Mechanisms of cognitive-behavioral therapy effects on symptoms of body dysmorphic disorder: a network intervention analysis

Abstract

Background Body dysmorphic disorder (BDD) is a severe and undertreated condition. Although cognitive-behavioral therapy (CBT) is the first-line psychosocial treatment for this common disorder, how the intervention works is insufficiently understood. Specific pathways have been hypothesized, but only one small study has examined the precise nature of treatment effects of CBT, and no prior study has examined the effects of supportive psychotherapy (SPT). Methods This study re-examined a large trial (n = 120) comparing CBT to SPT for BDD. Network intervention analyses were used to explore symptom-level data across time. We computed mixed graphical models at multiple time points to examine relative differences in direct and indirect effects of the two interventions. Results In the resulting networks, CBT and SPT appeared to differentially target certain symptoms. The largest differences included CBT increasing efforts to disengage from and restructure unhelpful thoughts and resist BDD rituals, while SPT was directly related to improvement in BDD-related insight. Additionally, the time course of differences aligned with the intended targets of CBT; cognitive effects emerged first and behavioral effects second, paralleling cognitive restructuring in earlier sessions and the emphasis on exposure and ritual prevention in later sessions. Differences in favor of CBT were most consistent for behavioral targets. Conclusions CBT and SPT primarily affected different symptoms. To improve patient care, the field needs a better understanding of how and when BDD treatments and treatment components succeed. Considering patient experiences at the symptom level and over time can aid in refining or reorganizing treatments to better fit patient needs.

Mechanisms of Change in a Digital Five Ways to Wellbeing Intervention: A Network Intervention Analysis of a Randomized Controlled Trial

“…From this, it was inferred that CBT most likely affected subclinical depressive symptoms indirectly via its effects on symptoms of insomnia. In another study Bernstein et al (2023) examined effects of both CBT and suppor�ve psychotherapy on symptoms of body dysmorphic disorder. The two treatments affected different symptoms.…”

“…The two treatments affected different symptoms. This knowledge can be useful in making treatment fit beter with pa�ents' needs (Bernstein et al, 2023). Further, one study used NIA to explore symptom-specific effects of psychotherapy versus a combina�on of psychotherapy and pharmacological treatment for mild to moderate depression, documen�ng that combined therapy was more effec�ve than psychotherapy in the treatment of some depressive symptoms, but not others (Bekhuis et al, 2018).…”

“…We cannot, however, exclude the possibility that other unexamined aspects of mental health are influenced by the interven�on. As highlighted by others applying NIA (Bernstein et al, 2023), we have only focused on post-treatment measurements and important mechanisms that could be missing. We can only conclude that the network model es�mated with aggregated nodes represen�ng life sa�sfac�on, flourishing, and posi�ve emo�ons, revealed a direct effect on the later.…”

Network intervention analysis of anxiety-related outcomes and processes of acceptance and commitment therapy (ACT) for anxious cancer survivors

“…3 For these reasons, network intervention analysis provides a potentially promising alternative strategy to examining treatment processes of psychotherapy. It has typically been used to examine the direct and indirect effects of randomization to a psychotherapy intervention condition versus a control condition on symptoms of depression or other clinical presentations (e.g., Bernstein et al, 2021;Blanken et al, 2021;Boschloo et al, 2019). These past studies have 3 The standard mediation approach could, in theory, be extended to accommodate numerous process and outcome variables, and to model associations between many (or even all) variables in the model.…”

“…This study also has limitations. First, though the study's per-condition sample size was comparable to several other network intervention analyses (Bernstein et al, 2021;Blanken et al, 2019;Lancee et al, 2022), a larger sample would yield more precise network estimates. The current study's sample size also precluded adding additional nodes to examine PTSD or general anxiety symptom-specific network effects, and precluded examining whether there were subgroups of intervention responders that would be best captured by different network structures.…”