Effect of severity of depression on augmentation of antidepressant medication in young adults with depression.

BACKGROUND: Antipsychotics (AP) have been used to augment antidepressant (AD) medication in treatment-resistant depression. In this study we examined factors (including severity of depression and initial antidepressant) affecting AP augmentation, as well as which APs were initiated as augmentation in young adults.

METHODS: Data were extracted from Finnish nationwide registers. Of persons aged 18-29 years diagnosed with a depression during 2004-2017 we focused on incident AD users (who initiated AD 6 months before and after the diagnosis) whose severity level of depression was recorded (N = 21,966). AP augmentation was studied during 1 year after diagnosis of depression. Persons diagnosed with severe depression with psychotic features (n = 1486) were excluded from main analyses and analyzed separately.

RESULTS: Overall, 8.4% of new antidepressant users initiated AP augmentation. Risk of augmentation increased with severity of depression as 3.9%, 5.8%, and 14.0% of persons with mild, moderate, and severe depression, respectively, initiated augmentation. Male sex, comorbid anxiety and personality disorders, substance abuse and selfharm/suicide attempt were positively associated with augmentation. Compared to citalopram, use of tricyclic antidepressant, paroxetine and venlafaxine were associated with increased risk of augmentation, while use of bupropion was associated with a decreased risk. Quetiapine and risperidone were the most common APs used in augmentation. Among persons with severe depression with psychotic features, use of sertraline was associated with AP augmentation, whereas use of fluoxetine decreased risk of augmentation.

CONCLUSIONS: Use of APs as augmentation of AD therapy was common in severe depression. Comorbidities had only a small effect to augmentation, but selection of initial AD was more closely associated to risk of augmentation. Interestingly, use of bupropion decreased risk of augmentation, which warrants further studies, as well as the decrease in risk of augmentation when fluoxetine in case of psychotic depression was used.