Psychology for medicine - substance misuse

• Use of all illicit drugs.
• Use of prescribed drugs for non-medical purposes.
• Use of a drug in particular contexts (eg drinking and driving).

Valium & other benzos (eg to come down from ecstasy; to prolong heroin’s effects)
Viagra (when not prescribed)
ketamine
opiate pain killers

1.Apatternofsubstanceuseleadingtosignificant impairment or distress.
• 2.Includesrecurrentuseleadingtoatleastoneof: failure to fulfill important obligations; physical hazards; repeated legal problems;continued use despite social/interpersonal problems

1.Apatternofsubstanceuseleadingtosignificant impairment or distress.
• 2.Includesatleast3of: tolerance; withdrawal; taking more, for longer than intended; lack of success in controlling use; much time devoted to finding & using; priority of substance over other activities despite problems caused

reduced effect of drug after repeated administration OR increased dose of drug to maintain same effect.

signs & symptoms observed when a previously used drug is reduced in dose or stopped.

Tobacco, Alcohol, Other( opiates,
cannabis, amphetamines, ecstasy
hallucinogens eg LSD, solvents,
cocaine/crack, benzodiazepines, ketamine, steroids, ‘mushrooms’.

Rates of alcohol abuse:
- higher in poorer areas.
- increase with unemployment rates.
- lower in some cultural groups (eg Jewish) than others (e.g. Irish & Russian men)

Classical conditioning: cues associated with drug (eg smell or sight of alcohol; drinking friends; the local pub) become conditioned stimuli.

Operant conditioning: the drug is a reward and rewarded behaviour (drug taking) is repeated.

Addicts show impairments on tasks of decision making & planning.
They also have higher impulsivity & do poorly on tasks of behaviour
inhibition.
Memory – especially working memory – is also impaired.
As the individual becomes addicted, the drug grabs their attention so it becomes more important than natural rewards. So many stimuli (e.g. needles, smells) and other factors (e.g. stress) elicit cravings for drugs.
Cognitive therapy involves recording thoughts and cravings with the aim of breaking the links between them.

A cycle: Precontemplation > contemplation >determination > action > maintenance > precontemplation.

Treat by Motivational Interviewing

Drugs hijack the brain’s natural reward pathway – the mesolimbic
dopamine system (Robinson & Berridge, 2003)

Cocaine & amphetamine exert primary effects on dopamine; many other drugs act indirectly to facilitate dopamine release.

Cocaine & amphetamine exert primary effects on dopamine; many other drugs act indirectly to facilitate dopamine release.DA D2 receptors particularly implicated in addiction.

Cocaine abusers have lower D2 receptor density in striatum

Those with high density did not like the effects of a stimulant drug.

Those with low density did like its effects.

Reduced glucose metabolism in frontal cortex

Loss of prefrontal cortical volume

Cognitive impairment - Poor inhibitory control - Poor decision making & planning - Memory impairment

Replacers - eg methadone; nicotine patches
Sensitizers - eg disulfiram (Antabuse)
Blockers - eg opiate antagonists like naltrexone.

20 monkeys – individually housed for 1.5 years. PET scanned.
Then assigned to social groups of 4.
Over 3 months, one in each group became dominant. All PET scanned again.

Replacers - eg methadone; nicotine patches
Sensitizers - eg disulfiram (Antabuse)
Blockers - eg opiate antagonists like naltrexone.

20 monkeys – individually housed for 1.5 years. PET scanned.
Then assigned to social groups of 4.
Over 3 months, one in each group became dominant. All PET scanned again.

Drug dependence involves biological, cognitive, motivational, behavioural & social components.

Treatment can best address all these components – the biopsychosocial view.

Only around 20% of people with substance abuse/dependence problems enter treatment.

decrease by 30%

Drug dependence involves biological, cognitive, motivational, behavioural & social components.

Treatment can best address all these components – the biopsychosocial view.

Only around 20% of people with substance abuse/dependence problems enter treatment.

decrease by 30%

every 1 pound spend is 3 pounds saved