Definition & diagnostic considerations

Substance/medication‑induced obsessive‑compulsive and related disorder is diagnosed when prominent OCD symptoms develop during or soon after exposure to a substance or medication, and when the symptoms are in excess of what would be expected from intoxication or withdrawal alone. Document temporal relationship and rule out primary OCD that predates exposure.

Common offending agents

• Stimulants: amphetamines, cocaine, methylphenidate — may precipitate repetitive thoughts/behaviours during intoxication or early abstinence.
• Serotonergic agents: abrupt SSRI initiation or dose changes can rarely provoke activation or emergence of obsessive phenomena in susceptible individuals.
• Corticosteroids and other neuroactive medications: high‑dose steroids have been associated with a range of psychiatric symptoms including obsessions or compulsive behaviours.
• Hallucinogens or cannabis: in some individuals, these can trigger intrusive or ruminative thoughts that resemble obsessions.
• Alcohol and benzodiazepine withdrawal: rebound anxiety and repetitive checking behaviours may occur during withdrawal phases.

Clinical presentation

• New‑onset obsessions (intrusive, distressing thoughts) or compulsions (repetitive rituals) temporally linked to substance use/medication changes.
• Symptoms may be confused with substance‑related anxiety, akathisia, or psychosis—careful phenomenological assessment needed.
• Severity ranges from mild, transient symptoms during intoxication/withdrawal to persistent, treatment‑resistant OCD that continues after cessation of the agent.

Assessment checklist

1. Obtain detailed timeline: substance/medication start, dose changes, last use, and onset/course of OCD symptoms.
2. Screen for intoxication, withdrawal signs, akathisia, psychosis, mood disorders and medical causes (thyroid, infection, metabolic disturbances).
3. Use collateral information (family, pharmacy records) and consider urine/toxicology screening when accuracy of exposure history is uncertain.
4. Assess severity and functional impact, suicidality, and risk behaviours associated with compulsions (e.g., excessive cleaning causing skin breakdown).

Differential diagnosis

• Primary OCD (pre‑existing obsessive‑compulsive disorder), substance‑induced anxiety or psychotic symptoms, akathisia (restlessness mistaken for compulsive urges), and mood disorders with ruminative thoughts.
• Consider pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS) in children with abrupt onset of OCD symptoms.

Management principles

1. Address the offending agent: where safe and feasible, reduce dose or discontinue the implicated substance/medication in consultation with treating teams; manage withdrawal risks (e.g., benzodiazepine taper, stimulant cessation support).
2. Supportive management: psychoeducation, sleep and anxiety management, and treat comorbid substance use disorder with appropriate psychosocial and pharmacologic interventions (e.g., opioid agonist therapy, alcohol treatment).
3. Standard OCD treatments: CBT with exposure and response prevention (ERP) is first‑line; SSRIs at OCD‑effective doses may be used when OCD symptoms persist after resolving substance effects—coordinate carefully if agent is serotonergic.
4. Specialist involvement: refer to addiction psychiatry and OCD specialists for complex cases, severe persistent symptoms or when iatrogenic causes (steroid, SSRI) are suspected and require nuanced management.

Pharmacologic considerations

• Avoid automatically prescribing high‑dose SSRIs while intoxicated—prioritise stabilisation and reassessment after cessation. If SSRIs are indicated, start at appropriate doses for OCD and monitor for activation.
• When symptoms are severe and immediate relief needed, short‑term adjunctive antipsychotics may be considered in specialist settings, although evidence is limited and risks must be weighed.
• Treat withdrawal syndromes (e.g., benzodiazepine taper) under supervision to reduce rebound anxiety and symptom persistence.

Practical tips for clinicians

• Always map a timeline between substance/medication exposure and symptom onset; involve prescribing clinicians before stopping essential medications (steroids, psychotropics).
• Use brief assessment tools for OCD severity (Y‑BOCS) and addiction severity; arrange pharmacy checks and toxicology as needed to confirm exposures.
• Coordinate care between addiction services, prescribing teams and CBT/ERP therapists for integrated management and follow‑up.