a lot”) rated on a 3-point scale (0 ="Not true”; 1= “Sometimes true”; to 2 ="True”) and captures symptoms evident the past two weeks. Higher scores reflect higher depression severity. The SMFQ has demonstrated a strong correlation with the full 33-item Mood and Feelings Questionnaire (MFQ; [37]), which is recommended for depression screening in children and adolescents by the National Institute for Health and Clinical Excellence (NICE, [38]). The internal consistency of the SMFQ in the current sample was good (α =.84).

The Penn State Worry Questionnaire for Children – Brief Version (PSWQ-brief; [39]) was used to assess chronic worry. This abbreviated self-report measure, adapted from the original 16-item Penn State Worry Questionnaire

(PSWQ; [40]), consists of five items (e.g., “when I am under pressure, I worry a lot” or “I am always worrying about something”) rated on a scale from 1 to 5, with higher scores indicating a greater degree of chronic worry. The PSWQ-brief version has been validated in adolescents, demonstrating good psychometric properties (e.g., [39]). The internal consistency for PSWQ-brief version in the current sample was excellent (α =.92).

The Intolerance of Uncertainty Scale-12 (IUS-12; [41]) is a shortened version of the original Intolerance of Uncertainty Scale (IUS; [13]), designed to measure an individual’s tendency to perceive ambiguous situations, uncertainty, and future events as distressing (e.g., “Unpredicted events upset me a great deal”). Items are rated on a 5-point Likert scale. The IUS-12 has demonstrated strong psychometric stability, excellent internal consistency, and a high correlation with the original scale (e.g., [41, 42]). Reliability has also been demonstrated in adolescent populations [43] and the internal consistency of the scale in the present sample was excellent (α = 0.92).

The Metacognitions Questionnaire-30 (MCQ-30; [44]) was used to assess two key factors of the metacognitive model of worry and generalized anxiety disorder [11]: (1) Positive beliefs about worry (e.g., “Worrying helps me solve problems”) and (2) Negative beliefs about its uncontrollability and perceived danger (e.g., “When I start to worry, I cannot stop”). The MCQ-30 originally developed for adults has recently been validated for adolescents with sound psychometric properties down to 16 years old [45]. In the current study, the internal consistency for both subscales were found to be good; α = 0.84 for positive beliefs about worry and α = 0.86 for negative beliefs about worry.

Statistical analyses were performed by using Statistical Product and Service Solutions (SPSS), version 29. As preliminary analyses, bivariate correlations and mean scores for the six included variables were calculated. To test the relative importance of intolerance of uncertainty and metacognitive beliefs in explaining anxiety, depression, and chronic worry in adolescent analog GAD, we undertook three separate linear hierarchical regression analyses. In the first analysis, anxiety served as the dependent variable. Sex was entered as a control in step 1, followed by depression in step 2, positive beliefs about worry in step 3, intolerance of uncertainty in step 4 and finally, negative metacognitive beliefs about worry in step 5. In the second analysis, depression was the dependent variable. Sex was controlled for in step 1, anxiety in step 2, positive beliefs about worry in step 3, intolerance of uncertainty in step 4 and negative metacognitive beliefs about worry were included in the final step. In the third analysis, chronic worry was used as the dependent variable. Sex was controlled in step 1, followed by anxiety and depressive symptoms in step 2, positive beliefs about worry in step 3, intolerance of uncertainty in step 4, and negative metacognitive beliefs about worry in step 5.

When depression symptoms were treated as the dependent variable, and we controlled for anxiety, only negative metacognitions about worry (NBW) significantly predicted depressive symptoms. Positive beliefs about worry and intolerance of uncertainty did not account for additional variance after controlling anxiety symptoms (Table 3).

When using chronic worry as the dependent variable (Table 4), we found that anxiety and depression as a block accounted for a substantial additional part of the variance of which anxiety made a unique and independent contribution (Step 2). In step 3, positive beliefs about worry accounted for additional variance when controlling sex and anxiety and depression symptoms but became non-significant when adding intolerance of uncertainty in the fourth step which accounted for an additional 2% of the variance. In the final step of the model, when all variables were included, intolerance of uncertainty was no longer significant, but anxiety and negative metacognitive beliefs about worry showed a unique and independent association with chronic worry.

In the current study, we aimed to examine the independent and relative contributions of intolerance of uncertainty and negative metacognitive beliefs to anxiety and depression symptoms, and chronic worry, in a sample of adolescents with analog GAD.

We found that IU accounted for unique variance in anxiety symptoms but not in depression or chronic worry. Negative metacognitive beliefs about worry explained unique variance across all outcomes, though. Among the included covariates, female sex was uniquely associated with anxiety but not with depression or chronic worry. Anxiety was uniquely associated with chronic worry but not with depression. Depression and positive metacognitive beliefs about worry were not significant as unique predictors in any of the final models.

Consistent with the IU model [10], intolerance of uncertainty (IU) was uniquely associated with anxiety symptoms, aligning with previous findings in adolescent GAD (e.g., [16, 19]). However, IU did not show a unique association with depression when controlling anxiety symptoms, raising questions about its specific relevance to depressive symptoms in adolescents with analog GAD and contradicting earlier results [19]. Although IU accounted for variance in chronic worry when controlling positive beliefs about worry, no unique relationship emerged with chronic worry when controlling for negative beliefs about worry (NBW). This finding resembles the two previous studies comparing IU and metacognitive beliefs as predictors of worry, although those studies reported a small but significant contribution of IU beyond negative metacognitive beliefs about worry [27, 28].

