30th ECNP, 1-5 SEPTEMBER 2017, PARIS CG17P-0994

DYSTHYMIA AND DOUBLE DEPRESSION IN A MENTAL HEALTH UNIT

A. De la Cruz Dávila, I. Veiga Ramos, M.T. Ríos Vilas, C. Quinteiro Rouco.

BACKGROUND

The validity of dysthymia has been debated since it was introduced in DSM-III. Our objective is to further examine the concept of dysthymia in an outpatient sample, and to explore whether its constituents can be meaningfully apportioned. Approximately two-thirds of patients with personality disorders have suffered from at least one comorbid depressive episode [1], and depression is frequently associated with personality disorders [2] [3]. According to Iacoviello et al.[4], cluster B personality disturbance confers a risk for depressions of longer duration and increased severity, whereas cluster C significantly predicts symptomatic chronicity. On the other hand, there is considerably more biological evidence for a depressive type of personality and, furthermore, the work with affective temperaments developed by Akiskal and Akiskal [5] has provided some additional evidence for a dysthymic temperament. However, nowadays it still remains unclear how affective temperaments are related to depressive personality disorder.

AIM

The main objective of this research is to examine whether dysthymia demonstrates discriminant validity, and to study the conmorbidity between dysthymic disorder, depressive personality disorder, cluster B personality disorder and major depressive disorder (double depression).

METHODS AND RESULTS

40 patients attending the Mental Health Unit (Unidade de Saúde Mental) at Santiago de Compostela Area (Spain) were assessed by the Mini-International Neuropsychiatric Interview, and completed several self-report measures, in addition to a clinical assessment. Patients who reached criteria for dysthymic disorder were included. On the contrary, patients with a lifetime diagnosis of bipolar disorder (I or II) or schizoaffective disorder were excluded. Having done this, the characteristics of patients with dysthymic disorder and double depression were examined.

The total study population consisted of 40 patients that reached criteria for dysthymic disorder. All of them were women (100%). Among them, 10 (25%) reached the DSM-IV criteria for depressive personality disorder, 20 (50%) for double depression, and 8 (20%) for C type personality disorder. Moreover, 20 of them (50%) were diagnosed with other neuropsychiatric entities, of whom 9 (22,5%) reached criteria for fibromyalgia. The mean age of onset was 63,4 years, with standard deviation from the median of 10,07. There were two statystical modes in the studied population of 30 and 50 years old.

Dysthymia: diagnostic overlap Dysthymia comorbidity

20

18

16

14

12

10

8

6

4

Depressive personality dissorder Double depression

2

Personality dissorder "C" None

0 Number of patients Fibromyalgia Other neuropsychiatric entities None

CONCLUSIONS

A significant overlap has been found between dysthymic disorder, depressive personality disorder, cluster B personality disorder and major depressive disorder (double depression). Research findings show that dysthymic disorder is a heterogeneous diagnosis encompassing many different depressive conditions, therefore, there is no clear evidence of its validity as a diagnostic entity. As dysthymic disorder is a component of DSM-defined persistent depressive disorder, it limitates the identification of specific causative factors and also the preferential treatment modality. Despite of the high prevalence of this diagnostic entity in clinical practice, our knowledge about it is limitated. It will be necessary further research in the future to fully understand the complexity of this disorder.

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