Data were obtained from a longitudinal study of children in families in two New York counties. Families were originally sampled in 1975, and the study sample contained children who were between 5 and 10 years of age at original interview and between 13 and 18 years of age at followup. Nearly 80 percent of the families were interviewed at followup. Study findings revealed that internalizing was more prevalent in girls than in boys, whereas externalizing was more prevalent among boys. Substance abuse was approximately equally prevalent in the two sexes. Residential stability was a risk factor for future drug abuse, while residential instability constituted a risk for externalizing. Family variables tended to discriminate externalizing symptoms from substance abuse, with parental mental illness, sociopathy, and remarriage the most specific risks. The only family variable that was a significantly lower risk for internalizing than externalizing symptoms was parental sociopathy. Parent-child relationships showed a complex pattern of specificity, with power-assertive punishment a specific risk for externalizing behavior, inconsistency of rule enforcement a special risk for internalizing symptoms, and maternal inattention a risk factor for substance abuse but a protective factor against internalizing symptoms. 28 references and 5 tables.