Precision, reliability and accuracy in the dating of symptom onsets in child and adolescent psychopathology.

Dates of onset of psychiatric symptoms are required in determining whether diagnostic criteria are met for a number of disorders and for a variety of research questions. However, little attention has been paid to the precision and reliability of their recall by parents and children. We present data from two studies indicating that when symptoms have lasted longer than around 3 months, the month of onset usually cannot be accurately reported, while with symptoms that have lasted a year or more, the year of onset is usually uncertain. The implications of these findings for diagnosis and research are discussed.