Predicting response to antidepressant treatment and electroconvulsive therapy in major depression based on early improvement

Aim: New evidence suggests that the eficacy of antidepressants can be observed from the first weeks of treatment and this early response predicts later response. The purpose of this study is to investigate if the partial response in the first week predicts the response at the end of treatment in patients with major depresive disorder who are treated with either antidepressant medication or electroconvulsive therapyMethod: Inpatients with major depressive disorder, treated with antidepressant medication (n= 52) or with electoconvulsive therapy (ECT) (n=48) were recruited for the study. The data were collected retrospectively to decide if the 25% decrease in the Hamilton Depression Rating Scale (HDRS) score at the first week of treatment predicts the 50% decrease at the third week using the validity analysis. The affect of various sociodemografic and clinical variables on the treatment response were assessed.Results: 25% decrease in the HDRS score in the first week of treatment predicted %50 decrease in the HDRS score in the third week with 78,3% positive predictive value, 62,1% negative predictive value, 62,1% sensitivity and 78,3% specifity for antidepressant medications and 88% positive predictive value, 52,2% negative predictive value, 66,7% sensitivity and 80% specifity for ECT. Number of previous hospitalizations, comorbid medical illness, number of depressive episodes, duration of illness and duration of current episode were releated with the treatment response.Conclusion: Treatment response in the first week predicted response in the third week with a high specifity and a high positive predictive value. Close monitoring of response from the first week of treatment may help clinician predict subsequent response.Key words: Antidepressant medications, electroconvulsive therapy, major depression, response, prediction