The Effect of Comorbid Alcohol/Substance Use

July 10, 2026 updated by: Melisa BULUT, Abant Izzet Baysal University

The Effect of Comorbid Alcohol/Substance Use on Social Inclusion and Clinical Outcome in Individuals With Severe Mental Illness Enrolled in a Community Mental Health Center: A Cross-Sectional Case-Control Study

Study Design This study was designed as a comparative, cross-sectional case-control study examining the effect of comorbid alcohol and substance use disorder (ASUD) on clinical course and social inclusion among individuals with severe mental illness followed at a Community Mental Health Center (CMHC). The study did not involve any interventions.

Aim The aim of this study is to examine the effect of comorbid alcohol and substance use on clinical course parameters-such as number of hospitalizations and medication dosages-and on social inclusion indicators-such as employment, social participation, and social adjustment-among individuals with severe mental illness followed at the CMHC, in comparison with a matched control group without substance use.

Research Questions

What are the rates of comorbid alcohol and substance use among patients with severe mental illness followed at the CMHC? What are the current addiction symptoms, number of hospitalizations, and employment rates among individuals with severe mental illness and comorbid ASUD? What is the level of continuity of CMHC engagement and social participation among individuals with severe mental illness and comorbid ASUD, and what factors influence it? How does the level of social inclusion among individuals with severe mental illness and comorbid ASUD compare with that of individuals without ASUD?

Hypotheses

H1: The average annual number of hospitalizations among individuals with a dual diagnosis (severe mental illness + ASUD) followed at the CMHC is significantly higher than among those without substance use.

H2: Among individuals with a dual diagnosis, the daily medication doses (e.g., chlorpromazine equivalents) required to control psychotic or manic symptoms are higher than in the control group.

H3: Social inclusion is lower among patients with substance use compared with the control group.

H4: Employment rates among individuals with a dual diagnosis are significantly lower than among those with severe mental illness alone.

H5: Substance use negatively affects patients' social participation, including involvement in activities and friendships.

H6: Attendance rates at CMHC workshops and rehabilitation programs are lower among individuals with substance use compared with the control group.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Study Setting and Sample The study will be conducted at the Bolu İzzet Baysal Mental Health and Diseases Rehabilitation Center , which has a follow-up pool of approximately 1,300 active patients. The study population consists of these 1,300 individuals. The sample size was calculated using Cochran's formula with finite population correction, at a 95% confidence level and a 5% margin of error. This calculation yielded a minimum sample size of 297 individuals. Case and control groups will be distributed in an approximately 1:1 ratio (148 cases, 149 controls).

Data Collection Form

  1. Sociodemographic Variables Age, gender, marital status, education level, living arrangement (living with family/alone/in an institution, etc.), employment status (employed, unemployed, retired, or receiving a disability pension), and social security status.

  2. Clinical Variables

    Primary psychiatric diagnosis (per DSM-5: schizophrenia spectrum disorders or bipolar disorder) ASUD diagnosis and type of substance used (alcohol, cannabis, stimulants, etc.) Duration of illness (in years) Length of follow-up at the Rehabilitation and Treatment Center (in months) Number of psychiatric hospital admissions and total days of hospitalization over the past 2 years Calculated daily chlorpromazine-equivalent (CPZ-eq) dose of antipsychotic and mood-stabilizing medications used Treatment adherence, assessed based on prescription refill frequency and clinical follow-up notes Substance use will be assessed using the Drug Abuse Screening Test (DAST-10) and alcohol use using the Alcohol Use Disorders Identification Test (AUDIT)

  3. Social Inclusion and Rehabilitation Variables

    Attendance rate at TRSM workshops and rehabilitation programs (number of sessions attended / number of sessions planned) Indicators of social adjustment: employment status, independent living skills, and breadth of social network (relationships outside the family) Number of emergency department visits over the past 12 months Social Exclusion (Ostracism) Scale score

