Depressive personality traits and dysthymia: a commentary on Ryder and Bagby

Depressive vulnerability in women with Alzheimer's disease: Relationship with personality traits and abnormal personality dimensions

BACKGROUND

This study sought to determine the evaluation of current and pre-morbid depressive vulnerability dimensions in Alzheimer's disease. Sidney Blatt´s personality developmental perspective, the Five-Factor model and Axis II personality disorders were taken as references.

METHODS

The study was conducted with two groups which were assessed using the Depressive Experiences Questionnaire, the NEO-FFI and the Personality Diagnostic Questionnaire-4+, in the form of individual interview sessions. Current personality measure: Alzheimer's disease Group, consisting of 44 female participants (M_Age= 81.36 years); Pre-morbid personality measure: Alzheimer's disease Group Informants (n = 40).

RESULTS

Self-Criticism personality vulnerability is a general indicator of psychopathology. In pre-morbidity, Neuroticism (β = 0.41), Agreeableness (β = -0.63) and Conscientiousness (β = -0.08) predicted Self-Criticism, explaining 64% of the variance; additionally, Self-Criticism (β = 0.72) and Neediness (β = 2.05) predicted the PDQ-4+ total, explaining 58% of the variance. In terms of current personality, the PDQ-4+ total was predicted by Self-Criticism (β = 0.55), explaining 30% of the variance.

LIMITATIONS

The small size of the samples, especially since it is difficult to access individuals diagnosed with AD at the onset or in its early stages; measuring personality changes by means of retrospective assessment by proxies may have introduced some memory bias.

CONCLUSIONS

These findings are relevant to research relating depressive vulnerability to personality traits and psychopathology in Alzheimer's disease.

Depressive personality disorder: a critical overview

Depressive personality disorder (DPD), which has a long tradition in psychiatry, currently resides in Appendix B ("Disorders for Further Study") of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. After a brief outline of this history, the authors review empirical research on DPD using the Robins and Guze criteria (discussed later) for diagnostic and clinical validity as a framework. Although DPD has unique features, the authors argue that this diagnosis can largely be subsumed under dysthymic disorder. As a result of diagnostic confusion, and of the small amount of research conducted in this area, recommendations for the assessment and treatment of DPD are necessarily speculative. The authors conclude that if personality disorders are maintained as categoric constructs, DPD may best be understood as a subtype of dysthymic disorder. A more radical solution would be to conceptualize DPD, along with the other personality disorders, as extreme positions along dimensional continua.

Personality disorder and Axis I psychopathology: the problematic boundary of Axis I and Axis II

The confusion of personality disorders with Axis I disorders can be traced in part to inadequacies of assessment instruments and diagnostic criterion sets. However, it also reflects the absence of adequate conceptualization. If Axis I continues to include early onset, chronic impairments that characterize everyday functioning, then there is unlikely to be a clear or meaningful distinction. Inherent and unique to personality disorders is that they concern a person's sense of self and identity. They are disorders of everyday functioning. Personality disorders have an early onset, characterize everyday functioning, and relate closely to personality functioning evident within the general population; Axis I disorders, in contrast, have an onset throughout adult life, are episodic, and are readily distinguishable from normal personality functioning.

Chronic, low-grade depression in a nonclinical sample: depressive personality or dysthymia?

Depressive personality disorder (DPD) is being considered for inclusion in future editions of the Diagnostic and Statistical Manual of Mental Disorders (DSM). However, there is substantial conceptual and empirical overlap between DPD and dysthymic disorder (Dysthymia) criteria, suggesting that these two constructs may not be distinct. Confirmatory factor analysis of the DPD traits and dysthymia symptoms in a large, nonclinical sample (N = 368) indicated that a two-factor model was a better fit than a one-factor model. However, binary diagnostic analysis revealed that over half of the individuals meeting criteria for DPD also met criteria for dysthymia and that the best-fitting model allowed the psychological symptoms of dysthymia to load on both DPD and dysthymia latent factors. All of the individuals with DPD alone failed to meet criteria for dysthymia because they did not report chronic depressed mood. Our results suggest that although DPD is not synonymous with Dysthymia, it may be a milder subtype.