lec 5 Flashcards
consequences of drug use
Physical
Direct: Liver, heart & lung damage, increased cancer risk
Indirect: illness, injury, self neglect, harm from risky behaviours (hepatitis, HIV, overdose)
financial
social/interpersonal
consequences of drug use - mental health
Transient psychosis (e.g. cannabis induced psychosis- psychotic symptoms in the moment)
Depression & Anxiety (e.g. depressant effects of alcohol)
For people with established illness (e.g. psychosis, bipolar)
More / worse symptoms, Poorer functioning, More relapses and hospitalisations, Increased suicidality; Aggression
Early interventions for young people with psychosis 90% using cannabis
Prevalence / Epidemiology How common is SUD?
Estimates vary between settings and geographical location (e.g. London versus Rural Wales)
increased availability in cities
UK: Not known how many people with SUD diagnosis
AUD estimate = approx. 600,000 (1%)
UK prevalence - drugs
35% of adults aged 16 to 59 had taken drugs at some point during their lifetime.
1 in 11 (9%) adults aged 16 to 59 had taken an illicit drug in the last year (3.2 million people).
1 in 5 (21%) young adults aged 16 to 24 had taken an illicit drug in the last year; 4.3% classed as ‘frequent” drug users (at least monthly use) clinical definitions may be at least 1-2x per week
Drug use fell 1995-2013 but is now rising again, with a large portion of the increase resulting from increased use of class A drugs in 16-24 year olds
UK prevalence - alcohol
65% of men and 50% of women had drunk alcohol in past week
Prevalence increases with age (up to 75)
38% of men and 19% of women aged 55-64 drinking ‘above safe limits’ (14 units +)
More people ‘never’ drinking increasing and binge drinking (6 units, 2 glasses of wine) decreasing, particularly among young adults
Comorbidity & dual diagnosis
Comorbidity: When two disorders or illnesses occur simultaneously in the same person
Substance use and mental health problems are highly comorbid (occur frequently together)
Dual diagnosis: term used to describe people with both severe mental illness (mainly psychotic disorders) and problematic drug and/or alcohol use - “Dually diagnosed”
Comorbidity rates - just Sz
If you have S, 6-8x more likely to have a drug diagnosis – globally
rates Schizophrenia / psychosis & substance use - drug/smoking
Rates of substance use (drugs, alcohol and tobacco) significantly higher in people with psychosis
50% of people with psychosis use substances; 85% smoke cigarettes
Possible causal role of substances in development of psychosis/ schizophrenia (cannabis
differences between sciz and psychosis
psychosis : a loss of contact with reality that usually includes:
False beliefs about what is taking place or who one is (delusions)
Seeing or hearing things that aren’t there (hallucinations)
Schizophrenia (Sz): Two of: delusions; hallucinations; disorganised speech; disorganised or catatonic behaviour with negative symptoms; with social/occupational dysfunction, lasting 6+ months
Normally think of positive symptoms in diagnosis, but still look at negative (flat affect, etc)
Causes of comorbidity
Substance use causes psychosis
Substance use a consequence of psychosis (self-medication) use drugs to alleviate/cope w symptoms (self-medication hypothesis) select drugs to match specific symptoms e.g., heroine masks symptoms of psychosis
Common origin (e.g. genetic vulnerability) commonality between susceptibility for psychosis and drug use
Bidirectional – psychosis and substance use interact and maintain one another
evidence 1 - Drug use causes psychosis
THC evidence
Evidence that some substances cause transient psychosis
Amphetamine, cocaine and cannabis -induced psychosis
Experimental work with the main psychoactive ingredient of cannabis (THC) - causes psychosis-like symptoms. Those who already have S are more vulnerable to affects of THC
THC produces schizophrenia-like positive symptoms in healthy individuals
THC transiently increases symptoms in people with schizophrenia
Evidence 2 - substance use precedes psychotic symptoms
Swedish
longitudinal prospect studies
Swedish cohort who were in the army
users of cannabis pre18 meant a 6x greater likelihood of hospitalisation for Schizophrenia at age 33
Birth cohort study started in 1970s - Dunedin
Assessed childhood symptoms prior to cannabis (age 11) ; cannabis at 15 & 18; Sz symptoms at 26
Users of cannabis before 15 had more Sz symptoms at 26
Genetic predisposition moderated risk adolescents with COMT polymorphism (Val allele) 10x more likely to have schizophreniform disorder aged 26
Evidence that people with psychosis report using substances to self-medicate
Gregg et al
When I am feeling suspicious or paranoid: 57%
When I am hearing sounds or voices that other people can’t hear: 60%
When I am experiencing medication side effects: 39%
Evidence that genetic factors may predispose individuals to both mental illness and substance use
Adolescents with COMT polymorphism (Val allele)10x more likely to have schizophreniform disorder at age 26
Substance use may precipitate psychosis i.e. may cause psychosis in people who would have developed it anyway (more susceptible to psychotogenic effects)
