First evidence on a general disease ("d") factor underlying psychopathology and physical illness in adolescents.

The coexistence of mental and physical health illnesses could be accounted for by an underlying general disease factor (termed d-factor), reflecting theoretical underpinnings based on possible genetic and pathophysiological overlapping mechanisms. This study evaluated whether the d-factor underlies mental and physical health illnesses in adolescents. A series of confirmatory factor analyses were conducted using data from 1120 adolescents.