Psychosocial interventions for people with both severe mental illness and substance misuse (Review)

Dual diagnosis is the name often given to people who have a severe mental health problem and a drug and/or alcohol problem as well. While the number of people with these problems varies, in some urban areas it can be over 50% of all those with mental health difficulties. Although individuals may feel they are self-medicating when using these substances, drugs and alcohol can have a detrimental effect on the symptoms of their illness, the way their medication works and their interaction with the wider world. They can also make people more vulnerable to suicide, hepatitis, HIV and homelessness, and can cause them to be aggressive or to do something that moves them into the criminal justice system. People who have a substance abuse problem but no mental health problem can be helped by a variety of interventions that look at their motivation for change (motivational interviewing - MI), how to adapt their behaviour by improving coping strategies (cognitive behavioural therapy - CBT), a supportive approach similar to the one used by Alcoholics Anonymous and skills training. These are all examples of psychosocial interventions. However, using these interventions on people with mental health problems is more complex, because it is unclear whether the intervention for the substance abuse should be offered with that for the mental health problem and whether the same team should be responsible for both (integrated intervention). This review attempts to assess all trials using psychosocial interventions compared to care as usual where they are used to help those who have a substance abuse problem and a severe mental illness. Twenty-five studies were identified containing a total of 2478 people. They were all in the United States, Australia or the United Kingdom. Two were based in a hospital, 19 in the community, two in hospital and the community and two in the community and in jail. They used different psychosocial interventions, with four trials using integrated models of care, four using non-integrated, three combining MI and CBT, four using CBT, five using MI and two using skills training. Trials lasted from three months to three years. No trial showed any definitive difference between the psychosocial intervention and the usual treatment, although the difference in the study designs made it difficult to compare one trial to another. There are also problems caused by high dropout rates, differences in the outcome measures and dependability in the way psychological interventions were used. To allow more thorough assessment of whether psychosocial interventions work for people with substance abuse problems and severe mental illnesses, more quality trials are needed which address these problems.