The effect of temperament and character on response to selective serotonin reuptake inhibitors in panic disorder
Marchesi C, Cantoni A, Fonto S, Giannelli MR, Maggini C;
Commented by , 27 Sep 2006
Background
Personality disorders as well as various personality characteristics may be related to poor response to treatment in panic disorder (PD).
Aims of the study
To verify whether the temperament and character dimensions assessed with the Temperament and Character Inventory (TCI) are related to poor outcome in patients presenting with PD.
Method
Treatment outcome was assessed monthly over one year in 71 patients with PD treated with a selective serotonin reuptake inhibitor (citalopram or paroxetine). To evaluate the effect of temperament and character on outcome, participants were assessed with the TCI prior to treatment.
Results
After controlling for the effect of all confounding variables, including in particular duration of the disorder, severity of anxiety symptoms, and co-morbid depressive and anxiety disorders, only self-directedness (SD) showed a predictive value on outcome of treatment.
Professor Pull's comments
The efficacy of various SSRIs as well as the efficacy of cognitive-behaviour therapy (CBT) for treating PD has been established in numerous randomized controlled trials. However, a substantial proportion of patients do not respond to either pharmacotherapy or CBT alone or to a combination of pharmacotherapy and CBT.
Various personality characteristics and/or personality disorders have long been suspected to be one of the main factors involved in good vs. poor treatment outcome.
Personality and personality pathology may be investigated using either a categorical or a dimensional approach. The categorical approach is based upon the assessment of personality disorders as defined in DSM-IV-TR or ICD-10. The dimensional approach is based upon the assessment of personality characteristics that have been identified through factor analytic and related statistical methods of personality questionnaires.
Among the variety of alternative dimensional models, Cloninger’s psychobiological model has received widespread attention in recent years. The model defines four dimensions of temperament and three dimensions of character. The seven dimensions are assessed using a questionnaire, the Temperament and Character Inventory (TCI) (ref. 1, ref. 2).
In Cloninger’s model, temperament refers to automatic emotional responses to experience that are moderately heritable (i.e. genetic, biological) and stable throughout life. The four measured temperament dimensions are Novelty Seeking (NS), Harm Avoidance (HA), Reward Dependence (RD), and Persistence (PS).
According to Cloninger, character refers to self-concepts and individual differences in goals and values, which influence voluntary choices, intentions, the meaning and salience of what is experienced in life. Differences in character are moderately influenced by socio-cultural learning and mature in progressive steps throughout life.
Character takes into account the psychology of the development of personality. The three measured character dimensions are Self-Directedness (SD), Cooperativeness (CO), and Self-Transcendence (ST).
Self-directedness (SD) is a dimension of character. As defined by Cloninger, SD quantifies the extent to which an individual is responsible, goal-oriented, resourceful, reliable, and self-confident. SD evaluates five patient’s characteristics:
- acceptance of responsibility for one’s own choices instead of blaming other people and circumstances,
- identification of individually valued goals and purpose vs. lack of goal direction,
- development of skills and confidence in solving problems (resourcefulness) vs. inertia,
- self-acceptance of own limitations vs. self-striving, v) maintenance of behavioural habit congruent with goals and values vs. personal distrust.
After controlling for the effect of all the confounding variables, the results of the study discussed here show that only SD had a predictive value on outcome of treatment. Patients with low pre-treatment levels of SD were less likely to achieved remission. More specifically, one of the five characteristics included in SD, i.e. the self-acceptance vs. self-striving dimension of SD, was found to influence the response to treatment.
Patients characterized by low pre-treatment levels of self-acceptance less likely achieved complete remission.
Altogether, the results from the current study suggest that medication treatment is less effective in PD patients unable to accept themselves as they are, to accept their limitations and to admit their faults.
In spite of many limitations, which are described in detail by the authors, this is an interesting and innovating study. First, the results confirm that outcome of treatment for panic disorder may be related to certain aspects of personality. Second, linking outcome of treatment for panic disorder to a dimension of personality is in line with recent trends to focus attention on the dimensional model of personality. Third, the findings give support to at least some aspects of Cloninger’s model of temperament and character.
References
1. Cloninger CR. The tridimensional personality questionnaire. St Louis, MO: Department of Psychiatry, Washington University School of Medicine, 1987
2. Cloninger CR, Svrakic DM, Przybeck TR. A psychobiological model of temperament and character. Archives of General Psychiatry 1993; 50 (12); 975-990