The most serious "side effect" of a medication is death. If the patient is a child or adolescent and the medication is being prescribed for a non-life threatening psychiatric condition, such a death is especially tragic. Therefore, even the suspicion of an association between a psychotropic medication and death among children or adolescents may have major ramifications for the use of the drug. If the association is real, restriction of the use of the medication may be warrant-ed. If the association is not real, the coincidental occurrence of sudden death among individuals taking psychotropic medication, then the medication armamentarium may be needlessly restricted and youngsters in need of treatment may not receive an efficacious therapy. The major aim of this study is to examine the relationship between sudden death in children and adolescents and the use of tricyclic antidepressants (TCA's), or of concomitant methylphenidate and clonidine therapy. The project will involve a post-mortem examination of the medical history of a series of children and adolescents, aged 7 through 19 years, whose deaths were sudden and unexplained. Specifically, a post-mortem of 400 sudden, unexplained deaths among children and adolescents in the United States will be conducted in order to determine the proportion using a TCA or clonidine with methylphenidate at the time of their death. A comparison group of youngsters who died in motor vehicle traffic accidents will allow us to determine whether there is a significant association of unexplained sudden death among young people and TCA use or concomitant methylphenidate and clonidine therapy. The information yielded by this study will provide data upon which rational decisions can be reached concerning the safety of tricyclic antidepressants or combined treatment with methylphenidate and clonidine hydrochloride.