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 DesignDESIGN:• 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)

ALCOHOL

Harmful or hazardous use in past year

(and reported use in past month)

60 (29.0)

* 38% used opiates and stimulants in past month

Drug Treatment PopulationPrevalence 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 PopulationPrevalence of Psychiatric Disorder (year)

0

5

10

15

20

25

30

35

Psychosis PD Depression Nodisorder

Psychosis

PD

Severe Dep

Minor Dep

No disorder

Alc misuse

Drug Treatment Population Services providing mental health

interventions (past month) for co-morbid patients (n=161)

Alcohol Treatment PopulationPrevalence 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 PopulationSelf-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 PopulationSelf-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 PopulationPrevalence 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 sub-teams 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)