  4. Drug Abuse Screening Test (DAST-10) The DAST-10 is a 10-item self-report instrument developed to screen for problems related to the use of substances other than alcohol and tobacco. Developed by Harvey A. Skinner, it assesses substance-related problems over the past 12 months. Items are answered yes/no, with each "yes" scored as 1 point (item 3 is reverse-scored). Total scores range from 0 to 10, with higher scores indicating more severe substance use problems. A Turkish validity and reliability study found an internal consistency coefficient of Cronbach's α = 0.92. That study recommended a cutoff score of ≥4, yielding a sensitivity of 0.98 and specificity of 0.91. The scale is widely used to rapidly screen for substance use problems in clinical and research settings.
  5. Alcohol Use Disorders Identification Test (AUDIT) The AUDIT is a screening instrument developed to identify hazardous and harmful alcohol use. It was developed by Thomas F. Babor and colleagues as part of a multicenter study conducted by the World Health Organization (WHO). The AUDIT consists of 10 items assessing frequency of alcohol use, symptoms of dependence, and alcohol-related problems over the past 12 months. Items are scored on a 0-4 Likert-type scale, yielding a total score range of 0-40, with higher scores indicating more hazardous drinking. A Turkish validity and reliability study confirmed the Turkish version as a valid and reliable measurement tool; a cutoff score of 8 or above is generally accepted to indicate hazardous/harmful alcohol use. The AUDIT is widely used in clinical and research settings for rapid, effective screening of alcohol-related risk. The scale's total possible score is 40, with a cutoff of 8, and its reliability coefficient is 0.65.
  6. Social Exclusion (Ostracism) Scale This is a brief self-report scale developed to assess the frequency of social exclusion (ostracism) experiences in individuals' daily lives. Developed by Sandra C. Rudert and colleagues, it measures exclusion experiences over the preceding two months. The scale consists of 4 items with a unidimensional structure, rated on a 7-point Likert scale (1 = Never, 7 = Always). The total score is calculated by summing item scores, with higher scores indicating more frequent experiences of social exclusion. Confirmatory factor analysis supported a single-factor structure with good model fit (CFI = 0.99, RMSEA = 0.04), and internal consistency was high (Cronbach's α = .90), confirming the scale as a reliable measurement tool.

Study Type

Observational

Enrollment (Estimated)

297

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Adults with alcohol and substance use disorders among individuals with severe mental illness who are being followed up at the Community Mental Health Center.

Description

Inclusion Criteria:

  • Being 18 years of age or older,
  • Having a diagnosis of Schizophrenia Spectrum Disorder and Other Psychotic Disorders or Bipolar Disorder according to DSM-5 diagnostic criteria,
  • Being actively followed up at the TRSM for at least 6 months.

Exclusion Criteria:

  • Individuals diagnosed with organic brain damage or neurodevelopmental disorders (intellectual disability, etc.),
  • Individuals with severe cognitive impairment that prevents them from communicating adequately.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Case group
Patients will be divided into two groups based on whether or not they have a concomitant diagnosis of Alcohol and Substance Use Disorder (ASUD): (1) Dual diagnosis group (Severe Mental Illness + Alcohol and Substance Use Disorder)
Other: case (comorbid diagnosis)

Patients who already have a comorbid diagnosis of Alcohol and Substance Use Disorder (ASUD) have been exposed to alcohol and substances. Data will be collected by administering the scales to these patients.

Social Inclusion and Rehabilitation Variables Substance Use Risk Screening Test (DAST-10) Screening Test for the Diagnosis of Alcohol Use Disorders (AUDIT) Social Exclusion (Ostracism) Scale
Control group
(2) Control group (Severe Mental Illness, no Alcohol and Substance Use Disorder). The diagnosis of Alcohol and Substance Use Disorder will be determined according to DSM-5 criteria and the recorded diagnosis in the interview and clinical follow-up notes in the community mental health center physician records.
Other: control
Social Inclusion and Rehabilitation Variables Substance Use Risk Screening Test (DAST-10) Screening Test for the Diagnosis of Alcohol Use Disorders (AUDIT) Social Exclusion (Ostracism) Scale

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Ostracism
Time Frame: Baseline
The level of ostracism will be compared in case and control groups. The effect of alcohol and substance use disorder on the level of ostracism will also be examined.Ostracism will be measured using the "Social Exclusion Scale." The scale is a self-report scale consisting of four items. The minimum score on the scale is 4, and the maximum is 28 points. The total score obtained from the scale will be calculated by summing the items, and higher scores will indicate that the individual experiences social exclusion more frequently. This will show whether the case group or the control group experiences higher levels of ostracism.
Baseline

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Abant Izzet Baysal University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 20, 2026

Primary Completion (Estimated)

September 30, 2026

Study Completion (Estimated)

December 30, 2026

Study Registration Dates

First Submitted

June 23, 2026

First Submitted That Met QC Criteria

July 3, 2026

First Posted (Actual)

July 9, 2026

Study Record Updates

Last Update Posted (Actual)

July 13, 2026

Last Update Submitted That Met QC Criteria

July 10, 2026

Last Verified

July 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • AIBU-PSK-MB-06

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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