Download The relationship between substance use disorders, mental illness

Mental illness, substance use disorder,
and violent offending
Challenge of dual diagnosis: Current perspectives
North West Forensic Academic Network
Manchester, U.K., 24 November, 2005.
Martin Grann
Centre for Violence Prevention
Karolinska Institute
Stockholm, Sweden
Dual diagnosis: The relationship between substance
use disorders, mental illness, and violent crime
Mental illness
”Dual Diagnosis”
A
Substance use
Violent crime
B
MENTAL ILLNESS AND VIOLENCE
Are the mentally disordered
more dangerous than others?
(Is the public fear of
psychiatric patients
warranted?)
Mental illness
?
Violence
 A violent
act
 A mental
illness
 A causal
link between illness and act of violece
Mental illness
?
Violence
These assumptions are fundamental to...
Mens rea, culpability, medico-legal insanity;
differentiated sanctions

(NGRI, NCRAMD, fitness to plead; ”fängelseförbud” etc)
 Indeterminate institutionalisations - dangerousness
(Dangerous Offenders Act, preventative detention, DSPD, "Särskilda
skyddsreaktioner” etc)
SUPPORT FOR and AGAINST
AN ALLGED ASSOCIATION BETWEEN
MENTAL ILLNESS & VIOLENCE (1)
• From Plato to Hollywood…
• The mythology of the mad serial killer
• High-profile cases
SUPPORT FOR and AGAINST
AN ALLGED ASSOCIATION BETWEEN
MENTAL ILLNESS & VIOLENCE (2)
Empirical investigations:
• Increased prevalence rates of mental
disorder amongst prisoners convicted of
violent offences
• Violence by people with mental disorder
• Cohort studies
Prevalence of mental
disorders in prisoners
• Homicide 50-90% mentally
disordered, of which 5-20%
psychoses
(Erb et al 2001; Fazel & Grann 2004;
Gottlieb, Gabrielsen & Kramp 1987;
Shaw Appleby & Amos 1999)
• Prison: One in three prison
inmates suffer from serious
mental illness
(Abrams & Teplin 1991, Blaauw 2002)
• Recent meta-analysis
suggested 4% psychoses,
12% depression, and 46%
antisocial PD in prisons
(Fazel & Danesh 2002)
• Among defendants referred for
forensic evaluation by courts
in Sweden: approx. 40%
psychosis, concomitant PD
60% and substance use
disorder 55% of the cases
(Official statistics, RMV)
Violence in mentally disordered
• Individuals suffering from
schizophrenia; higher risk
than general population to
commit violent offence
(Lindqvist & Allebeck 1990, and a
large number of others)
• Major mental disorder (incl.
schz, major depression and
bipolar syndrome) 2-6 times
higher risk than healthy
controls
(Brennan 1996; Eronen et al 1996)
• 12% of general psychiatric • An association with
inpatients commit violent
deinstitutionalisation?
acts during the first year
(Mullen et al 2000; 2004)
after discharge
(Walsh et al 2001; Monahan et al
2001)
Mental Illness
?
Violence
INTERPRETATION?
• ” Weak association, does not warrant current
legislations ”
• ” A robust association, but accounted for primarily by
concomitant substance use and SES factors ”
• ” A strong association – and one that is explained by
the illness per se, i.e. ’illness drives violence’ ”
IS THE GLASS
HALF-FULL or HALF-EMPTY?
DEBATE
Age- and sex-adjusted relative risk of 4
to 6 times higher to offend violently
compared with general population
Approx. 90% of mentally ill do not
offend violently
POPULATION IMPACT
Population attributable
risk (PAR)
Population attributable
risk fraction (PAF)
THE CONTRIBUTION OF MENTAL
DISORDER TO VIOLENT CRIME
Martin Grann, PhD CPsych, Associate Prof. 1) Honorary Research Fellow 2)
Seena Fazel, MB ChB MD MRCPsych, Senior Research Fellow 2) , Research affiliate 1)
1) Karolinska Institute
Centre for Violence Prevention
Stockholm, Sweden
2) Oxford University
Dept. of Psychiatry
Oxford, U.K.
Population attributable risk
DEFINITIONS
Individuals:
T
C
CMCM+
M
T
No of people in the population
M
No of people hospitalised with psych.
diagnosis
C
No of people convicted of at least
one violent crime
CM-
People without psych hospitalisations
who were convicted
CM+
People with psych hospitalisations
who were convicted
DEFINITIONS (contd.)
No of violent convictions:
T
C
No of violent convictions of people
without psych. admissions
NCM+
No of violent convictions of people
with psych. admissions
CMCM+
M
NCM-
NC
No of violent convictions
NC
= NCM- + NCM+
DEFINITIONS (contd.)
is the rate of violent crimes per 1000 persons in the population
r = NC
T
r0 = NCM- is the rate of violent crimes per 1000 non-disordered persons
T-M
r1 = NCM+ is the rate of violent crimes per 1000 mentally disordered persons
M
RR = r1/ r0
RD = r1- r0
RD% = (r1- r0) / r1
is the rate ratio
is the rate difference (in rate per 1000)
is the rate difference percent (%)
DEFINITIONS (contd.)
