Substance-induced mood and anxiety — timing, alcohol and dual care (MEQ)

(i) Definition and discriminators. Substance/medication-induced depressive disorder is a prominent depressed mood and/or anhedonia developing during or soon after intoxication, withdrawal or a culprit medication capable of producing the symptoms, not better explained by independent depression, not exclusively during delirium, and causing distress/impairment. Discriminators: delirium shows fluctuating attention and medical instability; independent MDD is favoured by offline episodes, family history of mood disorder, and persistence substantially beyond the expected abstinence window. Here, symptoms track heavy drinking with prior sober periods free of depression — favours induced, still provisional.^[1]

(ii) Assessment and investigations. Rebuild timeline (10 years heavy use, 4 weeks depressive syndrome while drinking, prior sober periods without MDD), collateral, MSE, explicit suicide risk (ideation, intent, plan, means, protective factors), capacity/legal status under local principles (no invented section numbers), and AUD criteria. Investigations: observations/CIWA ongoing; FBC, U&E, LFT, glucose, TFT as indicated, pregnancy test if applicable; UDS if other substances suspected; ECG before some antidepressants. Thiamine already given — continue Wernicke prevention per protocol.^[1][2]

(iii) Dual management. Medical detox and suicide safety first. Disease-modifying core: abstinence support with MI/CBT and AUD pharmacotherapy — example naltrexone 50 mg oral daily if opioid-free (LFT counselling; opioid analgesia blocked). For depression: watchful waiting ~2–4 weeks of abstinence is reasonable if risk is contained and history strongly suggests pure induced depression (Brown/Schuckit early remission curve). Start antidepressant earlier if severity/suicide risk escalates or independent features emerge — example sertraline 50 mg oral daily, titrate as tolerated, review risk and side-effects early. Pettinati-style dual thinking: treat both axes (sertraline + naltrexone in selected patients). Integrated concurrent care, not sequential exclusion; written crisis plan; early follow-up.^[2][3][4][5]

(iv) Prognosis counselling. Many alcohol-related depressive symptoms improve substantially with sustained abstinence (Brown & Schuckit). Independent MDD remains possible and would need full mood care. Dual prognosis worsens with ongoing drinking; treating both axes improves outcomes framing. Name Nunes/Levin modest antidepressant benefit when depression is carefully diagnosed; name Pettinati combination signal for drinking outcomes. Reassess diagnosis at 2–4 weeks and after sustained abstinence.^[2][3][4]