Schizophrenia Spectrum and Other Psychotic Disorders

Atypical antipsychotics appear to be the first line of treatment of comorbid psychotic illness and substance use disorders. 

For people with alcohol use disorders and schizophrenia, no compelling evidence supports one psychosocial treatment over another to reduce substance use or improve mental state. A Cochrane review of treatment programs for people with both severe mental disorder and substance misuse, including alcohol, suggests that the evidence is poor at best with very few studies available for analysis.  

However, one trial demonstrated effectiveness of motivational interviewing in increasing abstinence from alcohol in this population. 

Cognitive behavioural therapy also appears to be effective in treating those with comorbid psychoses. For example, integrating motivational interviewing, cognitive behavioural therapy and family intervention with routine psychiatric care has been shown to produce greater benefits for people with comorbid schizophrenia and substance use disorders than routine psychiatric care alone. Typical benefits have included better general functioning, a reduction in positive symptoms, and an increase in the percentage of days abstinent from alcohol or drugs. 

Integrating the psychosocial treatment for the mental disorder with the psychosocial treatment for alcohol use disorder may be beneficial. Relapse prevention strategies should consider triggers for both alcohol use and mental disorders. 

Specific motivational interviewing, contingency management and specialist dual diagnosis residential programs are reported as possibly effective in Marel et al (2016). 

Chapter Recommendation Grade of recommendation
21.22 CBT including motivational interviewing appears to be beneficial for people with alcohol use disorder and schizophrenia. C
21.23 Contingency Management appears to improve alcohol outcomes for people with alcohol use disorder and schizophrenia and may be added to other treatments for psychosis. C
21.24 Longer term (12 month or more) specialist dual diagnosis residential program (if available) may be associated with increased abstinence and decreased risk of homelessness. C

Pharmacotherapy should be offered as described in Chapter 10

Limited evidence shows that among people with schizophrenia, two atypical antipsychotics (risperidone and clozapine) may reduce alcohol misuse, smoking, and possibly some other substance misuse. 

Addition of psychosocial support to pharmacological treatment has been shown to be effective in treatment of comorbid psychosis and alcohol use disorders. 

Clinicians should recognise the potential for poor medication adherence in people who drink heavily that are prescribed antipsychotic medications. There is the potential for excess sedation if alcohol is consumed that may influence safety of these medications in those with AUD.

Chapter Recommendation Grade of recommendation
21.25 Disulfiram should not be first line pharmacotherapy for people experiencing psychotic and alcohol use disorders GPP
21.26 Clozapine appears to be more effective than other antipsychotics in reducing symptoms of psychosis in people with comorbid schizophrenia and alcohol use disorder without significant impact on drinking C