[Diagnostic errors and temporal stability in bipolar disorder]

The diagnosis of bipolar disorder is frequently modified during the course of the illness.

Diagnostic changes and associated errors are described for 1,153 patients diagnosed as bipolar disorder, aged over 18 years and with at least ten follow-up visits. Data was extracted from a clinical registry of out-patient care specialized in Psychiatry and psychiatric hospitalizations of 25,152 patients representative of an urban area of 240,000 inhabitants. Limit for diagnostic stability was established as the maintenance of the bipolar disorder diagnosis in at least 75% of the visits.

A total of 158 (46.1 %) out of 342 patients diagnosed as having a bipolar disorders in the first visit kept this diagnostic constant in subsequent evaluations. Infradiagnostic initial error was committed with 108 stable patients who were not diagnosed in the first visit. 184 patients diagnosed in the first visit with bipolar disorder had less than 75 % concordant diagnosis along the follow-up and could be considered as initial overdiagnosis. Two hundred and nine out of the 443 patients who were diagnosed as bipolar disorder in their last visit did not keep stability criteria in their follow-up and could be considered therefore as final overdiagnosis. Thirty two stable patients not diagnosed in their last visit could be considered as infradiagnosis final error. Diagnosis from schizophrenia spectrum (F2) appears in one of every four psychiatric visits of the patients included in this study. Overlap was seen in three other categories: anxiety disorders (F4), personality disorders (F6) and substance abuse disorders.

Initial course of bipolar disorder causes difficulties in the diagnosis.