Treatments for dual diagnosis

What is dual diagnosis?

Many treatments have been targeted to improving symptom severity for people suffering schizophrenia in combination with substance use problems. Studies of dual diagnosis often investigate the effectiveness or availability of treatments for improving outcomes relating to either diagnosis, for example symptom severity, social function, quality of life, substance use, or cognitive outcomes.

 

What is the evidence for pharmaceutical treatments for dual diagnosis?

Moderate to low quality evidence suggests olanzapine may be effective for reducing cocaine use in people with schizophrenia. Low quality evidence is unable to determine the benefits of risperidone for cannabis use, risperidone, haloperidol, chlorpromazine, aripiprazole, or mazindol for cocaine use, and lamotrigine, antidepressants, anti-craving agents, or disulfiram for substance-dependence.

Also see the Course and Outcomes drug and alcohol use topic, the Risk Factor substance use topic, the Living with Multiple Conditions drug and alcohol use topic, and the Psychosocial Treatments for dual diagnosis topic.

September 2016

Treatments for dual diagnosis

What is dual diagnosis?

Dual diagnosis is a term that refers to having both a mental illness and a substance abuse problem. Studies of dual diagnosis investigate the effectiveness and availability of treatments for improving outcomes relating to either diagnosis, such as symptoms, functioning, quality of life, substance use, or cognitive problems.

What is the evidence for the effectiveness of therapy for dual diagnosis?

Moderate quality evidence suggests a medium-sized benefit of motivational interviewing with or without cognitive behavioural therapy for reducing the amount of cannabis used, but no benefit for reducing frequency of cannabis use. There may also be a small benefit for positive, but not negative symptoms. Moderate to low quality evidence suggests a small to medium-sized effect of reduced injection use and reduced stimulant use with contingency management (positive rewards) after 3 months of treatment, but not after 6 months of treatment. Low quality evidence is unclear of the benefits of skills training, group therapy, family therapy, or residential treatments for reducing substance use or improving symptoms.

Also see the Course and Outcomes drug and alcohol use topic, the Risk Factor substance use topic, the Living with Multiple Conditions drug and alcohol use topic, and the Pharmaceutical Treatments for dual diagnosis topic.

March 2016

Anticraving agents

What are adjunctive anticraving medications?

Anticraving medications includes naltrexone (an opioid receptor antagonist), which aims to reduce craving for and use of substances.

What is the evidence for anticraving medications?

Low quality evidence is unclear as to the benefit of anticraving agents such as naltrexone for improving substance dependence in people with schizophrenia.

 

August 2016

Substance use

How is substance use relevant to schizophrenia?

Substance use is more common in people with schizophrenia than in the general population.

What is the evidence for substance use?

High quality evidence shows there is an increased risk of any psychotic symptom or disorder (including schizophrenia) in people who use cannabis. Moderate to high quality evidence suggests this relationship is dose-dependent; increased use of cannabis is associated with increased risk of psychosis.

Moderate quality evidence suggests the prevalence of cannabis use in people with first-episode psychosis is around 33-38%, and initiation of cannabis use is around 6-7 years prior to onset of psychosis. Cannabis use tends to decline with treatment, but with continuing use, there is an increased risk of relapse or re-hospitalisation, and less adherence to treatment.

Moderate to low quality evidence suggests the prevalence of tobacco smoking in people with first-episode psychosis is around 57%. There is a medium-sized increased risk of psychotic disorders, and an earlier age of psychosis onset, in tobacco smokers compared to non-smokers. People with first-episode psychosis smoked tobacco for an average of 5.3 years prior to their first psychotic episode. Males with schizophrenia show higher rates of lifetime tobacco smoking than males with other mental illnesses, with no differences in tobacco smoking rates in females with different mental disorders.

Moderate to low quality evidence suggests there are increased rates of subclinical psychotic symptoms (e.g. pseudohallucinations) or other perceptual disturbances in people who use alcohol or other drugs.

Also see the Course and Outcomes drug and alcohol use topic, the Living with Multiple Conditions drug and alcohol use topic, the Psychosocial Treatments for dual diagnosis topic, and the Pharmaceutical Treatments for dual diagnosis topic.

March 2017

Drug and alcohol use

What is comorbid drug and alcohol use? 

