Shape analysis of subcortical structures in obsessive-compulsive disorder and the relationship with comorbid anxiety, depression, and medication use: A meta-analysis by the OCD Brain Imaging Consortium

Effects of antidepressants on brain structure and function in patients with obsessive-compulsive disorder: A review of neuroimaging studies

Obsessive-compulsive disorder (OCD) affects 2-3% of people worldwide. Although antidepressants are the standard pharmachological treatment of OCD, their effect on the brain of individuals with OCD has not yet been fully clarified. We conducted a systematic search on PubMed, Scopus, Embase, and Web of Science to explore the effects of antidepressants on neuroimaging findings in OCD. Thirteen neuroimaging investigations were included. After antidepressant treatment, structural magnetic resonance imaging studies suggested thalamic, amygdala, and pituitary volume changes in patients. In addition, the use of antidepressants was associated with alterations in diffusion tensor imaging metrics in the left striatum, the right midbrain, and the posterior thalamic radiation in the right parietal lobe. Finally, functional magnetic resonance imaging highlighted possible changes in the ventral striatum, frontal, and prefrontal cortex. The small number of included studies and sample sizes, short durations of follow-up, different antidepressants, variable regions of interest, and heterogeneous samples limit the robustness of the findings of the present review. In conclusion, our review suggests that antidepressant treatment is associated with brain changes in individuals with OCD, and these results may help to deepen our knowledge of the pathophysiology of OCD and the brain mechanisms underlying the effects of antidepressants.

Exploring the relationship between context and obsessions in individuals with obsessive-compulsive disorder symptoms: a narrative review

Obsessions in obsessive-compulsive disorder (OCD) have long been proposed to differ from intrusive thoughts in unaffected individuals based on appraisal of the thoughts. However, more recent research indicates that cognitive processes behind obsessions may differ significantly from those in healthy individuals concerning their contextual relationship. This narrative literature review summarizes current evidence for the role of context-relatedness for obsessions in OCD and intrusive thoughts in affected and unaffected individuals. The review encompasses a total of five studies, two of which include individuals diagnosed with OCD (one study also includes a group of unaffected control individuals), while the other three studies investigate the relationship between OCD symptoms and context in unaffected individuals. As assessed by mainly self-reports, the review examines the connection between thoughts and their context, shedding light on how the repetition and automaticity of thoughts, as well as their detachment from context over time contribute to defining obsessions in contrast to intrusive thoughts. However, the link with context depends on the content of the obsessions. We propose the term "decontextualization of thoughts" to describe the phenomenon that obsessions gradually lose their connection with external context during the development of OCD. Future research should investigate whether this hypothesis can be supported by experimental evidence and identify whether this shift might be more likely a cause or a consequence of the disorder.

Phenomenological Considerations of the World of the Obsessive Patient

Despite significant scientific advances in research on obsessive-compulsive disorder (OCD), the psychological and behavioral symptoms of this pathological condition remain hard to understand, until they seem paradoxical. The present work seeks to consider the significance and potential contribution of a phenomenological reading of OCD and how phenomenalism has influenced some cognitive models of this disorder. Transcendental phenomenology is a philosophical approach that attaches primary importance to intuitive experience and considers all phenomena intrinsically associated with the subject's inner world. Thus, the subject's intuition is considered the starting point for understanding their essential experience. This approach has had a profound influence on modern cognitive sciences. Among current cognitive models, post-rationalist cognitivism and cognitive neuropsychological psychotherapy seem most effective in capturing the world experiences of OCD patients. Both apply a phenomenological approach to identify these experiences, which are typically characterized by hyper-reflexivity, at the expense of 'natural evidence.' The models have found that OCD patients experience the world emotionally as a sterile set of rules, and this experience determines their suffering.