Substance use patterns in persons with psychosis

Abstract

Clinical experience suggests that people with psychosis generally show a diverging substance use pattern compared with other people with ‘dual disorders’. The aim of this study was to describe substance use patterns in individuals with psychosis and relate these to substance use patterns in persons with other kinds of psychiatric disorders in combination with substance abuse. A wider aim was to contribute to a deeper understanding of interactions between mental illness and substance use. Two groups were recruited, one with persons diagnosed with psychotic disorders and one with people with other (mainly anxiety- and affective-) disorders. All participants also had substance-related problems. The participants completed the questionnaires Alcohol Use Disorders Identification Test and Drug Use Disorders Identification Test, and information about socio-demographic and care-related characteristics was collected. Group differences were calculated. The participants with psychosis scored significantly lower on most questions concerning affective/cognitive aspects of drug use, such as longing, guilt and experience of failing in relation to alcohol and drugs. They also showed fewer indications of alcohol dependence. A possible interpretation is that the findings reflect group differences in mentalization and affect-regulation relevant to both substance use and psychiatric illness. This may have implications for theoretical understanding of dual disorders as well as for psychotherapeutic treatment.

Keywords:

• substance use
• psychosis
• co-existing problems
• dual diagnosis
• mental health

Notes

1. Including some cases of drug-induced psychosis with a duration of more than one month in spite of abstinence, which qualifies for re-diagnosing to psychotic disorder not otherwise specified according to DSM-IV (American Psychiatric Association, 2000). No cases of bipolar disorder were included.

2. Berman et al. (2005, 2012) suggest, on statistical basis, a cut-off level of two points for women, but for this study, we have chosen to use a six-point level for both genders since lesser scorings may be obtained in the case of substance use that occurred more than one year before the assessment.

3. Nicotine use was not assessed in this study.

4. The patient stock of the unit the psychosis group was recruited from is about 85% male, which is the main explanation of the obvious misallocation in the study.