Drug and alcohol misuse, abuse or dependence are concerns for people with schizophrenia due to the association with poor clinical and social outcomes, including high rates of suicide, HIV, homelessness, aggression and incarceration. Moreover, substance use places additional burden on patients, families, psychiatric services, and government resources due to high rates of treatment non-adherence and relapse.

This topic covers outcomes for people with schizophrenia and comorbid substance use (termed ‘dual diagnosis’).

What is the evidence on outcomes for patients with drug and alcohol use?

High quality evidence shows a small increase in positive symptoms and a medium-sized reduction in negative symptoms in people with schizophrenia and a current substance use disorder compared to people with schizophrenia without a current substance use disorder. Moderate quality evidence suggests patients with current substance use are also more likely to have depressive symptoms. Patients with a mixed psychoactive substance use disorder or a cocaine use disorder show increased extrapyramidal (movement) symptoms, particularly akathisia and tardive dyskinesia compared to patients without a substance use disorder.

High quality evidence shows a small to medium-sized increase in global cognition, processing speed, planning, visual and working memory, attention and psychomotor skills in people with psychosis and a current polysubstance or cannabis use disorder. People with psychosis and a cocaine use disorder showed better attention and psychomotor skills than people with psychosis with no substance use disorder. Conversely, moderate quality evidence suggests more impaired working memory in patients with an alcohol use disorder compared to patients with no substance use disorder.

High quality evidence shows a small effect of longer hospital stays in people who continued cannabis use after onset of psychosis compared to non-users. There is also higher rates of relapse in people who continued cannabis use compared to people who discontinued cannabis use after first onset of psychosis. Moderate to low quality evidence suggests an increased risk of treatment non-adherence, relapse and re-hospitalisation in people with first-episode psychosis and cocaine, opiates, or ecstasy use. Moderate quality evidence suggests a small decrease in global functioning in people with psychosis and a current substance use disorder compared to people with psychosis and a former substance use disorder, and in people with former substance use compared to people with no former substance use disorder.

Also see the substance use as a risk factor topic, the topic on rates of substance use in people with schizophrenia (drugs and alcohol, smoking), and the topics on treatments for dual diagnosis  (pharmaceutical and psychosocial).

March 2016

Drug and alcohol misuse

How is drug and alcohol misuse related to schizophrenia? 

Drug and alcohol misuse, abuse or dependence are concerns for people with schizophrenia due to the association with poorer clinical and social outcomes, including high rates of suicide, HIV, homelessness, aggression and incarceration. Moreover, comorbid substance use places additional burden on patients, families, psychiatric services, and government resources due to high rates of treatment non-adherence and relapse.

What is the evidence for comorbid drug and alcohol misuse?

Moderate quality evidence suggests the lifetime prevalence rates of any illicit drug misuse, abuse or dependence range from 17% in rehabilitation and long-term settings, to 70% in community health settings. Any lifetime substance use, particularly cannabis, is associated with an earlier age of onset of psychosis.

Moderate quality evidence suggests prevalence of any cannabis use in first episode psychosis patients is around 33-38%, and moderate to low quality evidence suggests lifetime prevalence of cannabis use disorders in people with schizophrenia is around 27%, with current prevalence around 16%. Prevalence is higher in males compared to females, in people under 30 years of age compared with people over 30 years of age, and in people with first episode schizophrenia compared with people with chronic schizophrenia. The initiation of cannabis use is around 6-7 years prior to onset of psychosis, and continuation of cannabis use declines after treatment.

Moderate quality evidence suggests the rate of stimulant use disorders in people with psychosis is around 9%. Studies including patients with affective psychosis, inpatients, cannabis users, and those from USA and Australia report the highest rates of stimulant use.

Moderate quality evidence suggests lifetime prevalence rates of alcohol misuse, abuse or dependence in people with schizophrenia range from 29% in rehabilitation and long-term settings to 75% in community health settings. Prevalence is higher in studies using the Diagnostic and Statistical Manual of Mental Disorders (DSM) III-revised diagnostic criteria compared to studies using DSM-IV, International Classification of Diseases (ICD) 9 or 10. Prevalence is higher in samples aged 30 to 40 years compared with other age groups, and in studies published between 1990 and 1995 compared with earlier publications.

Also see the Course and Outcomes drug and alcohol use topic, the Risk Factor substance use topic, the Psychosocial Treatments for dual diagnosis topic, and the Pharmaceutical Treatments for dual diagnosis topic.

 

March 2016