Most young patients with developmental disorders who consult psychiatrists for the first time during their adolescence may not have mental weakness, but there is high possibility that they may be suffering from comorbidities. We investigated the presence and transition of past psychosomatic symptoms of 73 patients (47 male and 26 female) with developmental disorders. Past information was available in 42 cases, and 59.5% of them had psychosomatic symptoms in their childhood. The symptoms changed for depressive symptoms in many cases. Many cases treated in the past showed good adaptation during their adolescence. Finding psychosomatic symptoms during childhood and intervening at an early time may prevent secondary psychiatric symptoms in their adolescence.