Condition category
Mental and Behavioural Disorders
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Not provided at time of registration

Trial website

Contact information



Primary contact

Prof Graham Thornicroft


Contact details

Health Services and Population Research (PO29)
Institute of Psychiatry
Kings College
De Crespigny Park
Denmark Hill
United Kingdom
+44 (0)207 848 0735

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title


COMO (Mental health care for dual diagnosis COMOrbidity)

Study hypothesis

Outcomes were investigated at both staff and patient levels. At the patient level, the primary hypotheses were that, compared with patients on control group care coordinators’ caseloads, patients on caseloads of the experimental group key workers, would have:
1. diminished use of in-patient services, reflected in significantly lower bed day use over an 18-month follow-up period
2. reduced alcohol and drug consumption, reflected in lower quantity of alcohol and drugs consumed over the month before interview

Secondary hypotheses were that the intervention would also be associated with significantly:
1. diminished levels of homelessness, violence, suicidal behaviour, imprisonment and detention under the Mental Health Act
2. better social functioning, particularly in relation to self care and hostile and aggressive behaviour
3. diminished symptom severity
4. increased adherence to treatment
5. greater satisfaction with services
6. lower overall costs of care

Regarding staff, the main hypotheses were that a significant increase:
1. in knowledge about dual diagnosis
2. in substance abuse intervention skills and more positive attitudes to working with this client group would be observed in staff receiving the experimental training and supervision package

Ethics approval

Institute of Psychiatry, Kings College London, Research Ethics Committee, approved in 1999, Ref: 075/99

Study design

A cluster randomised controlled trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type

Not Specified

Patient information sheet


Severe and enduring mental illness and comorbid substance abuse or dependence


Each cluster consisted of the clients on a particular case managers' caseload. The unit of randomisation was the case manager. The experimental group consisted of case managers (and the service users with dual diagnosis on their case load) who had been randomly allocated to receive training in dual diagnosis interventions and the control group were case managers (and the service users with dual diagnosis on their case load) who had not been allocated to receive training.

Case managers in the experimental group received a 5 day training course in detection, assessment and interventions for people with dual diagnosis that aims to increase engagement with care and increase motivation to reduce or abstain from using drugs and alcohol.

Intervention type



Not Specified

Drug names

Primary outcome measures

Service users: Hospital bed use over the preceding 18 months, including admission to hospitals outside the catchment area on an extra-contractual referral basis.
Other service use recorded using the Client Service Receipt Inventory
Case managers: Alcohol and Alcohol Problems Perceptions Questionnaire

Secondary outcome measures

Service users:
1. Current adherence to medication, rated using the Medication Compliance Scale, which yields a single rating for the extent to which the patient is believed to adhere to prescribed medication
2. Stage of treatment rated using the Substance Abuse Treatment Scale (SATS), which yields a single rating of the extent to which a patient with dual diagnosis is motivated for and engaged in substance misuse treatment
3. Met and unmet needs, rated using the Camberwell Assessment of Need Short Assessment Schedule (CANSAS), which elicits ratings of patients’ needs in 22 social and clinical domains
4. Social functioning, rated using the Life Skills Profile (LSP)
5. Drug and alcohol consumption and associated problems, measured using the section of the Maudsley Addictions Profile (MAP) which records consumption over a month, the Alcohol Use Disorders Identification Test (AUDIT), which screens for alcohol-related problems and may be used to categorise drinking as hazardous or harmful, and the DALI, a screening instrument for problematic drug and alcohol use developed specifically for severely mentally ill populations
6. Service satisfaction, measured by the brief global Client Satisfaction Questionnaire (CSQ-8) and the Treatment Perception Questionnaire, a short instrument developed specifically to assess satisfaction with substance misuse treatment
7. Physical symptoms, rated using the section of the MAP which enquires how often 10 common physical symptoms have been experienced in the past 30 days
8. Psychiatric symptoms, rated using the Brief Psychiatric Rating Scale (extended version)

Overall trial start date


Overall trial end date


Reason abandoned


Participant inclusion criteria

All case managers were invited to participate unless they were temporary staff or had firm plans to leave during the next 18 months.
Service user inclusion: a clinical diagnosis (made by psychiatrists and recorded in casenotes) of schizophrenia or schizoaffective disorder (ICD 10 codes F20, F25), delusional disorder and other non-affective psychotic illnesses (F22, F29) or bipolar affective disorder (F31) on the caseloads of participating case managers and in addition a rating of substance "abuse" or "dependence" on the Clinician Alcohol Use Scale (CAUS) and the Clinician Drug Use Scale (CDUS) based on DSMIII-R criteria.

Participant type


Age group

Not Specified


Not Specified

Target number of participants

44 case managers and 220 service users

Participant exclusion criteria

Case managers excluded if they had immediate plans to leave or be absent for the study period service users were excluded if they had diagnoses other than stated above.

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Health Services and Population Research (PO29)
United Kingdom

Sponsor information


Kings College London (UK)

Sponsor details

The Strand
United Kingdom
+44 (0)207 836 5454

Sponsor type




Funder type


Funder name

Culyer grant. Ref: GTCUL (UK)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Results - basic reporting

Publication summary


Publication citations

  1. Results

    Miles H, Johnson S, Amponsah-Afuwape S, Finch E, Leese M, Thornicroft G, Characteristics of subgroups of individuals with psychotic illness and a comorbid substance use disorder., Psychiatr Serv, 2003, 54, 4, 554-561.

Additional files

Editorial Notes