People with substance abuse problems who are also depressed may benefit from psychotherapy that addresses both issues — but trying to treat substance abuse and anxiety at the same time isn't effective, and may even be harmful, a Danish researcher reports.

In the United States, about half of people with drug dependence and a quarter of alcohol-dependent individuals also suffer from depression, Dr. Morten Hesse of the University of Aarhus in Copenhagen notes in his report in BMC Psychiatry. The prevalence of clinical anxiety in people with drug or alcohol dependence is roughly similar.

Consensus is growing that so-called integrated psychological treatment for substance abuse and accompanying mental health problems is beneficial, the researcher adds. The rationale behind this idea is that treatment could ease symptoms of depression or anxiety and improve patients' quality of life, or help them to understand the connection between these symptoms and their urge to use drugs or drink, or both. However, there have been no reviews of research to date providing evidence for or against this kind of treatment.

To fill the gap in knowledge, Hesse identified nine trials that compared integrated treatment to substance abuse treatment only for people with substance use problems and anxiety or depression.

While the studies used different methods and populations of patients, making it difficult to do a combined analysis, the results of integrated treatment for depression and substance abuse were "promising," Hesse writes.

Overall, integrated treatment produced a higher percentage of days abstinent, and a tendency for level of depressive symptoms to be lower and for more patients to stay in treatment retention.

On the other hand, his review of the evidence found little backing for integrated treatment for substance abuse and anxiety. In fact, he notes, "several studies report that outcomes for integrated treatment produced worse results than treatment that focused on substance use disorders alone."

The reason why integrated substance abuse treatment works for depressed patients but not anxious ones is "a mystery," Hesse told Reuters Health in an interview. "These are two very close disorders."

Exposure treatment, in which a person is faced with a thing that triggers anxiety, has been shown to be an effective treatment for anxiety, he added, but this approach may not work for someone who also has alcohol or drug problems. "Psychotherapy may actually stir up some uncomfortable feelings that trigger again the escape response," he explained, pushing the person to return to using drugs or alcohol.

"What I would recommend from clinical experience and from the rest of the research is to wait for a while until the patient feels very comfortable that he is able to cope with the drug urges or the alcohol craving and to proceed with the course of psychotherapy," Hesse added.

The researcher said he hopes the review will help increase awareness that, with depression at least, integrated treatment can help patients with substance use problems. However, he added, more research needs to be done on the topic, and to search out effective ways to treat people with anxiety and substance abuse.