Screen: PHQ-2 → if ≥2, complete PHQ-9

5-9: Watchful waiting, repeat 2-4w

10-14: Moderate - CBT +/− SSRI

15-19: Mod-severe - SSRI + therapy

≥20: Severe - SSRI + referral

First-line: Sertraline 50mg, Escitalopram 10mg

Safety: Ask directly about SI, plan, intent, access. If active → same-day crisis.

≥10: Diagnose GAD. Rule out hyperthyroid, substances, PTSD.

First-line: SSRI/SNRI + CBT. Buspirone adjunct.

Avoid chronic benzos. If needed, ≤2-4w taper.

Panic + agoraphobia → exposure therapy referral.

Never start antidepressant alone if: early onset, postpartum, family history, recurrent depression, antidepressant-induced mania.

MDQ positive → refer psychiatry. Start mood stabilizer, not SSRI.

Red flags: ↓ sleep + ↑ energy, pressured speech, risk-taking.

Disclaimer: Educational tool only. Based on APA, NICE, TMAP, BAP guidelines. Does not replace clinical judgment. Verify dosing, interactions, and monitoring per local formulary. For patients with QTc prolongation, cardiac disease, pregnancy, or treatment resistance, consult psychiatry. In crisis, follow emergency protocols.