Adherence Issues with Antidepressants in Bipolar Patients

Bipolar patients are among the most difficult to treat, in part because mania is alluring and in part because they are often poor historians. As with any patient who must take medication for a chronic condition, bipolar patients’ adherence rates generally decline over time. About two-thirds of bipolar patients take more than 1 medication for this condition, and an antidepressant is often one component of the drug regimen.

Researchers from the University of Dresden in Germany recently looked at bipolar patients and the effect a patient’s mood has on adherence to antidepressants. Their work, published in the December 2013 issue of the International Journal of Bipolar Disorders, indicates that individuals who have bipolar disorder adjust their medications often but that mood seems not to be a driver.

The researchers enrolled 144 patients who had taken an antidepressant for at least 100 days. Of these patients, 111were also taking a mood stabilizer. The patients self-reported the medication dosage they took each day and also rated their moods. The researchers measured serial regularity in daily dosage. They also tracked drug holidays (missing 3 or more consecutive days).

Patients missed all antidepressant doses on fewer than 20% of days overall, but the researchers found that patients self-adjusted their antidepressant dosage often. Of patients in the study, 41% took drug holidays.

Patients who had the highest pill burden were more likely to skip antidepressant doses than others. Patients with active depression were also more likely to skip doses.

The researchers found no link between mood and dose adjustments.

The fact that patients self-reported their medication intake was both a limitation (patients could misrepresent their actual drug intake) and a strength (most other studies use surrogate markers) of the study.

The researchers conclude that although most patients don’t omit antidepressant doses on whole days, they do skip doses for 1 day or less often. With regard to the many patients who took drug holidays, the researchers expressed a concern that abrupt discontinuation of all classes of antidepressants, and especially short-acting serotonin uptake inhibitors, may trigger withdrawal reactions.