| Drug | Class | Adult | Paediatric | Notes |
|---|---|---|---|---|
| Sertraline[1] | SSRI | 50 mg PO daily start, titrate to 100–200 mg/day; review at 2–4 weeks | — | First-line SSRI in adults; activating, weight-neutral; counsel about initial activation and suicide warning <25 years; full effect 4–6 weeks |
| Escitalopram[1] | SSRI | 10 mg PO daily start, titrate to 10–20 mg/day | — | Alternative first-line; QTc warning at higher doses; check baseline ECG in cardiac comorbidity |
| Mirtazapine[1] | Tetracyclic antidepressant — α2 antagonist + 5-HT2 + 5-HT3 blocker | 15 mg PO night start, titrate to 30–45 mg night | — | Useful with insomnia, weight loss, comorbid anxiety; sedating at lower doses; weight gain; less sexual dysfunction than SSRIs |
| Venlafaxine extended-release[1] | SNRI | 75 mg PO daily start, titrate to 150–225 mg/day | — | Second-line if SSRI inadequate; monitor BP at higher doses; discontinuation syndrome — taper |
| Lithium (augmentation)[1] | Mood stabiliser | Start 400 mg PO daily, titrate to plasma 0.4–0.8 mmol/L (0.6–1.0 in mania) | — | Augmentation in treatment-resistant depression; renal and thyroid function monitoring; narrow therapeutic index — drug interactions matter; teratogen |
| Esketamine (intranasal) — TRD[1] | NMDA receptor antagonist | 56–84 mg intranasally with concurrent oral antidepressant; specialist-supervised in clinic with 2 h post-administration monitoring | — | Treatment-resistant depression; effects within hours; specialist setting with monitoring; dissociation, hypertension, abuse potential |
| Olanzapine + fluoxetine combination (TRD or psychotic depression)[1] | Atypical antipsychotic + SSRI | Olanzapine 5–10 mg PO + fluoxetine 20–40 mg PO daily | — | Treatment-resistant or psychotic depression; metabolic monitoring; sedation; FDA OFC fixed-dose combination available |
Stepped-care diagnosis and management of depression in adults — psychological therapies, pharmacotherapy, and treatment-resistant depression.