Two studies explore the late outcome of minimal brain dysfunction in 73 patients in relation to their initial presentation and predictive factors. Both studies followed the patients for a period of 10 to 20 years. Findings from the first study of initial presentation in relation to adult outcome showed that there was a strong positive correlation between the childhood symptom of social problems and adult inadequate personality, between childhood anti-social behavior and adult personality disorder of the anti-social, passive-aggressive, and impulsive types. Negative correlations were found between childhood hyperactivity and school problem, and a normal psychiatric outcome. In study 2, by a variety of objective and subjective measurements, 20% were judged to have a satisfactory and 80% an unsatisfactory outcome. Findings showed that initail presentation was significantly correlated with a poor outcome in the following respects: multiplicity of behavioral symptoms, multiplicity of neuro-psychological soft signs, low average or borderline intelligence, learning disabilities (especially math and spelling), and special class placement. Initial diagnosis of clearcut organic brain syndrome also carried a poor prognosis, as did schizoid traits in childhood. Treatment, including psychotherapy, medication, remedial tutoring, and special schooling, did not have a differential effect on outcome. (Author/PHR)