Temperament traits and remission of depression: A naturalistic six-month longitudinal study

The aim of this naturalistic longitudinal study was to add evidence regarding the potential of Cloninger's temperament traits (novelty seeking, harm avoidance, reward dependence and persistence) for predicting the effect of pharmacological treatment on the rates of therapeutic response and remission.

The study was based on 200 outpatients with unipolar depressive disorders of different severity and course of illness, and extended up to 6 months of follow-up. Patients were assessed in their temperament with the Tridimensional Personality Questionnaire (TPQ) and their condition was classified (in course and severity) according to the International Classification of Diseases, Tenth revision (ICD-10) diagnostic criteria for research. Patients were blindly rated (concerning other predicting variables) on the improved Clinical Global Impression-Severity scale for depression (iCGI-S) at baseline, 6 weeks, 3 months and 6 months. Outcome measures at the last observation carried forward were therapeutic response (reduction of ≥50% in the last iCGI-S) and remission (last iCGI-S = 0), which were available for 187 patients.

Remission was independently and directly associated with length of follow-up, and inversely with the baseline iCGI-S score and harm avoidance (patients in the high tertile had a 2.7 likelihood of non-remission in comparison with those in the low tertile); persistence was found to have a complex, V-shape relationship with remission. Within a sub-sample of more severe cases (n = 118), having higher harm avoidance scores, a more favorable outcome was associated with higher reward dependence and the non-smoking condition.

With a naturalistic, non-experimental design, the sample may not be representative of the general population.

Temperament traits may help predict outcome in patients treated for depression.