Clustering and drivers of symptoms observed at week six after antidepressant treatment in depressed outpatients

Abstract

Background: Depressive symptoms remaining after antidepressant treatment increase the risk of relapse and recurrence. We aimed to analyze the distribution and main drivers of remaining symptoms in patients with a major depressive episode.

Methods: Two independent samples of 8,229 and 5,926 patients from two large naturalistic studies were retrospectively analyzed. DSM-IV criteria for major depressive episodes were assessed during two face-to-face visits with clinicians: before the prescription of a new antidepressant, and after 6 weeks of treatment. The Hospital Anxiety and Depression Scale (HADS) was used to assess baseline severity of anxiety and depression.

Results: In both samples, two clusters of remaining symptoms were observed. The first cluster encompassed symptoms related to a negative emotional and cognitive bias and was specifically driven by the baseline severity of depression. The second cluster encompassed neurovegetative symptoms and was specifically driven by the baseline severity of anxiety.

Conclusions: The baseline anxiety-depressive balance of patients could be considered to adapt the treatment, focusing on emotional and cognitive symptoms with patients with high baseline severity of depression, and neurovegetative symptoms with patients with high baseline anxiety severity.

Keywords: anxiety; cognitive; depression; emotional; residual symptoms.

Figure 1.

Schematic representation of a PCA of remaining depressive symptoms after 6 weeks of treatment in two independent samples (Sample 1, n = 7,809 and Sample 2, n = 5,473) and the role of depressive versus anxious symptoms as drivers of each cluster. β: standardized regression coefficients; DSM: Diagnostic and Statistical Manual of Mental Disorders; Ev: explained variance; HADS: Hospital Anxiety and Depression Scale; HADS-D*: prediction of factor 1 loading score (PCA) by depression baseline score (HADS) adjusted for anxiety baseline score (HADS), age, gender, length of current episode, number of past episodes and type of antidepressant treatment; HADS-A**: prediction of factor 2 loading score (PCA) by anxiety baseline score (HADS) adjusted for depression baseline score (HADS), age, gender, length of current episode, number of past episodes and type of antidepressant treatment; p: p value; PCA: Principal Component Analysis; s1: depressed mood (DSM-IV); s2: diminished interest (DSM-IV); s3: appetite disturbance (DSM-IV); s4: sleep disturbances (DSM-IV); s5: psychomotor disturbance (DSM-IV); s6: fatigue (DSM-IV); s7: worthlessness (DSM-IV); s8: diminished ability to think (DSM-IV); s9: suicidal thoughts (DSM-IV).