Alcohol use disorder (AUD) and bipolar disorder (BD) are commonly co-occurring conditions associated with more negative outcomes.1 Of all psychiatric conditions, BD has one of the highest rates of comorbid substance use disorder (SUD).2 While prevalence estimates vary, one study found that as many as 60.7% of people with type 1 BD (BD-1) had a lifetime diagnosis of an SUD, including 46.2% with AUD.2 In fact, the most commonly reported substance of abuse in BD is alcohol.3
“There is a higher frequency of SUD among psychiatric patients compared to the general population, but the association is highest among people with BD,” commented Ihsan Salloum, MD, MPH, professor of psychiatry and chief of the Division of Substance and Alcohol Abuse, Department of Psychiatry and Behavioral Sciences, University of Miami Miller School of Medicine.
The comorbidity has a “bidirectional negative impact,” with SUD increasing the severity of symptom presentation and influencing treatment adherence in BD, as well as the manifestation and course of the disorder; conversely, BD confers vulnerability for developing SUDs and relapse to SUDs.4 Moreover, SUDs can create diagnostic obfuscation leading to delayed recognition, diagnosis, and effective treatment of BD.
Bipolar disorder is associated with a very high suicide rate.5 Similarly, alcohol drives suicides even in people without BD, with approximately one-quarter of suicides associated with alcohol use.6 The elevated risk of suicide in both populations makes the comorbidity particularly dangerous.
“Alcohol increases impulsivity in bipolar disorder and can also increase suicide attempts, whether or not they are successful,” said Wilfrid Noel Raby, MD, PhD, assistant clinical professor of psychiatry, Columbia University College of Physicians and Surgeons, and a research psychiatrist at the New York State Psychiatric Institute.
“The comorbidity of BD and AUD is one of the significant issues for practitioners treating patients with these conditions,” he told Psychiatry Advisor.
Potential Mechanisms of Comorbidity
“There are several hypotheses for the high comorbidity between BD and AUD,” Dr Salloum told Psychiatry Advisor.
BD may be a risk factor for SUD.7 Conversely, symptoms of BD may be triggered and emerge during either chronic alcohol intoxication or withdrawal.7 Alcohol use and withdrawal may affect the same neurotransmitters involved in BD, causing one disorder to change the clinical course of the other.7
Common genetic factors may also be implicated.8 A positive family history of BD or alcoholism is an important risk factor for offspring.7
One of the most compelling hypotheses for the comorbidity is that individuals with BD are self-medicating their symptoms. “Initially, patients with BD may serendipitously discover a drug or drink and find it helpful. Stimulants may calm them, cannabis may relieve racing thoughts, and alcohol may keep irritable mania at bay,” Dr Raby observed.
However, “the initial leverage breaks, and now there is a situation in which the vicious cycle of intoxication and withdrawal worsens,” he said.
“Drinking first thing in the morning becomes necessary because withdrawal sets in, immediately worsening any symptoms of depression or mania that might be present,” he explained.
It is essential to distinguish independent (primary) mood disorders from substance-induced (secondary) mood disorders, which can be very challenging.9
“Find out if there is a family history of alcohol or drug dependence as well as a family history of mood disorders or other forms of psychiatric illness,” Dr Raby advised.
Dr Salloum added that many “treatment-resistant” patients with BD may actually have a substance abuse problem and should be assessed accordingly.
In a patient presenting with alcohol dependence, a comprehensive psychiatric history establishes whether mood symptoms are present and have occurred before or during substance use.9 Conversely, in a patient presenting with complaints of depression, anxiety, or insomnia, a good history of alcohol and substance use is crucial.9
Additional clues that suggest the presence of alcohol or drug use underlying psychiatric complaints include a past or family history of substance abuse, co-occurring or past medical conditions associated with alcohol or substance use, complaints of chronic pain, multiple relationship problems, numerous job changes, and legal difficulties.9