An exploratory study of adolescent response to fluoxetine using psychological and biological predictors

Background. Not enough is known about predicting therapeutic response to serotoninspecific reuptake inhibitors, and specifically to fluoxetine. This exploratory study used psychological and biological markers for (retrospective) prediction of treatmentresponse to fluoxetine in depressed and/or anxious adolescents. Methods. Forty-one consecutive adolescent outpatients with a primary diagnosis of severe affective and/or anxiety disorders were assessed and treated with an open-label 8- week trial of fluoxetine. TypeDpersonality was assessed with the 14-item questionnaire, the DS14. In addition, TNFα, IL-6, and IL-1b were measured pre- and post-treatment. Results. There was an elevation of Type D personality in patients, compared to the adolescent population rate. Post-treatment, 44% of patients were classified as nonresponders; the relative risk of non-response for Type D personality patients was 2.8. Binary logistic regression predicting response vs. non-response showed a contribution of initial TNFα levels as well as Type D personality to non-response. Conclusions. In this exploratory study, the most significant contributor to nonresponse was Type D personality. However, the measurement of Type D was not prospective, and thus may be confounded with psychiatric morbidity. The measurement of personality in psychiatric settings may contribute to the understanding of treatment response and have clinical utility.