Substance use disorders hamper bipolar medication adherence
MedWire News: Patients with bipolar disorder and current substance use disorder (SUD) have poor medication adherence and negative attitudes towards medications, conclude US researchers who recommend achieving substance use remission to improve outcomes.
High rates of medication non-adherence have been demonstrated in bipolar disorder patients with comorbid SUDs. Moreover, there is evidence to suggest that varying SUD histories - no, current, and past SUD history - have specific profiles that must be considered in research and treatment settings.
To investigate further, Christian Teter, from the University of New England, Portland, Maine, USA, and colleagues studied 26 bipolar I disorder patients with no history of SUD (BD-NH), 19 with a past history of SUD (BD-PH), and 9 with current SUD (BD-C).
The patients completed face-to-face interviews, psychiatric symptom scales, and were administered the 10-item version of the Drug Attitude Inventory (DAI). For each patient, the standardized medication adherence ratio (SMAR) was calculated by dividing the medication dose taken by the medication dose prescribed.
In all, 55.6%of BD-C patients had an alcohol-only SUD and the remaining 44.4% had a drug-only SUD. Specific SUDs among BD-PH were alcohol-only in 36.8%, drug-only in 21.1%, and both alcohol and drug in 42.1%.
BD-C patients had significantly higher scores on the Young Mania Rating Scale than either BD-NH or BD-PH patients, at means of 36.78 versus 24.85 and 24.84, respectively, the team notes in the journal Psychiatry Research.
Analysis revealed that BD-C patients had significantly lower rates of medication adherence than BD-PH and BD-NH patients, at mean SMARs of 0.70 versus 0.97 and 0.90, respectively. The differences remained significant after taking into account numerous independent variables. The most commonly cited reasons for lifetime medication non-adherence were medication adverse effects.
Adherent patients had significantly higher mean DAI scores than non-adherent patients, at +5.3 versus -0.25. Significantly more BD-C patients reported negative? DAI scores than BD-NH and BD-PH patients. For example, 100% of BD-C patients reported that "medications make me feel tired and sluggish," compared with just 61.5% of BD-NH and 52.6% of BD-PH patients.
The team concludes: "A targeted approach for providing education to patients with BD on the benefits of pharmacotherapy in specific patient subgroups (eg, current substance users, patients with negative attitudes concerning medications) could be a helpful component of treatment."
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By Liam Davenport