Population attributable risk
PAR = r-r0 = NC - NCMT
T-M
[ ][
]
is the rate of convictions (rate per 1000 offenders) comitted
by psychiatric patients
Population attributable risk fraction
PAF = PAR / r
is the % of all convictions in the country comitted by
psychiatric patients
Note: PAR and PAF estimates assume that there
is a causal relationship between mental disorder and crime
RESULTS – RAW NUMBERS
Individuals 1988-2000:
T
C
CMCM+
M
T
M = 7 176 361 individuals in population >15
M
441,066 individuals were admitted on at least
one occasion for psych. diagnosis
C
145,860 individuals were convicted of at least
one violent crime
CM-
111,191 individuals without psych admission
were convicted
CM+
34,635 individuals with psych admission
were convicted
RESULTS – RAW NUMBERS
No of violent crimes 1988-2000:
T
C
224,126 violent crimes by
people without psych. admissions
NCM+
114,330 violent crimes by
people with psych. admissions
CMCM+
M
NCM-
NC
total 338,456 violent crimes
RESULTS
r = 45 / 1000
Number of violent crimes per 1000 in the population
Population attributable risk
PAR = 12 (out of 45)
No of violent crimes (per 1000 in the population) committed
by people identified as mentally disordered via the inpatient
register
1. Patients with severe mental illness (psychoses)
2. Substance use patients
1.) SEVERE MENTAL ILLNESS
Psychoses
Psychotic disorders, such as schizophrenia,
schizoaffective disorder, bipolar disorder
- hallucinations
- paranoid ideation
- isolation, anhedionia
- manic conditions
- megalomanic ideation
- severe depression
- catatonic states
Severe Mental Illness (SMI) by sex and age-bands
(Schizophrenia and other psychoses, N = 98 082, during 1988-2000)
Population No. SMI
size
patients
No. crimes
Total no.
committed No. crimes
crimes
by SMI
committed by r
committed patients
others
Age 15-24
Men
Women
561 815
586 683
4 447
3 520
122 946
8 784
3 817
304
119 129
8 480
218.8
15.0
213.7 858.3
14.5 86.4
5.1
0.4
2.3%
2.9%
Age 25-39
Men
Women
930 121
886 551
12 633
11 107
113 794
7 899
9 109
1 194
104 685
6 705
122.3
8.9
114.1 721.1
7.7
107.5
8.2
1.3
6.7%
14.0%
Age 40+
Men
Women
1 998 512 26 321
2 212 679 40 054
65 625
5 335
5 605
1 090
60 020
4 245
32.8
2.4
30.4
1.9
213.0
27.2
2.4
0.5
7.3%
19.0%
All ages, men
All ages, women
3 490 448 43 401
3 685 913 54 681
302 365
22 018
18 531
2 588
283 834
19 430
86.6
6.0
82.3
5.3
427.0
47.3
4.3
0.6
4.9%
10.4%
All ages, men and 7 176 361 98 082
women
324 383
21 119
303 264
45.2
42.8
215.3
2.4
5.2%
r0
r1
PAR per PAF
1000
Fazel & Grann (in press) American Journal of Psychiatry
2.) SUBSTANCE USE DISORDERS
• Alcohol
• Drugs such as amphetamine, cocain and
heroine
• ”Legal drugs used illegally”
(benzodiazepines eg Rohypnol)
• Poly-drug use
Alcohol and Drug Use
(N = 144 146)
No.
No. crimes
No. crimes
individuals committed
committed
admitted to by
by
Principal Diagnosis
hospital
non-patients patients
r
r0
r1
PAR
PAF
Alcohol
105,918
267,558
56,825
48.2
40.4
536.5
7.8
16.2%
Drugs
38,228
265,565
58,818
48.2
42.6
1318.0
5.6
17.6%
11.6%
Any admission for alcohol or drug use: 23.3%
Individual drug classes
Opiates
6,167
316,091
8,292
48.2
Cannabis
3,118
318,679
5,704
48.2
Sedatives
5,004
321,676
2,707
48.2
Cocaine
196
323,992
391
48.2
Amphetamine
5,523
313,049
11,334
48.2
Hallucinogens
293
323,921
462
48.2
Solvents
368
323,791
592
48.2
Poly-drug misuse
13,413
303,446
20,937
48.2
Drug-induced psychosis
4,146
315,984
8,399
48.2
47.0
1344.6
1.2
2.5%
47.4
1829.4
0.8
1.7%
47.9
541.0
0.4
0.8%
48.2
1994.9
0.1
0.1%
46.6
2052.1
1.6
3.4%
48.2
1576.8
0.1
0.1%
48.2
1608.7
0.1
0.2%
45.2
1560.9
3.0
6.3%
47.0
2025.8
1.2
2.5%
Grann & Fazel (2004) BMJ, 328, 1233-1234.
Population-based studies
SUMMARY
• The contribution of mentally disordered inpatients to
violent offending was much higher than expected
• Notably, one third of all aggravated assaults, one fourth of
all assaults, one fourth of all robberies, and a majority of
all homicides were committed by persons who were also
psychiatric inpatients at any time during the 13-year study
period
• However, the contribution to violent crime by people
suffering from psychotic illnesses was small, approx 5%
• The by far largest population attributable risk was seen in
patients hospitalised for substance misuse disorders,
who committed 1 in 4 of all violent crimes.
CONCLUSION
• It makes sense to target the alcohol and drug
clients for risk assessment and violence
prevention programmes!