This DSM-5-TR chapter groups disorders characterized by repetitive thoughts or behaviors that the person feels driven to perform. They were separated from anxiety disorders in DSM-5, although anxiety is often prominent.

Core concepts

• Obsessions: recurrent, intrusive, unwanted thoughts, urges, or images that cause marked anxiety or distress (e.g., contamination, harm, doubt, symmetry, taboo thoughts). The person tries to ignore, suppress, or neutralize them
• Compulsions: repetitive behaviors (washing, checking, ordering) or mental acts (counting, praying, repeating words) performed to reduce the distress caused by obsessions or to prevent a feared event. They give short-term relief but maintain the disorder through negative reinforcement
• Symptoms are time-consuming (more than 1 hour a day) or cause significant distress or impairment

Neurobiology — dysfunction of the cortico-striato-thalamo-cortical (frontal–striatal–thalamic) circuit, involving the orbitofrontal cortex, anterior cingulate, and caudate; serotonin dysregulation (the basis for SSRI response), with glutamate and dopamine contributions. Genetic factors are significant. Childhood-onset cases can follow streptococcal or other infections (PANS/PANDAS) in a subset.

Disorders in this chapter

Tooth grinding (bruxism) is not a disorder in this chapter; sleep-related bruxism is classified with sleep-related movement conditions.

Distinguish from obsessive-compulsive personality disorder (OCPD) — a pervasive pattern of perfectionism, rigidity, and control that the person usually sees as appropriate (ego-syntonic), without true obsessions and compulsions. OCD symptoms are typically ego-dystonic (recognized as excessive).

• Content, frequency, and triggers of obsessions; type of rituals; time spent daily; degree of distress and interference with work, school, relationships, and self-care (key measures of severity)
• Insight level; avoidance patterns; family accommodation (relatives participating in rituals)
• Physical consequences: chapped, cracked, bleeding, or infected hands from washing; skin lesions and infection from picking; alopecia, and trichobezoar (hair ball causing GI obstruction) if hair is swallowed; falls, fire hazards, pests, and poor sanitation in hoarding
• Depression and suicide risk (especially BDD), tics, substance use, eating disorders
• Older adults who hoard: self-neglect, fall and fire risk, possible cognitive impairment

Psychotherapy — first-line

• Exposure and response prevention (ERP): graded exposure to the feared trigger (e.g., touching a "contaminated" object) while resisting or delaying the compulsion; anxiety rises, then declines without the ritual, and the client learns the feared outcome does not occur
• CBT with cognitive restructuring (inflated responsibility, overestimation of threat, need for certainty)
• Habit reversal training for trichotillomania and excoriation disorder: awareness training, competing response (e.g., clenching fists, holding a stress ball), and social support; stimulus control (gloves, covering mirrors, keeping nails short)
• CBT for hoarding: motivation enhancement, sorting and decision-making skills, gradual discarding practice, reduced acquiring — done collaboratively with the client
• CBT for BDD: exposure, reducing mirror checking and camouflage, perceptual retraining

Medications

Procedures for severe refractory OCD: deep transcranial magnetic stimulation (FDA-cleared for OCD) and, in specialized centers, deep brain stimulation.

Listed in priority order.

1. Physical safety and basic needs
   • Treat skin damage from washing or picking (gentle cleansers, emollients, wound care, infection monitoring)
   • Ensure nutrition, hydration, sleep, and hygiene are not displaced by rituals
   • Assess suicide risk, particularly in BDD and with comorbid depression
2. Do not abruptly block rituals — forcibly stopping a compulsion causes severe anxiety. Early in care, allow time for rituals within a structured daily schedule, then gradually limit them in agreement with the client and the treatment plan
3. Support ERP as planned by the team — encourage graded exposure and delaying the ritual; praise effort; do not physically restrain the client from rituals or use punishment
4. Therapeutic communication
   • Acknowledge the distress ("You seem very worried that someone could get in"), explore feelings, and help identify triggers
   • Avoid arguing about the logic of obsessions or giving repeated reassurance ("That's not true, don't worry") — reassurance acts like a compulsion and keeps the cycle going
   • Explore coping alternatives together
5. BDD — validate the distress without confirming or debating the perceived flaw; explore thoughts and feelings; support CBT and discourage repeated cosmetic procedures
6. Hoarding
   • Priority is safety (fire exits, falls, sanitation) — assess the home with the client and negotiate small, concrete changes first
   • Never discard items without consent or organize forced clean-outs; they damage trust and are followed by rapid re-accumulation
   • Coordinate with community services (adult protective services, housing, fire safety) when there is serious risk
7. Hair pulling and skin picking — identify antecedent situations and emotions (boredom, stress, perfectionism), teach competing responses, keep hands busy, and provide wound care

• OCD is a medical condition linked to brain circuits — not a character flaw; effective treatment exists
• ERP works by facing fears without performing rituals; anxiety drops with practice
• SSRIs need 8–12 weeks at an adequate dose to reduce OCD symptoms and often need higher doses; do not stop suddenly; report worsening mood or suicidal thoughts
• Clomipramine: rise slowly (dizziness), manage dry mouth and constipation, avoid alcohol, report palpitations or seizures, store safely
• Family: reduce accommodation (joining rituals, giving constant reassurance) gradually and supportively; avoid criticism
• Hoarding: set small, achievable goals (one area, one category at a time)
• Skin and hair: keep nails short, use gloves or bandages as barriers, moisturize after necessary handwashing

• Compulsions reduce the anxiety caused by obsessions — relief reinforces the cycle
• Severity = time consumed (more than 1 hour/day) and interference with daily functioning
• ERP = graded exposure + resisting/delaying the ritual — the key psychotherapy
• SSRIs first-line; higher doses and 8–12-week trials; clomipramine is an alternative (seizures, cardiac toxicity)
• Circuit: frontal–striatal–thalamic dysfunction; serotonin
• Do not abruptly stop rituals early in care; schedule and gradually limit
• Avoid arguing and repeated reassurance; acknowledge feelings
• BDD: perceived flaw not observable to others; high suicide risk; cosmetic surgery does not help
• Hoarding: never discard without consent; safety first, small negotiated steps
• Trichotillomania and excoriation → habit reversal training
• OCD is ego-dystonic; OCPD is ego-syntonic perfectionism without true rituals