Evidence-based screening tools enable early identification of substance use disorders in all clinical settings. The SBIRT (Screening, Brief Intervention, and Referral to Treatment) framework is the overarching evidence-based model: universal screening → brief motivational intervention for at-risk individuals → referral to specialty treatment for those meeting SUD criteria. CAGE questionnaire (alcohol): 4 binary questions — (C)ut down: felt need to cut down drinking? (A)nnoyed: annoyed by criticism of drinking? (G)uilty: felt guilty about drinking? (E)ye-opener: needed a morning drink? Scoring: ≥2 positive = sensitivity 93%, specificity 76% for alcohol dependence. Limitation: better at detecting dependence than hazardous drinking; not validated for drug use. AUDIT (Alcohol Use Disorders Identification Test — WHO): 10 items scored 0-40 covering consumption (items 1-3), dependence (items 4-6), and consequences (items 7-10). Scoring: 0-7 = low risk, 8-15 = hazardous drinking (brief intervention), 16-19 = harmful use (brief intervention + monitoring), ≥20 = likely dependence (referral to treatment). AUDIT-C is a 3-item abbreviated version (items 1-3 only) used for quick screening: ≥4 for men, ≥3 for women suggests hazardous drinking. DAST-10 (Drug Abuse Screening Test): 10...