Transcript Prevalence of Co-morbidity amongst Substance Misuse

Prevalence & Management of
Co-morbidity: Findings from
the COSMIC study
Tim Weaver
Centre for Research on Drugs & Health Behaviour
Department of Primary Care and Social Medicine /
Department of Psychological Medicine
Imperial College London
The COSMIC Study:
Co-morbidity of Substance Misuse &
Mental Illness Collaborative Study
THE STUDY TEAM
Imperial College: Tim Weaver, Vikki Charles, Zenobia Carnwath, Peter
Madden, Dr Adrian Renton, Prof Gerry Stimson, Prof Peter Tyrer, Prof.
Thomas Barnes, Dr Chris Bench, Dr Susan Paterson
C&NWL Mental Health NHS Trust : Dr William Shanahan
Dr Jonathon Greenside, Dr Owen Jones,
Turning Point, Brent: Dr Chris Ford
Community Health Sheffield NHS Trust: Dr Nicholas Seivewright
Helen Bourne, Dr Muhammad Z Iqbal,
Nottingham Healthcare NHS Trust: Dr Hugh Middleton
Sylvia Cooper, Dr Neil Wright, Dr Katina Anagostakis,
Aims of the Presentation
• Review epidemiological data on co-morbidity &
summarise evidence about the prevalence and
nature of co-morbidity in SM and MH treatment
populations generated by the COSMIC study.
• Discuss implications for service development in
the context of;
– current policy, and,
– recent evidence for the effectiveness specialist
treatment or service delivery interventions.
METHOD
Study Aims
• To estimate the prevalence of co-morbid substance
misuse and mental health problems (co-morbidity)
amongst current patients of substance misuse and
mental health services.
• To describe the range of co-morbid presentations
among these populations
• To assess the treatment needs (met and unmet)
• Assess whether there are differences in the
prevalence of co-morbidity between populations
drawn from London and provincial urban areas.
Study Design
DESIGN:
• Cross sectional survey in four centres.
• Census of CMHT & substance misuse caseloads &
assessment interviews with random samples from each
population
ASSESSMEMTS:
• Alcohol: AUDIT
• Non-prescribed drugs: Questions about use in past
year / month by drug type, Severity of Dependence
Scale & Hair & Urine analysis (MH sample ONLY)
• Psychosis: OPCRIT.
• Personality Disorder: PAS–Q
• CPRS (measures global symptomatology) sub-scales for
assessment of Depression (MADRS) Anxiety (BAS)
FINDINGS
FINDINGS: Drug Services
Subjects:
• Assessed & allocated on census date
• Random interview sample of 353 cases selected
• Full patient interview & casenote audit data
obtained in 278 cases (79%)
• Study Populations:
– Drug Services (n=216): 93% in treatment for problems
related to opiate use. 78% report lifetime injecting drug
use
– Alcohol Services (n=62): AUDIT confirmed 57 (92%)
used alcohol at ‘harmful levels’, 2 (3%) abstinent, 3 (5%)
reported non-harmful use
Service Reported Co-morbidity (year)
• Service recorded psychiatric diagnosis obtained from
keyworkers who also identified cases needing MH
assessment
• We compared this with ‘gold standard’ measures
obtained at interview
 KEY FINDING: Reported diagnosis lacks validity,
under-estimates prevalence of psychiatric disorder
• Specificity good (>90%), sensitivity poor (20% - 35%)
Drug Treatment Population:
Prevalence of Drug Use (Past Month)
N
(%)
Heroin
107
(51.7) *
Stimulants
85
(41.1) *
Crack Cocaine
67
(32.4)
Cocaine Powder
26
(12.6)
Amphetamine
18
(8.7)
Non-prescribed sedatives, benzo’s
61
(29.5)
Cannabis
129
(62.3)
60
(29.0)
ALCOHOL
Harmful or hazardous use in past year
(and reported use in past month)
* 38% used opiates and stimulants in past month
Drug Treatment Population
Prevalence of Psychiatric Disorder (year)
(n=216)
n
(%)
95% CI
Psychotic disorder
17
(7.9)
4.7- 12.3
Personality disorder
80
(37.0)
30.6 – 43.9
Severe Depression
58
(26.9)
21.1 – 33.3
Minor Depression
87
(40.3)
33.7 – 47.1
Severe Anxiety
41
(19.0)
14.0 – 24.9
One or more disorder
161
(74.5)
68.2 – 80.2
Drug Treatment Population
Prevalence estimates compared
Prevalence high but consistent with previous estimates
• Psychosis: 7.9% (year). 9 times general pop rate
(Jenkins et al, 1998)
– Compares with 6.2% (lifetime) (Regier et al, 1990)
• Severe Depression: 26.9% (year).
– Estimates in US and Europe 23% - 37% (Regier et al, 1990;
Limbeek et al, 1992; Hendriks, 1990).
• Personality Disorder: 37%.
– Range of estimates (35% - 73%) (Verheul, 2001).
