Most people familiar with public health issues are aware of the challenges posed by “dual diagnosis” patients — those with both a psychiatric diagnosis and a substance abuse diagnosis. But the special case of addicted bipolar disorder patients is particularly problematic. Writing in the August issue of Current Psychiatry, Bryan K. Tolliver lists the severe outcomes that plague the victims of bipolar disorder who are also substance abusers: “Poor treatment compliance, longer and more frequent mood episodes, more mixed episodes, more hospitalizations, more suicide attempts.”

In Bipolar Disorders, Cassidy and coworkers conclude that lifetime rates of substance abuse in test populations of bipolar patients can run as high as 48.5% for alcohol and 44% for drugs. In addition, a study published in Psychiatric Services, which sampled almost 3,000 veterans diagnosed with bipolar disorder, found more evidence for troubling correlations: “Patients diagnosed as having both an alcohol use disorder and polysubstance dependence and who also were separated from their spouse or partner had a 100% risk of psychiatric hospitalization [Italics added]; risk of psychiatric hospitalization decreased to 52% if the patients were not separated from their partner.”

Not a pretty picture.

What is the link between these two seemingly disparate conditions? Why do bipolar disorder patients abuse alcohol and other drugs at rates far higher than other populations of psychiatric patients, or the population at large? In his article, professor Tolliver, who is with the clinical neuroscience division at the Medical University of South Carolina, lists several theories, along with their limitations:

—Drug abuse as self-medication for an existing bipolar disorder. This explanation is often invoked to explain the very high rates of cigarette smoking among schizophrenics. However, it fails to account for the fact that manic depressives often use stimulant drugs when they are manic, and sedating drugs when they are depressed, rather than the other way around.

—Co-morbidity as the result of common genetic risk factors. A compelling hypothesis, but, according to Tolliver, specific evidence in the form of genetic linkage studies is lacking.

—Drug abuse as a symptom of bipolar disorder. The problem with this explanation is simply that most bipolar disorder patients do not have drug problems. And, in those that do, there is a “poor correlation of onset.”

—Drug abuse as a trigger for bipolar disorder. In this case, the counter-evidence is that “emergence of mania before substance use disorder is common.” However, when the onset of mania precedes the development of drug abuse, particularly during adolescence, it “may predict a more severe course of both illnesses,” writes Tolliver.

—Misdiagnosis based on common symptoms and “poor diagnostic boundaries.” But in this case we find that a high rate of drug abuse is common in longitudinal studies of patients initially hospitalized for mania.

There are other diagnostic problems. For example, procedures for bipolar clinical studies and drug trials often mean that patients with drug problems are routinely excluded. Similarly, patients with serious mental illnesses are themselves excluded from randomized controlled trials in substance abuse treatment studies.

Another common problem is that “denial of illness is a critical symptom that may fluctuate with disease course in both disorders.”  Furthermore, there can be clinical confusion when bipolar disorder “is overdiagnosed in persons engaged in active substance abuse or experiencing withdrawal.”

There is no FDA-approved pharmaceutical treatment for co-occurring bipolar disorder and substance abuse.  To make matters worse, drug abuse in bipolar disorder patients, especially rapid cyclers, usually predicts that the patient will have a poor response to lithium, the most common treatment for bipolar disorder.

Limited drug studies have been done, but thus far, few compounds have emerged as heavyweight candidates. Depakote,  (divalproex sodium), which is another common treatment for the manic phase of bipolar disorder, decreased the number of heavy drinking days in dual diagnosis patients when combined with lithium. But in a different study, the group differences petered out after six months. (Lithium alone was associated with decreases in cannabis use.) Carbamazepine, an anti-convulsant with a mixed history when used for cocaine dependence, seemed to slow cocaine use in one study of bipolar disorder patients. And Seroquel (Quetiapine), a controversial drug used in the treatment of schizophrenia, lessened some symptoms of depression. Finally, Revia (naltrexone), in a 12-week study of alcoholic patients with diagnosed with bipolar disorder, led to modest decreases in the number of drinking days.

None of these results can be characterized as a breakthrough, to say the least.  Integrated group therapy, designed specifically for dual diagnosis patients, has shown promise, compared to standard group drug counseling. But the reality is that additional research on treatment avenues is urgently needed for this most challenging of dual diagnosis disorders.

Resources

Tolliver, BK (2010). Bipolar Disorder and Substance Abuse. Current Psychiatry, 9 (8).

Cassidy F, Ahearn EP, & Carroll BJ (2001). Substance abuse in bipolar disorder. Bipolar disorders, 3 (4), 181-8 PMID: 11552957

Hoblyn JC, Balt SL, Woodard SA, & Brooks JO 3rd (2009). Substance use disorders as risk factors for psychiatric hospitalization in bipolar disorder. Psychiatric services (Washington, D.C.), 60 (1), 50-5 PMID: 19114570