Evaluation of the validity of personality disorder (PD) diagnostic constructs is important for the impending revision of
the Diagnostic and Statistical Manual of Mental Disorders. Prior factor analytic studies have tested these
constructs in cross-sectional studies, and models have been replicated longitudinally, but no study has tested a constrained
longitudinal model. The authors examined 4 PDs in the Collaborative Longitudinal Personality Disorders study (schizotypal,
borderline, avoidant, and obsessive-compulsive) over 7 time points (baseline, 6 months, 1 year, 2 years, 4 years, 6 years, and 10
years). Data for 2-, 4-, 6- and 10-year assessments were obtained in semistructured interviews by raters blind to prior PD
diagnoses at each assessment. The latent structure of the 4 constructs was differentiated during the initial time points but
became less differentiated over time as the mean levels of the constructs dropped and stability increased. Obsessive-compulsive PD
became more correlated with schizotypal and borderline PD than with avoidant PD. The higher correlation among the constructs in
later years may reflect greater shared base of pathology for chronic personality disorders.