Earlier results suggesting a strong role for intolerance of uncertainty (IU) in adolescent GAD may reflect that negative metacognitive beliefs about worry (NBW) were not controlled (e.g., [16, 19]). Alternatively, the discrepancies may reflect differences in study design, sample severity, unmeasured confounding variables, or random variation. However, the current results align with the metacognitive model of GAD [11] and adult studies where NBW has been found to better account for variance in worry severity and GAD symptoms compared to IU [25]. It might be plausible that IU itself represents a cognitive manifestation of anxiety, influenced by higher-order processes. For example, Wells [20] proposed that metacognitive biases—particularly negative beliefs about the uncontrollability and danger of thoughts—constitute a transdiagnostic mechanism underlying emotional distress and related dysfunction, including frequent negative appraisals of the self and the world. Notably, negative metacognitive beliefs about worry emerged in our analyses as the most reliable correlate of anxiety, depression, and chronic worry within analog GAD, remaining an independent predictor across outcomes even after controlling for overlapping symptom domains and IU. This finding supports the metacognitive model [20] and aligns with prior research in adults examining the relative contributions of IU and negative metacognitive beliefs about worry to anxiety symptoms (e.g., [46‐48]), and GAD [25] as well as GAD-treatment studies comparing metacognitive therapy and intolerance-of-uncertainty-focused interventions, where metacognitive therapy has demonstrated superior outcomes [49]; [50, 51].

Our adolescent findings further reinforce the notion that negative metacognitive beliefs can function as a transdiagnostic mechanism underlying diverse forms of emotional distress (e.g., [22, 29]), likely through their role in directing maladaptive self-regulation strategies [20]. Beliefs that worry is uncontrollable and dangerous may impair mental regulation, constitute psychological vulnerability beyond transient emotional states, and play a key role in comorbidity by maintaining worry and other maladaptive self-regulation strategies such as avoidance, rumination, and rigid self-attention [11, 52].

Our study found no evidence that positive metacognitive beliefs were uniquely associated with outcomes in adolescents with analog GAD when controlling for IU and negative metacognitive beliefs about worry. Consistent with theoretical models, this suggests that positive beliefs about worry might play a less central role in distress compared to IU and negative metacognitive beliefs. Shipp et al. [16] similarly reported that positive beliefs did not distinguish adolescents with GAD from a non-anxious community sample, although they were elevated in GAD compared to other anxiety disorders—indicating a potential role we could not examine in the current data. According to the metacognitive model [11], positive beliefs about worry are more relevant to the selection of coping strategies than to the maintenance or intensification of distress.

Our study carries potential clinical implications. Modifying intolerance of uncertainty (IU) may improve anxiety symptoms in adolescents with GAD, consistent with previous findings [19]. However, negative metacognitive beliefs about worry showed stronger and more consistent associations with GAD-related symptoms and vulnerability, supporting their role in maintaining distress and psychological vulnerability. Targeting these beliefs may yield broader therapeutic benefits. Metacognitive Therapy (MCT) was specifically designed to enhance mental regulation by addressing biases in metacognition, with negative metacognitive beliefs about worry considered central [20]. While this approach has proven effective in adults [53, 54], only one study is conducted in children [23], and there is therefore a need to evaluate the feasibility and effects associated with MCT in adolescents with GAD.

This study has limitations that need to be addressed. As the sample is based on cut-off scores from self-report, there is a risk of collider bias and replication in formally diagnosed adolescent samples is essential before firmer conclusions can be drawn. Secondly, the cross-sectional design limits causal inferences and leaves open the possibility of reverse effects, such as anxiety symptoms influencing belief domains. Research in adults suggests a reciprocal relationship between metacognitive beliefs and generalized anxiety symptoms, of which metacognitions play a dominant role (e.g., [55]), but this warrants investigation in adolescents. Moreover, the study did not collect information on participants’ ethnicity which impairs generalization and specific dysfunctional cognitive beliefs commonly associated with depression were not assessed or evaluated. Lastly, one of the items in the PSWQ-brief measure overlaps with the measurement of negative metacognitive beliefs. However, the variables are conceptually distinguishable and statistically intercorrelated but not entirely similar. Future studies should use longitudinal designs to strengthen causal interpretations and clinical applicability.

In conclusion, this study identifies negative metacognitive beliefs about worry as unique statistical predictors across symptom domains associated with adolescent GAD. Intolerance of uncertainty contributed independently to anxiety symptoms but not to depression or chronic worry. These findings support a role for both IU and negative metacognitive beliefs in adolescent GAD, with the latter emerging as the most consistent correlate. Clinically, this suggests that targeting negative metacognitive beliefs about worry may be a priority for reducing GAD-related symptoms. However, given the cross-sectional design and use of an analog sample, conclusions should be interpreted with caution. Nonetheless, our results indicate that theoretical models developed for adult GAD can inform adaptations for adolescents. Further research should examine the role of negative metacognitive beliefs about worry and associated mental regulation difficulties as potential mechanisms underlying disorder and distress in adolescent GAD.