BACKGROUND: The high-risk strategy is one of the most powerful approaches for identifying premorbid risk factors and reducing etiologic and phenotypic heterogeneity characteristic of the major psychiatric disorders. METHODS: This paper reviews the methods of high-risk research and findings from previous high-risk studies of anxiety. The preliminary results of the 6-8 year follow-up of a high-risk study of 192 offspring of probands with anxiety disorders, substance abuse, and unaffected controls are presented. The key study measures include comprehensive diagnostic interviews, symptom ratings, indirect measures of brain functioning (neuropsychologic, neurologic and psychophysiologic function), developmental measures, and family functioning measures. RESULTS: The major findings reveal that there is specificity of familial aggregation of anxiety disorders among parents and children; children at high risk for anxiety have increased startle reflex, autonomic reactivity, and stress reactivity, higher verbal IQ, and deficits in paired associative learning as compared to other children. CONCLUSIONS: The finding that family environment and parenting do not differ between children at risk for anxiety disorders and other children, when taken together with the strong degree of specificity of transmission of anxiety disorders, suggests that there may be temperamental vulnerability factors for anxiety disorders in general that may already manifest in children prior to puberty.