Weight gain with add-on second-generation antipsychotics in bipolar disorder: a naturalistic study

Area of Science:

• Psychiatry
• Pharmacology
• Clinical Research

Background:

• Bipolar disorder requires long-term management, often involving mood stabilizers.
• Second-generation antipsychotics (SGAs) are sometimes used as add-on therapy.
• Weight gain is a potential side effect of antipsychotic medications.

Purpose of the Study:

• To investigate the prevalence and magnitude of weight gain in bipolar disorder patients receiving SGAs as add-on treatment.
• To compare weight changes in patients on mood stabilizers alone versus those on add-on SGAs.

Main Methods:

• Retrospective analysis of the Swedish quality register for bipolar disorder (BipoläR).
• Comparison of 575 patients on add-on SGAs with 566 age- and sex-matched patients on mood stabilizers alone.
• Primary outcomes: change in body weight and BMI; secondary outcome: prevalence of ≥7% weight gain.

Main Results:

• Patients receiving add-on SGAs did not experience significantly more weight gain than the control group.
• No increased risk of clinically significant weight gain (≥7%) was observed in the SGA add-on group.
• Factors associated with weight gain included female sex, younger age, lower baseline BMI, and manic/hypomanic episodes.

Conclusions:

• Add-on treatment with SGAs to mood stabilizers in routine clinical practice for bipolar disorder is not associated with an overall increased risk of weight gain.
• Individual patient factors, rather than SGA add-on therapy itself, appear to be more predictive of weight gain.