An investigation of Temperament and Character Inventory items for predicting the response to paroxetine treatment in patients with major depressive disorder

Abstract

Background

Previous studies have reported associations between Temperament and Character Inventory (TCI) dimension scores and the response to treatment in patients with major depressive disorder (MDD). We aimed to determine which TCI items could predict the response to treatment with paroxetine in patients with MDD.

Methods

Seventy-three patients were enrolled in this study. The participants were treated with 10–40 mg/day of paroxetine for six weeks; they then completed the TCI. The Montgomery-Asberg Depression Rating Scale (MADRS) was used to evaluate the patients. The participants were divided into two groups (responders and non-responders). We used a chi-squared test to identify the 10 items with the strongest association with treatment response from among all 240 items on the TCI, and we used a multiple logistic regression analysis to confirm the validity of these 10 items.

Results

Among the TCI dimension scores, only the C score differed significantly between the two groups. We analyzed 10 models using each of the 10 best items. All the models significantly predicted treatment response. The TCI dimensions model also significantly predicted treatment response, but its predictive value was lower than those of the other 10 models.

Limitations

The responders included the early responders. The results lacked information about responders whose responses were not predicted by the logistic regression models and TCI items.

Conclusions

Some TCI items showed significant associations with the response to paroxetine treatment in the patients with MDD. Treatment response in patients with MDD may be predicted using only 10 items from the TCI.

Introduction

The Temperament and Character Inventory (TCI) is a psychological test that is frequently used to assess personality traits (Cloninger et al., 1993). This questionnaire consists of seven dimensions: four dimensions are related to temperament (novelty seeking [NS], harm avoidance [HA], reward dependence [RD], and persistence [P]), and three dimensions are related to character (self-directedness [SD], cooperativeness [C], and self-transcendence [ST]). Many studies have demonstrated relationships between the results of the TCI and certain mental conditions or disorders. In one study, newly enrolled university students completed the TCI, and researchers subsequently investigated the number of subjects who later committed suicide; the HA scores were higher in the subjects who committed suicide (Mitsui et al., 2013). Pawlak et al. (2013) reported that high NS and HA scores were risk factors for affective disorders.

Many previous studies have examined the relationships between major depressive disorder (MDD) or depression and scores on the TCI and its subscales. Several studies have reported that the high HA and low SD dimensions were associated with a depressed mood (Brown et al., 1992, Bayon et al., 1996, Cloninger et al., 1998, Hansenne et al., 1999, Naito et al., 2000, Richter et al., 2000, Farmer et al., 2003, Spittlehouse et al., 2010, Kaneda et al., 2011). Furthermore, many studies have suggested that of the seven TCI dimensions, high scores on the HA dimension are the most strongly correlated with a depressive state or MDD (Brown et al., 1992; Hansenne et al., 1999; Naito et al., 2000, Richter et al., 2000, Farmer et al., 2003, Spittlehouse et al., 2010, Kaneda et al., 2011). Therefore, MDD or a depressive state may be associated with the HA personality trait.

Previous studies have reported changes in TCI dimension scores after patients with MDD receive treatment (Black and Sheline, 1997, Richter et al., 2000, Corruble et al., 2002, Hirano et al., 2002, Abrams et al., 2004). The results of these studies showed that the HA score decreased significantly after drug treatment or in treatment responders, and some of the studies reported changes in the SD, C, and ST dimensions (Black and Sheline, 1997, Corruble et al., 2002, Hirano et al., 2002). Abrams et al. (2004) demonstrated that the HA score was positively associated with poor improvement after treatment in patients with MDD.

Thus, in patients with MDD, TCI results are closely related to MDD or depressive symptoms, and scores on specific dimensions of the TCI may be able to predict response to treatment in patients with MDD. These findings seem to be beneficial in clinical settings, but the TCI consists of 240 items; thus, patients may view completing this lengthy questionnaire as a burden. In the present study, we investigated which TCI items most strongly predicted the response to paroxetine treatment in patients with MDD.