Medication non-adherence high in people with bipolar disorder

Key takeaways:

• More than half of people with bipolar disorder had at least one non-dispensed prescription mood stabilizer or antipsychotic.
• Nearly one-third of the cohort did not adhere to at least 20% of their medications.

More than half of people with bipolar disorder in Finland did not have at least one of their mood stabilizers or antipsychotic prescriptions dispensed, according to findings published in the Journal of Affective Disorders.

Jonne Lintunen, MD, PhD, of the department of forensic psychiatry at the University of Eastern Finland Niuvanniemi Hospital in Kuopio, Finland, and colleagues identified people with bipolar disorder who had mood stabilizers or antipsychotics prescribed between 2015 and 2018 and were listed in any of four national registers: the Hospital Discharge Register, the Sickness Absence Register, the Specialized Outpatient Care Register and the Disability Pension Register.

The researchers evaluated whether each medication was dispensed within 1 year if prescribed from 2015 to 2016 or within 2 years if prescribed from 2017 to 2019.

Among 33,131 people with bipolar disorder who were prescribed medication during the study period, 59.1% had at least one medication that was not dispensed. Additionally, 31% of people did not have at least 20% of their prescriptions filled during the study period.

Of 20,490 (61.8%) people who were prescribed at least one mood stabilizer from 2015 to 2018, 13.7% of these prescriptions were not dispensed. Most people (n = 29,349; 88.6%) were prescribed antipsychotics, 16% of which were not dispensed.

Adjusted analyses revealed non-adherence was more likely with female sex (adjusted OR = 1.08; 95% CI, 1.03-1.13), use of benzodiazepines (aOR = 1.62; 95% CI, 1.54-1.7) or antidepressants (aOR = 1.23; 95% CI, 1.17-1.29), personality disorders (aOR = 1.09; 95% CI, 1.02-1.15), cardiovascular disease (aOR = 1.06; 95% CI, 1-1.12) and diabetes (aOR = 1.21; 95% CI, 1.1-1.33). Further, non-adherence risk was greater in those aged younger than 25 years (aOR = 2.16; 95% CI, 1.96-2.39), bipolar disorder diagnosis within 3 years (aOR = 2.13; 95% CI, 1.98-2.28) and having been hospitalized for bipolar disorder at least four times (aOR = 2.36; 95% CI, 2.16-2.59).

“The high proportion of non-adherent patients is alarming since non-adherence is a well-known risk factor for poor clinical outcomes in bipolar disorder,” Lintunen and colleagues wrote. “Therefore, more attention should be given to the reasons why patients choose not to use their medications. Especially young patients, patients with recently diagnosed bipolar disorder, those with comorbidities and those who have had multiple psychiatric hospitalizations should be followed closely.”