The Effectiveness of Psychological Interventions for Obsessive-Compulsive disorder

In this thesis, we examined the effectiveness of psychological interventions for obsessive-compulsive disorder (OCD), with the aim of addressing critical questions such as which treatments are most beneficial for specific groups. The study highlights important implications for clinical practice as well as existing gaps in OCD research. Psychological interventions are effective in the treatment of OCD, not only reducing symptom severity but also alleviating comorbid anxiety and depressive symptoms while improving overall quality of life. Various psychological approaches have demonstrated comparable effectiveness and acceptability. As the gold-standard treatment, cognitive-behavioral therapy (CBT) has been successfully delivered in multiple formats, most of which show similar outcomes in terms of efficacy and patient acceptability. An exception is unguided self-help CBT, which has proven less effective and less acceptable. Nevertheless, unguided self-help interventions still yield moderate reductions in OCD symptom severity, highlighting their potential to expand access to evidence-based care for individuals with OCD. The current findings carry important implications for individuals with OCD, professionals, and researchers. For individuals with OCD, a range of psychological interventions and delivery formats are available, many of which demonstrate comparable effectiveness. For those facing barriers to treatment-such as financial constraints, geographical limitations, or stigma-unguided self-help interventions may serve as a viable option. For professionals, the need to provide personalized treatment tailored to patients’ clinical and personal characteristics and preferences is paramount. Establishing datasets that systematically code these characteristics would significantly advance the development of individualized treatment approaches. For researchers, it is strongly recommended to investigate potential moderators and predictors of treatment outcomes at the patient level, as well as to pursue strategies that expand access to evidence-based interventions.