Obsessive–compulsive disorder

Obsessions are persistent unwanted thoughts, mental images, or urges that generate feelings of anxiety, disgust, or discomfort.^[8] Some common obsessions include fear of contamination, obsession with symmetry, the fear of acting blasphemously, the sufferer's sexual orientation, and the fear of possibly harming others or themselves.^[1][9] Compulsions are repeated actions or routines that occur in response to obsessions to achieve a relief from anxiety. Common compulsions include excessive hand washing, cleaning, counting, ordering, repeating, avoiding triggers, hoarding, neutralizing, seeking assurance, praying, and checking things.^[1][9][10] People with OCD may only perform mental compulsions such as needing to know or remember things. While this is sometimes referred to as primarily obsessional obsessive–compulsive disorder (Pure O), it is also considered a misnomer due to associated mental compulsions and reassurance seeking behaviors that are consistent with OCD.^[11]


Compulsions occur often and typically take up at least one hour per day, impairing one's quality of life.^[1][9] Compulsions cause relief in the moment, but cause obsessions to grow over time due to the repeated reward-seeking behavior of completing the ritual for relief. Many adults with OCD are aware that their compulsions do not make sense, but they still perform them to relieve the distress caused by obsessions.^{[1][8][9][12]} For this reason, thoughts and behaviors in OCD are usually considered egodystonic. In contrast, thoughts and behaviors in obsessive-compulsive personality disorder (OCPD) are usually considered egosyntonic, helping differentiate between the two.^[13]


Although the exact cause of OCD is unknown, several regions of the brain have been implicated in its neuroanatomical model including the anterior cingulate cortex, orbitofrontal cortex, amygdala, and BNST.^[14][1] The presence of a genetic component is evidenced by the increased likelihood for both identical twins to be affected than both fraternal twins.^[15] Risk factors include a history of child abuse or other stress-inducing events such as during the postpartum period or after streptococcal infections.^[1][16] Diagnosis is based on clinical presentation and requires ruling out other drug-related or medical causes; rating scales such as the Yale–Brown Obsessive–Compulsive Scale (Y-BOCS) assess severity.^[2][17] Other disorders with similar symptoms include generalized anxiety disorder, major depressive disorder, eating disorders, tic disorders, body-focused repetitive behavior, and obsessive–compulsive personality disorder.^[2] Personality disorders are a common comorbidity, with schizotypal and OCPD having poor treatment response.^[13] The condition is also associated with a general increase in suicidality.^[3][18][19] The phrase obsessive–compulsive is sometimes used in an informal manner unrelated to OCD to describe someone as excessively meticulous, perfectionistic, absorbed, or otherwise fixated.^[20] However, the actual disorder can vary in presentation, and individuals with OCD may not be concerned with cleanliness or symmetry.


OCD is chronic and long-lasting with periods of severe symptoms followed by periods of improvement.^[21][22] Treatment can improve ability to function and quality of life, and is usually reflected by improved Y-BOCS scores.^[23] Treatment for OCD may involve psychotherapy, pharmacotherapy such as antidepressants, or surgical procedures such as deep brain stimulation or, in extreme cases, psychosurgery.^{[4][5][24][25]} Psychotherapies derived from cognitive behavioral therapy (CBT) models, such as exposure and response prevention, acceptance and commitment therapy, and inference based-therapy, are more effective than non-CBT interventions.^[26] SSRIs are more effective when used in excess of the recommended depression dosage; however, higher doses can increase side effect intensity.^[27] Commonly used SSRIs include sertraline, fluoxetine, fluvoxamine, paroxetine, citalopram, and escitalopram.^[24] Some patients fail to improve after taking the maximum tolerated dose of multiple SSRIs for at least two months; these cases qualify as treatment-resistant and can require second-line treatment such as clomipramine or atypical antipsychotic augmentation.^{[4][5][27][28]} While SSRIs continue to be first-line, recent data for treatment-resistant OCD supports adjunctive use of neuroleptic medications, deep-brain stimulation, and neurosurgical ablation.^[29] There is growing evidence to support the use of deep brain stimulation and repetitive transcranial magnetic stimulation for treatment-resistant obsessive-compulsive disorder.^[30][31]


Obsessive–compulsive disorder affects about 2.3% of people at some point in their lives, while rates during any given year are about 1.2%.^[2][6] More than three million Americans suffer from OCD.^[32] According to Mercy, approximately 1 in 40 U.S. adults and 1 in 100 U.S. children have OCD.^[33] Although possible at times with triggers such as pregnancy, onset rarely occurs after age 35, and about 50% of patients experience detrimental effects to daily life before age 20.^{[1][16][2][34]} While OCD occurs worldwide,^[1][2] a recent meta-analysis showed that women are 1.6 times more likely to experience OCD.^[35] Based on data from 34 studies, the worldwide prevalence rate is 1.5% in women and 1% in men.^[35]

Prognosis

Quality of life is reduced across all domains in OCD. While psychological or pharmacological treatment can lead to a reduction of OCD symptoms and an increase in reported quality of life, symptoms may persist at moderate levels even following adequate treatment courses, and completely symptom-free periods are uncommon.^[215][216] In pediatric OCD, around 40% still have the disorder in adulthood, and around 40% qualify for remission.^[217] The risk of having at least one comorbid personality disorder in OCD is 52%, which is the highest among anxiety disorders and greatly impacts its management and prognosis.^[218]