Background: Depression is prevalent in people with type 2 diabetes and affects both glycemic control and overall quality of life. The aim of this trial was to evaluate the effect of the antidepressant paroxetine on metabolic control, quality of life and mental well-being in mildly depressed women with type 2 diabetes.
Methods: We randomised 15 mildly depressed women with non-optimally controlled type 2 diabetes to a 10-week single-blind treatment with either paroxetine 20 mg per day or placebo. Primary efficacy measurements were glycemic control and quality of life. Glycosylated hemoglobin A1c (GHbA1c) was used as a measure of glycemic control. Quality of life was evaluated using RAND-36. Mental state was assessed using two clinician-rated scoring instruments, Hamilton's Anxiety Scale (HAM-A) and Montgomery-Asberg's Depression Rating Scale (MADRS), and a patient-rated scoring instrument, Beck's Depression Inventory (BDI).
Results: At the end of the study no significant difference between groups in improvement of quality of life was found. A trend towards a superior improvement in glycemic control was found in the paroxetine group (p = 0.08). A superior increase in sex-hormone-binding-globuline (SHBG) levels was evidenced in the paroxetine group (p = 0.01) as a sign of improved insulin sensitivity. There was also a trend for superior efficacy of paroxetine in investigator-rated anxiety and depression. This notion was supported by a trend for superior decrease of serum cortisol levels in the paroxetine group (p = 0.06).
Conclusion: Paroxetine has a beneficial effect on measures of insulin sensitivity and may improve glycemic control. Larger studies of longer duration are needed to verify the benefits of paroxetine in type 2 diabetes. While waiting for more conclusive evidence it seems sensible to augment standard care of type 2 diabetes with paroxetine even in patients who do not fulfil routine psychiatric criteria for initiation of antidepressant drug treatment.