Substance abuse

Question 1

Define

Answer 1

Substance misuse = a pattern of substance use causing physical, mental, social, or occupational dysfunction

• CD-10 define substance use disorders according to (1) the substance, and (2) the type of disorder:
• Acute intoxication – transient state of emotional & behavioural change after psychoactive substance (PS) use
• Dose dependent
  Time limited N.B. physical withdrawal only occurs from: ETOH, opiates, BDZ
• Harmful use – a pattern of use likely to cause physical or psychological damage
• Dependency – a cluster of physiological, behavioural and cognitive symptoms in which the use of a substance takes on a much higher priority than other behaviours that once had a greater value (ICD-10)
• Withdrawal – transient state occurring while re-adjusting to lower levels of a drug in the body
• Psychotic disorder – psychotic symptoms occurring during or immediately after PS use, characterised by vivid hallucinations, abnormal affect, psychomotor disturbances, persecutory delusions and delusions of reference
• Amnesic disorder – memory and other cognitive impairments caused by substance use (i.e. Wernicke’s)
• Residual and late onset psychotic disorders – where effects on behaviour, affect, personality or cognition lasting beyond the period during which direct PS effect might be expected

Question 2

Epidemiology

Answer 2

More common in men than women
- 2: 1 alcohol disorders 5.4% lifetime prevalence
- 4: 1 substance misuse disorders 14.6% lifetime prevalence (drug dependence = 3.0%)

The UK recommends 14 units/ week as a safe amount of alcohol to consume in both men and women

1 unit of alcohol is:
- 10ml or 8g or pure ethanol
- Amount of alcohol that an adult can metabolise in 1 hour
- 25ml of 40% proof ethanol
- 1 unit of alcohol= (total volume (ml) x y% of alcohol by volume)/ 1000

 

Question 3

Outline dependence theories

Answer 3

Dependence theories:

Learning theory

Classical conditioning – association (i.e. seeing a needle -> craving heroin)

Operant conditioning – rewarding behaviours are repeated (i.e. drug provide pleasure) and behaviours that relieve unpleasant experiences are repeated

Social learning theory – we copy behaviour of others (i.e. Vietnam Heroin use)

Neurological theories Activation of dopaminergic reward centres:
- Block DA re-uptake – cocaine, amphetamines ·
- Increase DA and other NTs – alcohol, opiates Blunted reward system deficiency

Question 4

Characteristics of dependence

Answer 4

Features of dependency (ICD-10) – dependence syndrome = ≥3 of the below together at some point in last month

• Tolerance
• Craving
• Withdrawal
• Problems controlling use
• Continued use despite harm
• Salience / primacy
• Reinstatement
• Narrowing repertoire