Reliability of post-mortem psychiatric diagnosis for neuroscience research.

Objective: The validity of post-mortem human brain research relies upon accurate clinical and psychopathological diagnosis. Current literature indicates few instances where standardized diagnostic assessment tools such as the Diagnostic Instrument for Brain Studies have been utilized. The primary aim of the present study was to investigate the degree of concordance between predominant ante-mortem psychiatric diagnoses indicated in medical records, and post-mortem diagnoses derived through structured diagnostic instruments such as the Diagnostic Instrument for Brain Studies and the Item Group Checklist of the Schedules for Clinical Assessment in Neuropsychiatry.

Methods: Fifty-eight subjects from the New South Wales Tissue Resource Centre, assigned a clinical psychiatric diagnosis after death, were included in the study. The predominant ante-mortem diagnosis of each case was compared to the corresponding post-mortem diagnosis obtained through structured case reviews to which either the Diagnostic Instrument for Brain Studies (from 2001) or the Item Group Checklist of Schedules for Clinical Assessment in Neuropsychiatry (before 2001) were applied.

Results: Comparison of ante-mortem and post-mortem diagnoses produced an overall kappa coefficient of 0.66. Kappa coefficients for the schizophrenia cohort were 0.61, 0.35 for the schizoaffective cohort, 0.95 for the major depressive disorder cohort and 0.70 for the bipolar disorder cohort.

Conclusions: There was moderate-excellent inter-rater reliability for most cohorts in this sample. There was sufficient disagreement, however, particularly for the schizoaffective cohort, to suggest the value of applying a standardized and structured assessment approach to psychiatric diagnosis. A standardized approach would likely enhance both the accuracy of diagnosis and the prospective validity of tissue-based research. The present study also highlights the importance of accurate and detailed medical record keeping at a symptom-based level across all mental health professions. In the absence of clear and adequate symptom-based detail, the reliability of both ante-mortem and post-mortem diagnosis may be compromised.