Drug Treatment Population
Prevalence of Psychiatric Disorder (year)
35
30
25
Psychosis
PD
Severe Dep
Minor Dep
No disorder
Alc misuse
20
15
10
5
0
Psychosis
PD
Depression
No
disorder
Drug Treatment Population
Services providing mental health
interventions (past month) for co-morbid
patients (n=161)
Alcohol Treatment Population
Prevalence of Psychiatric Disorder (year)
(n=62)
N
(%)
95% CI
Psychotic disorder
12
(19.4)
10.4 - 31.4
Personality disorder
33
(53.2)
40.1 – 66.0
Severe Depression
21
(33.9)
21.1 – 33.3
Minor Depression
87
(40.3)
22.3 – 47.0
Severe Anxiety
20
(32.3)
20.9 – 45.3
One or more disorder
53
(85.5)
74.6 – 92.7
FINDINGS: Community Mental Health
Team Population
SUBJECTS
• CPA patients, aged 16-64, assessed and allocated to CMHT on
census date
• Random interview sample of 400 cases selected
• Interviews completed in 282 (70.5%) cases
• Study Population - Psychosis: 77%, PD & Depression: 16%,
severe depression: 7%
 KEY FINDING: Service reports of substance misuse lacked
validity, and under-estimated prevalence. Prevalence estimation
based on Interview sample.
Mental Health Population
Self-reported co-morbidity (year)
(n=282)
N
%
95% CI
Problem Drug Use
84
(29.8)
24.5 – 35.5
Drug Dependence
47
(16.7)
12.5 – 21.5
Alcohol Misuse
72
(25.5)
20.5 – 31.0
Drug use &/or Alcohol
124
(44.0)
38.1 – 49.9
Mental Health Population
Self-reported Drug Use (year)
N=282
n
%
95% CI
Cannabis
71
(25.2)
20.2 – 30.7
Sedatives
21
(7.4)
4.6 – 11.2
Crack / Cocaine
20
(7.1)
4.4 – 10.7
Opiates
14
(5.0)
2.7 – 8.2
Ecstasy
11
(3.9)
2.0 – 6.9
Amphetamines
11
(3.9)
2.0 – 6.9
Mental Health Population
Prevalence estimates compared
PROBLEM DRUG USE:
• Prevalence higher than previously reported
– 30.9% vs 15.8% (Menezes et al, 1996)
• Significant differences between London & non-London
– Problem drug use: 42.1% v 21.4%; x21df=13.9, p<0.001
– Drug dependency: 24.6% v 11.3%; x21df=8.6, p=0.005
ALCOHOL MISUSE:
• Prevalence (25.2%) comparable with other UK studies
– 20% - 32% (Wright et al, 2000; Duke et al, 1994; Menezes et al,
1996).
• No significant difference between London & non-London
Mental Health Population
Services providing Alcohol related
interventions to patients with harmful
alcohol use (n=72)
Mental Health Population
Services providing drug related
interventions to patients with problem
drug use (n=84)
DISCUSSION
&
CONCLUSIONS
IMPLICATIONS FOR SERVICE
DEVELOPMENT
Prevalence
Prevalence is high in both treatment populations
– Most drug patients have some psychiatric disorder
– Poly-drug use is highly prevalent in drug treatment
populations (and associated with co-morbid mental
health problems)
– In some centres co-morbid patients represent majority
of CMHT patients
Clinical presentations heterogeneous
Management
• Assessment: MH & SM services fail to identify
co-morbidity in a high proportion of patients
• Few patients meet criteria for joint management.
Possibly ‘low potential’ for cross-referral?
• Drug & Alcohol services provide some MH
interventions, >50% get no specialist care
• CMHTs provide interventions for very few
patients with drug / alcohol problems (<20%)
Policy Implications
• Co-morbidity too prevalent to be managed by subteams or ‘dual-diagnosis’ specialists
• Heterogeneity (and low cross-referral potential)
means full extent of co-morbidity cannot be managed
by parallel or serial treatment models
• Co-morbidity needs to be managed systemically
within mainstream mental health services
• SM services need additional resources to better
manage non-referable co-morbidity
– Develop capacity to manage co-morbidity within MH & SM
services
– Training a priority if effective management is to be achieved
– Research needed to support development of evidence-based
service models & treatment interventions
COSMIC Study Publications:
• Weaver, T., et al (2003) Co-morbidity of substance misuse
and mental illness in community mental health and
substance misuse services. British Journal of Psychiatry,
183, 304-313.
• Weaver, T., et al. (2004) What are the implications for
clinical management and service development of prevalent
co-morbidity in UK mental health and substance misuse
treatment populations? Drugs: Education, Policy &
Prevention, 11(4), 329-348.
• Jones, OB et al (2004) Prevalence of personality disorder
in a substance misuse treatment population and
associated co-morbidity. Addiction, 99, 1306-1314.
• Executive Summary of Dept of Health report:
http://www.mdx.ac.uk/www/drugsmisuse/execsummary.html
• NTA. Research in to Practice Series (forthcoming)