Transcript Epidemiology of addictive disorders

Epidemiology of addictive disorders:
a brief review
MRCPsych addiction psychiatry seminar
series
Dr Stuart McLaren
2nd March 2012
Epidemiology of substance use
consumption
/use
dependence
problems/harms
Prevalence of psychiatric disorders,
% adult population
Common mental disorders
Psychosis
Alcohol dependence
Drug
16.2
0.4
5.9
9.2
APMS 2007
Lifetime prevalence of drug use, %
of adult population
Overall
Cannabis
Amphetamines
Cocaine
Ecstasy
Opiates
35.5
30
12
7.7
7.3
<1
2006/2007 BCS
Prevalence rate of heroin and crack
cocaine users in England per 1000
population aged 15 to 64 by gender
Male
Female
Rate
15.32
4.64
95% CI
14.86-15.87
4.61-4.99
Hay et al. 2007
Prevalence of drug dependence, %
adult population
All
3.4
Cannabis only 2.5
Other drugs
0.9
2007 APMS
Prevalence of injecting in England
per 1000 population aged 15 to 64
Rate
3.01
95% CI
2.92-3.14
2009/10 NDEC
Main drug in adult treatment
populations (n=174250)
Heroin
Crack
Cocaine
Methadone
Cannabis
66%
6%
6%
8%
7%
NDTMS 2007/8
Illicit drug trends
•
•
•
•
•
•
Drug dependence stable since 2000
Increasing multiple drug use
Opiate use stable, may be falling in young
Use of opiates correlates with deprivation
Cannabis use may be falling
Use greater in lower income groups
Psychiatric co-morbidity
70% of opiate users have another current
psychiatric disorder
Drug dependency strongly associated with:
•
ASPD
•
BPD
2007 APMS
Substance related harms and risks
‘with drugs nothing is always. Their
use does not carry a guarantee of
danger, but neither is their safety
guaranteed. What one needs to ask
about any substance is not whether in
absolute terms it is safe, but rather the
degree of risk which may attach to its
use.’
Health consequences of drug use
• Acute toxic effects, including overdose
• Acute intoxication effects, including
accidental injury and violence
• Dependence
• Adverse health effects of chronic, regular
use, including chronic disease, BBVs and
mental disorder
Risky periods for opiate users
Risk increases during periods of transition:
• Release form prison (SMR ~8)
• Early in substitute treatment (x3 increase
compared with later treatment)
• Following discharge from methadone
maintenance treatment (MRR ~10 in first 2
weeks)
Epidemiology of drinking and alcohol-related
harm
consumption
/use
dependence
problems/harms
Consumption and risk –
units/week
Men
<21
Women
<14
Hazardous
drinking
22-50
15-35
Harmful drinking
>50
>35
Low risk
Prevalence of hazardous and harmful
drinking, % adult population
hazardous
AUDIT score
M
F
All
8 or more
38
15
25
harmful
16 or more
6
2
3.8
APMS 2007
Prevalence of alcohol dependence in
last 6/12 - % of adult population
Mild
Moderate
Severe
Overall
M
F
All
7.8
0.8
0.1
8.7
3.2
0
0
3.3
5.4
0.4
0.1
5.9
2007 APMS
Psychiatric co-morbidity
37% of those with alcohol use disorders have
another mental disorder
Alcohol dependence is
• strongly associated with ASPD
• moderately associated with BPD and drug
dependence
2007 APMS
Alcohol trends
• CAGE scores increasing between
generations of men
• Dependence and hazardous drinking peak in
middle occupations
• Heavy drinking shows no clear class
gradient
• Younger people and women at particular
risk
1. Risk factors for drug use
• Social factors
– Availability
– Early use of tobacco and alcohol
– Disadvantaged background
• Family factors
– Poor parent-child relationships
– Parental conflict
– Parental dug use
2. Risk factors for drug use
Individual factors:
• male
• novelty seeking personality
• early conduct disorder
• poor school performance/early school leaving
Affiliation with antisocial and drug-using peers
Above factors often co-occur
Risk factors for drug dependency
• Early onset of drug use
• Multiple drug use
• Mental health disorders before the age of 15
years (conduct disorder and depression)
Addiction careers
‘the period in which substance use causes
problems’
Lifetime use (%)
Lifetime
dependence (%)
Capture rate
Tobacco
76
24
32
Heroin
1.5
0.4
24
Alcohol
92
14
15
Clinical course of alcohol
dependence
Age of:
• First drink*
• First intoxication*
• First problem*
• Onset of dependence
• Age of death
13-15 years
15-17 years
16-22 years
25-40 years
60 years
* Same as general population