Optimism and pessimism as predictors of initiating and ending an antidepressant medication treatment

The personality variables optimism and pessimism are potential risk factors for disorders commonly treated with antidepressants.

To evaluate optimism and pessimism as predictors of initiating and ending an antidepressant treatment.

Data consisted of 29,930 public sector employees with no record of diagnosed depression. Optimism and pessimism were measured using the Revised Life Orientation Test (LOT-R) at baseline. The data of purchases of antidepressants were from the national Drug Prescription Register.

During the mean follow-up of 4.4 years, 1681 participants initiated and of them 1288 ended an antidepressant treatment lasting at least 100 days. In the adjusted model, high optimism was associated with a lower likelihood of starting antidepressant medication treatment (hazard ratios, HR, 0.67, 95% CI 0.62-0.73) and a higher likelihood of stopping the treatment (HR = 1.18, 95% CI 1.08-1.30). High pessimism was associated with a higher likelihood of starting antidepressant medication treatment (HR = 1.27, 95% CI 1.16-1.38) and a lower likelihood of stopping it (HR = 0.89, 95% CI 0.80-0.98). These associations remained after optimism score was adjusted for pessimism and vice versa or those with symptoms of mental health problems at baseline were removed from the analyses.

Low optimism and high pessimism are independently associated with an increased likelihood of initiating antidepressant medication treatment, but with a decreased likelihood of ending it during the follow-up.