Comorbidity of alcoholism and psychiatric disorders: an overview

Alcohol Research & Health, Spring, 2002 by Ismene L. Petrakis, Gerardo Gonzalez, Robert Rosenheck, John H. Krystal

Croop and colleagues (1995) studied the effects of naltrexone in more than 500 alcohol-dependent patients, including a large percentage of dually diagnosed patients simultaneously receiving medications for other comorbid mental disorders. The rate of adverse events in naltrexone-treated patients did not differ in patients with and without comorbid mental disorders. In another study, a chart review of 72 patients treated in an outpatient mental health clinic for major psychiatric illnesses, including schizophrenia, bipolar disorder, schizoaffective disorder, and comorbid alcohol dependence suggested that naltrexone can have a good clinical response as measured by treatment retention and alcohol consumption (Maxwell and Shinderman 2000).

Although this research offers promising evidence about the use of naltrexone in patients with comorbid psychiatric disorders, further research evaluating its efficacy; tolerability, and safety is warranted.

Acamprosate. Preclinical research on acamprosate suggests that it interacts with a receptor, or binding molecule, known as the N-methyl-D-aspartate (NMDA) receptor, for the brain chemical (i.e., neurotransmitter) glutamate. Interactions with other receptors are currently being studied. A series of placebo-controlled European studies involving more than 4,500 patients have indicated that detoxified patients treated with acamprosate were less likely to drop our of treatment and achieved higher rates of abstinence (Mason and Ownby 2000) than those on placebo. Researchers have hypothesized that acamprosate may help patients achieve abstinence at least partially by diminishing withdrawal symptoms (Mason and Ownby 2000). Although approval of acamprosate in the United States is still pending additional clinical trials, it is widely available in Europe. Additional studies will help to answer questions about the use of acamprosate in alcoholism treatment. Research establishing its efficacy was conducted in patients wi thout comorbid psychiatric disorders.

Antidepressants. The relationship between depression and alcoholism is complex because of overlapping symptoms, common neurobiological abnormalities (Pettinati et al. 2000a), and similar treatments (pharmacological and psychosocial). Two classes of antidepressants--the selective seroronin reuptake inhibitors (SSRIs), which affect the production and/or absorption of the neurotransmitter serotonin, and the tricyclic antidepressants (TCAs)--have been evaluated in patients with comorbid depression and alcohol use. The TCAs, including desipramine and imipramine, have been found effective in treating depression in alcoholics (Kranzler and Rounsaville 1998), but there is no consistent evidence that they are effective in decreasing alcohol consumption. With these mixed results and considering the potential for overdose, the use of TCAs in alcohol-abusing patients may be unwise.

The SSRIs, because they have fewer serious side effects than the older antidepressants, have become the first line of treatment for depressive disorders (Berman and Charney 1999). Researchers have hypothesized that the SSRIs may directly affect alcohol consumption (e.g., by preventing relapse to alcohol use during stress) (Sellers et al. 1994). This hypothesis is supported by some preclinical data and by some clinical data, which have shown that SSRIs are effective in reducing alcohol use in depressed people but nor in reducing alcohol use in people without depression. Several studies have shown that SSRIs are effective in decreasing alcohol use (Cornelius et al. 1995; 1997 a, b) as well as depressive symptoms (Cornelius et al. 1997 a, b; Roy 1998) in patients with comorbid alcoholism and depression. However, SSRIs may have a different effect depending on the subtype of alcoholic (Kranzler et al. 1996), and recent literature suggests that the SSRIs may be effective only in certain subtypes of depressed alcoholics (Pettinati et al. 2000b) . A small open-label study (i.e., a study in which all participants receive the experimental treatment) has shown that SSRIs may be effective in patients with comorbid PTSD and alcoholism (Brady et al. 1995).