Substance-Related and Addictive Disorders — General Principles

1. Overview & Epidemiology

Core terminology (Kaplan & Sadock). DSM-5/5-TR collapsed the old DSM-IV split of abuse + dependence into one spectrum, substance use disorder (SUD), graded mild/moderate/severe. The older terms still appear in the Hungarian oral exam and in ICD-10, so know them:

• Abuse — chronic, maladaptive self-administration deviating from approved social/medical patterns, causing impairment or distress (failed role obligations, hazardous use, legal problems, interpersonal problems). It does not require tolerance or withdrawal.
• Dependence — pattern of compulsive use defined by ≥3 areas of impairment within 12 months. Subdivided into:
  • Physical (physiological) dependence = an altered physiological state from repeated use, so that cessation triggers a specific withdrawal syndrome. Tolerance + withdrawal are its markers. (This is the answer to 4.18: benzodiazepines, opiates and alcohol can all produce physical dependence.)
  • Psychological (behavioural) dependence = craving, drug-seeking, and dominance of substance-related activities over normal life, with or without physical signs.
• Tolerance — a given dose produces a decreased effect, or larger doses are needed for the original effect.
• Cross-tolerance / cross-dependence — one drug substitutes for another in the same class (e.g. benzodiazepines ↔ barbiturates ↔ alcohol). This underlies benzodiazepine treatment of alcohol withdrawal.
• Intoxication — a reversible substance-specific syndrome affecting memory, orientation, mood, judgement and behaviour.
• Withdrawal (abstinence syndrome) — substance-specific syndrome after stopping/reducing prolonged regular use; physiological signs plus disturbed thinking, feeling and behaviour.
• Misuse — improper use of a prescribed drug. Co-dependence / enabler — family members who sustain the addictive behaviour.

Designer ("synthetic") drugs (4.19). Beyond classical drugs, synthetic amphetamines, synthetic opioids and synthetic cannabinoids ("designer drugs") are increasingly used. Standard urine drug screens usually cannot detect them, their legal regulation lags behind, and — critically — their pathomechanism and adverse effects are largely unknown. This is a major emergency-room problem in Hungary/Europe.

Scale of the problem (Kaplan). Comorbid psychiatric diagnosis occurs in ~60–75% of patients with substance-related disorders (dual diagnosis). Substance-induced syndromes can mimic the full range of mood, psychotic and anxiety disorders, so SUD must always sit in the differential. The 11 DSM substance classes: alcohol; amphetamine-type stimulants; caffeine; cannabis; cocaine; hallucinogens; inhalants; nicotine/tobacco; opioids; phencyclidine (PCP); and sedatives/hypnotics/anxiolytics (+ a residual "other" class, e.g. anabolic steroids, nitrous oxide).

---