FFinalistSouthampton · 2027
Psychiatry
AKT · Psychiatry/Substance & behavioural

Substance use disorder

Overview

A problematic pattern of substance use causing clinically significant impairment — features of dependence: tolerance, withdrawal, compulsion, loss of control, salience, persistence despite harm.

Recognise

  • Tolerance and withdrawal
  • Strong desire/compulsion to use; difficulty controlling use
  • Neglect of alternatives, persistence despite harm

Red flags

  • Overdose risk, injecting-related harm (BBV, sepsis), risk to dependents

Differentials & how to tell them apart

Harmful use without dependenceno tolerance/withdrawal/compulsion
Primary mental illness with secondary usedual diagnosis — treat both

Investigations

History, urine drug screen, BBV screening (HIV, hepatitis B/C), assess physical/social harm.

Management

  1. 1Psychosocial intervention + harm reduction (needle exchange, BBV vaccination/testing, naloxone).
  2. 2Substance-specific pharmacotherapy (substitution or relapse prevention) via specialist drug services.
Opioid substitution (methadone/buprenorphine) — opioid dependence
Naltrexone/acamprosate/disulfiram — alcohol
Nicotine replacement / varenicline / bupropion — tobacco

Key points

Address dual diagnosis; safeguarding of dependents.

Monitor & prognosis

Use, engagement, BBV status, physical and social harm.

Relapsing-remitting; outcomes improve with retention in treatment.

Source: NICE CG51/115; StatPearls