PSYX 340 Psychological Disorders · Unit 2: Mood, suicide, body and addiction · on Exam 2
2.6 Substance use and addictive disorders
Study notes for Substance use and addictive disorders in PSYX 340 Psychological Disorders at Montana State University: the big ideas, a worked example, common mistakes and an exam tip. The same topic has endless practice questions and flashcards in Mathub.
Big ideas
- DSM-5-TR uses one substance use disorder with 11 possible criteria in four groups (impaired control, social impairment, risky use, and pharmacological criteria: tolerance and withdrawal). Severity: mild 2–3 criteria, moderate 4–5, severe 6 or more, within a 12-month period.
- Depressants slow the central nervous system: alcohol (increases GABA effects; long-term heavy use can cause Korsakoff’s syndrome from thiamine deficiency, and fetal alcohol syndrome in pregnancy), sedative-hypnotics (benzodiazepines) and opioids (bind endorphin receptors; overdose slows breathing and is reversed by naloxone).
- Stimulants (cocaine, amphetamines, caffeine, nicotine) increase dopamine and norepinephrine activity. Hallucinogens (LSD, psilocybin) alter perception. Cannabis acts on cannabinoid receptors; THC potency has risen sharply over recent decades.
- Causes: the brain’s reward pathway (dopamine, nucleus accumbens) and reward-deficiency ideas, genetics, tolerance-producing brain changes, operant and classical conditioning, expectancies, and sociocultural factors such as stress, poverty and family use.
- Treatment: detoxification; agonist substitution (methadone or buprenorphine for opioids), antagonists (naltrexone) and aversion therapy; CBT and relapse prevention; contingency management; motivational interviewing; self-help groups (AA). Gambling disorder is the only non-substance addictive disorder in the DSM; internet gaming disorder is listed as a condition for further study.
Worked example
In the past year Sam has drunk more than intended, tried and failed to cut down, missed classes after drinking, and needs more alcohol to feel an effect. How many criteria and what severity?
Show the solution
Four criteria: using more than intended, unsuccessful efforts to cut down, failing obligations (missed classes) and tolerance. Four or five criteria is moderate alcohol use disorder.
Common mistakes
- Counting tolerance and withdrawal from prescribed medication taken as directed. They do not count toward the disorder in that case.
- Mixing up agonists (methadone, buprenorphine: activate the same receptors more safely) and antagonists (naltrexone: block them).
- Calling alcohol a stimulant because people act livelier. It is a depressant that lowers inhibition.
Exam tipMemorize the severity cutoffs (2–3, 4–5, 6+) and practise counting criteria in a vignette. Also expect drug-to-class and drug-to-neurotransmitter matching.
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