This is a Research Scientist Development Award (level II) renewal application to continue and expand investigations focusing on children with physical disabilities (and other early biologic insults, such as those associated with prematurity) and their families. In the center of this research is a longitudinal study of 330 families of children with cystic fibrosis, myelodysplasia, cerebral palsy and multiple physical handicaps and a geographically based probability sample of 360 families, interviewed first in 1978-1979 and reinterviewed in 1983-1984. During the next five years, research efforts will be devoted to: (1) further analysis of the longitudinal data of the combined sample to answer key questions concerning the effects of childhood disability on the affected children, their non-disabled siblings and their mothers. Analysis to-date has focused on the epidemiologic goal of establishing the relative risk for disorder (or distress) in the affected children, their siblings and mothers. The next phase of the analysis, proposed here, is directed at identifying factors that enhance or, conversely, diminish the probability of disorder or distress and test multivariate models to specify causal paths leading to psychopathology in individuals. (2) a continuation study (third wave of interviews) to follow-up the families as the children progress into adulthood. Of particular interest in this phase is the investigation of the adult consequences of early problems in both the physically affected children and their normal siblings. (3) a continuation of an ongoing large scale, comprehensive follow-up study of 8-year old children born at very-low-birth weight (1.5 kgm.). The study is now in its second year of fieldwork and includes a cohort of 230 VLBW children and 350 randomly selected age matched controls. Effects of early history of brain growth on later physical growth, neuro-cognitive and psychosocial functioning will be investigated, as well as the relationship among behavior problems, neurologic findings and learning disabilities. (4) identifying a new population of physically disabled children and their families for an investigation of specific mechanisms in the genesis of psychiatric disorder in children at risk because of physical disease.