CBT / MI effective for combined mental health and alcohol problems - implications for 'dual diagnosis'?

Which comes first - alcohol misuse or mental illness?

Dual diagnosis - co-existing substance misuse and mental health problems - has long been a thorny issue for the alcohol field when it comes to treatment. It is acknowledged that

there is a clear association between having a mental illness and increasing risk of alcohol dependence (to quote the Govenment's alcohol strategy),

and that the reverse is also true, i.e.

individuals presenting for treatment with alcohol misuse may also present with features of other psychiatric disorders, most commonly anxiety or depression. For many, these symptoms will be closely linked to their alcohol misuse and lessen when drinking is reduced or stopped (to quote NICE guidance). 

Who treats what and when if the patient has a dual diagnosis?

The problem seems to be knowing which diagnosis to treat first; it all gets a bit chicken and egg. The NHS 2002 Dual Diagnosis Good Practice Guide told substance misuse services and, more pointedly, mental health services to get their act together, stop 'shunting patients between different sets of services', and to 'mainstream' treatment for people with severe mental health problems and co-occuring substance misuse issues within mental health services.

IAPT (Improving Access to Psychological Therapies) - an NHS programme rolling out services across England offering interventions for treating people with depression and anxiety disorders - will be accessable to the whole adult population by April 2015, and is a major plank in the Government's mental health stratety for England No health without mental health. The mainstreaming message of 2002 needed another push ten years on, however, with publication of  IAPT positive practice guide for working with people who use drugs and alcohol, which said:

IAPT services do not provide complex interventions to treat substance use problems but drug and alcohol use should not be an automatic exclusion criterion for accessing psychological therapy

Meanwhile, current NICE guidance CG115 (Alcohol dependence and harmful alcohol use), having reviewed the available evidence, recommends that:

the first step in treating people presenting with alcohol misuse and comorbid depression/anxiety is to treat the alcohol misuse. Given that the presence of a comorbid disorder following a reduction in alcohol consumption is associated with a poorer long-term prognosis, an assessment of the presence and need for treatment for any comorbid depression or anxiety should be considered 3 to 4 weeks after abstinence is achieved

 Treat both at the same time!

So, arguably, mental health services can still justifiably bounce dual diagnosis patients back to alcohol services. However, a new meta analysis, reviewed by Prof Matt Field on the excellent Mental Elf blog, suggests a way forward. The analysis found that compared to other psychological therapies, cognitive based therapy (CBT) and/or motivational interviewing (MI) for comorbid alcohol use disorder and major depressive disorder produced small but robust beneficial effects on both depression and alcohol consumption.

In conclusion, Prof Field suggests the following clinical implications:

• Treatment of comorbid alcohol use disorder and major depressive disorder with CBT / MI seems to produce beneficial effects on both outcomes.
• Clinicians don’t need to identify a ‘primary’ diagnosis and treat that in the hope that the other will resolve; both can be treated at once.