Poor Adherence to Oral Psychiatric Medication in Adults with Bipolar Disorder: The Psychiatrist May have More Influence than in Other Severe Mental Illnesses.

Objective

Medication adherence in bipolar disorder (BD) may be influenced by 6 selfreported dimensions: 1) high/low psychological reactance, 2) high/low internal healthlocus of control (HLOC), 3) high/low doctor HLOC, 4) pharmacophobia, 5) pharmacophilia, and 6) skepticism about a specific medication. This study in Spain, Argentina, and Venezuela included 142 outpatients with BD prescribed 320 psychiatric medications and 1230 other psychiatric outpatients prescribed 2134 medications.

Methods

Logistic regression models included adherence for each psychiatric medication, measured by the Sidorkiewicz Adherence Tool as the dependent variable. The models provided adjusted odds ratios (ORs) of dichotomous independent variables: clinical variables and 6 self-reported dimensions.

Results

ORs significant in both groups were: 1) high doctor HLOC (OR=1.87 in BD, OR=1.25 in other patients), 2) high psychological reactance (respectively OR=0.572, OR=0.798), 3) pharmacophobia (respectively OR=0.361, OR=0.614), and 4) skepticism about a specific medication (respectively OR=0.300, OR=0.556). Two ORs were only significant in BD patients: medication duration > 1 year (OR=0.449), and extreme polypharmacy (OR=2.49). The study included 104 BD patients prescribed 122 mood stabilizers and 136 other patients prescribed 140 mood stabilizers. Two ORs were significant for mood stabilizer adherence only in BD patients: high doctor HLOC and skepticism (respective ORs=2.38, OR=0.390). The study included 87 BD patients prescribed 97 antipsychotics and 417 other patients prescribed 458 antipsychotics. Four ORs were significant for antipsychotic adherence only in the BD group.

Conclusions

Future studies of adherence to all/specific medications should explore the specific city/commonality of these dimensions, particularly doctor HLOC, in BD versus other psychiatric patients. (Neuropsychopharmacol Hung 2021; 23(4): 347-362).