The early manifestations of bipolar disorder: a longitudinal prospective study of the offspring of bipolar parents

Objective:  A major aim of this longitudinal high‐risk study is to identify reliable early indicators of emerging bipolar disorder (BD) among offspring from well‐characterized parents. Methods:  High‐risk offspring were recruited from families in which one parent had BD diagnosed on the basis of the Schedule for Affective Disorders and Schizophrenia – Lifetime version (SADS‐L) interviews and DSM‐IV diagnostic criteria and the other parent was well. Bipolar parents were further subdivided on the basis of response or non‐response to long‐term lithium. A comparison group of offspring was recruited from well parents diagnosed on the basis of either SADS‐L interviews or the family history method. All consenting offspring from high‐risk and control families were assessed longitudinally with the Schedule for Affective Disorders and Schizophrenia for School‐aged Children – Present and Lifetime version (KSADS‐PL) interviews and DSM‐IV diagnoses were made on a blind consensus review. The offspring were reassessed on average annually, as well as at any time symptoms developed. Results:  Antecedent conditions to BD in both high‐risk groups included sleep and anxiety disorders, while attention‐deficit hyperactivity disorder and pre‐psychotic conditions were antecedents among the offspring of lithium non‐responders only. Among those offspring developing BD, the index mood episode was almost always depressive. Conclusions:  Despite a specific genetic risk, BD began with non‐specific psychopathology and/or depressive disorders in a majority of offspring. Therefore, diagnosis based only on cross‐sectional assessment of symptoms appears to be insufficient for the accurate early detection of emerging BD. Other parameters such as family history and associated antecedents should be taken into account.