Personality disorders in patients with winter depression

Area of Science:

• Psychiatry
• Clinical Psychology

Background:

• Seasonal Affective Disorder (SAD) is a mood disorder characterized by depressive episodes related to seasonal changes.
• Previous research suggests potential links between personality disorders and mood disorders, but specific patterns in SAD require further investigation.

Purpose of the Study:

• To investigate the prevalence and patterns of personality disorders (PDs) in patients diagnosed with winter-type Seasonal Affective Disorder (SAD).
• To compare PD patterns in SAD patients with those reported for non-SAD major depression.
• To explore the relationship between SAD severity and dimensional measures of PD.

Main Methods:

• A sample of 66 patients meeting criteria for winter SAD or subsyndromal SAD were assessed.
• The Structured Interview for DSM-III-R Personality Disorders (SIDP-R) was administered during a non-depressed state.
• Multiple regression analyses were used to examine associations between SAD severity and PD measures.

Main Results:

• Twenty-three percent of SAD patients met criteria for at least one PD diagnosis.
• Cluster C PDs were most prevalent (18%), followed by Cluster B (12%) and Cluster A (5%).
• Dimensional measures indicated higher PD criteria counts for Cluster C disorders compared to other clusters.
• No significant association was found between SAD lifetime severity and dimensional PD measures.

Conclusions:

• The pattern of PDs in winter SAD patients resembles that of outpatients with non-SAD major depression.
• These findings support the hypothesis that SAD and major depression are distinct conditions with independent etiologies.