[Update on obsessive-compulsive and related disorders]

Obsessive-compulsive disorders (OCD) are common and have high treatment resistance rates. The rationale of this CME article is to provide an update on OCD in adulthood. First, recent study results on the etiopathogenesis of OCD and its correlates are summarized and the clinical manifestations and current classification criteria are presented. Insight specifiers were added in the ICD-11 criteria and the classification into subtypes and the time criterion were removed; instead, the criteria now require the symptoms to be time-consuming (e.g., lasting > 1 h/day). In addition, a separate category for obsessive-compulsive and related disorders has been introduced. Frequent mental comorbidities, which are present in approximately 70-90% of cases and differential diagnostic considerations are summarized. The current state with respect to the diagnostic work-up and secondary (e.g., autoimmune) obsessive-compulsive syndromes is outlined. In terms of treatment options, disorder-specific cognitive behavioral therapy with exposure and response prevention has demonstrated high effect sizes. Novel approaches and formats include concentrated short-term or internet-based interventions. Pharmacotherapy is primarily carried out with serotonin reuptake inhibitors (SSRIs or clomipramine). Atypical antipsychotic drugs can be used for augmentation. Glutamate modulators are currently being investigated in clinical trials. Brain stimulation techniques, including noninvasive repetitive transcranial magnetic stimulation and invasive bilateral deep brain stimulation, are therapeutic options in cases of treatment resistance. Finally, a short summary delineates other OCD-related disorders. New diagnostic and treatment options to reduce the treatment resistance rates seem promising.