Categorical and Dimensional Stability of Comorbid Personality Disorder Symptoms in DSM-IV Major Depressive Disorder: A Prospective Study

Objective: To investigate the categorical and dimensional temporal stability of Axis II personality disorders among depressive patients, and to determine whether variations in Axis I comorbid disorders or self-reported personality traits predict changes in researcher-assigned personality disorder symptoms.

Method: Patients with DSM-IV major depressive disorder (MDD) in the Vantaa Depression Study (N’ ‰=’ ‰269) were interviewed with the World Health Organization Schedules for Clinical Assessment in Neuropsychiatry, version 2.0, and the Structured Clinical Interview for DSM-III-R Axis II Disorders and were assessed with the 57-item Eysenck Personality Inventory at baseline, 6 months, and 18 months. Baseline interviews occurred between February 1, 1997, and May 31, 1998; follow-up interviews were 6 months and 18 months after baseline for each patient. Of the patients included in the study, 193 remained unipolar and could be interviewed at both follow-ups. The covariation of the severity of depression, anxiety, alcohol use, and reported neuroticism and extraversion with assigned personality disorder symptoms
was investigated by using general estimation equations.

Results: The diagnosis of personality disorder persisted at all time points in about half (43%) of the 81
MDD patients diagnosed with personality disorder at baseline. The number of positive personality disorder criteria declined, particularly during the first 6 months,
by a mean of 3 criteria. The decline in reported personality disorder symptoms covaried significantly with declines in the severity of depressive and anxiety symptoms (depressive: P’ ‰=’ ‰.02 for paranoid, P’ ‰=’ ‰.02 for borderline, and P’ ‰=’ ‰.01 for avoidant; anxiety: P’ ‰=’ ‰.08 for paranoid, P’ ‰=’ ‰.01 for borderline, and P’ ‰<‘ ‰.001 for avoidant). Changes in patients’ perceptions of self as measured by neuroticism covaried with changes in paranoid (P’ ‰=’ ‰.01) and borderline (P’ ‰<‘ ‰.001) personality disorder symptoms.

Conclusions: Among MDD patients, the categorical stability of concurrent personality disorder diagnoses assigned while depressed is relatively poor, but the dimensional stability is moderate. The remission of depression as well as variations in Axis I comorbidity, particularly anxiety disorders, influences personality disorder diagnoses. These diagnostic difficulties most likely reflect broader variations in patients’ perceptions of self over time, not merely psychometric problems related to the pertinent diagnostic criteria.

Submitted: August 18, 2008; accepted January 2, 2009.

Online ahead of print: January 12, 2010.

Corresponding author: Erkki T. Isometsä, MD, PhD, Institute of Clinical Medicine, Department of Psychiatry (Välskärinkatu 12 A), PO Box 22, 00014 University of Helsinki, Finland (erkki.isometsa@hus.fi).