Importance: Obsessive-compulsive disorder (OCD) is a neuropsychiatric disorder associated with significant impairment and a lifetime prevalence of 1% to 3%; however, it is often missed in primary care settings and frequently undertreated.Objective: To review the most current data regarding screening, diagnosis, and treatment options for OCD.Evidence Review: We searched PubMed, EMBASE, and PsycINFO to identify randomized controlled trials (RCTs), meta-analyses, and systematic reviews that addressed screening and diagnostic and treatment approaches for OCD among adults (≥18 years), published between January 1, 2011, and September 30, 2016. We subsequently searched references of retrieved articles for additional reports. Meta-analyses and systematic reviews were prioritized; case series and reports were included only for interventions for which RCTs were not available.Findings: Among 792 unique articles identified, 27 (11 RCTs, 11 systematic reviews or meta-analyses, and 5 reviews/guidelines) were selected for this review. The diagnosis of OCD was revised for the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, which addresses OCD separately from anxiety disorders and contains specifiers to delineate the presence of tics and degree of insight. Treatment advances include increasing evidence to support the efficacy of online-based dissemination of cognitive behavioral therapies, which have demonstrated clinically significant decreases in OCD symptoms when conducted by trained therapists. Current evidence continues to support the use of selective serotonin reuptake inhibitors as first-line pharmacologic interventions for OCD; however, more recent data support the adjunctive use of neuroleptics, deep-brain stimulation, and neurosurgical ablation for treatment-resistant OCD. Preliminary data suggest safety of other agents (eg, riluzole, ketamine, memantine, N-acetylcysteine, lamotrigine, celecoxib, ondansetron) either in combination with selective serotonin reuptake inhibitors or as monotherapy in the treatment of OCD, although their efficacy has not yet been established.Conclusions and Relevance: The dissemination of computer-based cognitive behavioral therapy and improved evidence supporting it represent a major advancement in treatment of OCD. Although cognitive behavioral therapy with or without selective serotonin reuptake inhibitors remains a preferred initial treatment strategy, increasing evidence that supports the safety and efficacy of neuroleptics and neuromodulatory approaches in treatment-resistant cases provides alternatives for patients whose condition does not respond to first-line interventions. [ABSTRACT FROM AUTHOR]