The classification of neurotic disorders still remains an unresolved problem. It has even been argued that there is no necessity to classify such unspecific reaction modes. Nevertheless, modern clinical research and new treatments both suggest and require that distinctions be made in the realm of neurotic disorders. DSM-III has paved the way for classifications based on symptoms, a trend present in DSM-IV and ICD-10 (Table I) drafts. However, the history of those disorders becomes blurred with this approach, and certain questions arise; for instance, what the relationship is between childhood separation anxiety and panic attacks in the adult, or between the latter and agoraphobia, or between childhood separation anxiety and major depression. Some longitudinal data, including that included in the present paper (Tables II—V), suggest a close relationship between these disorders, which is very much in contrast with what occurs in generalized anxiety disorders. Both patients with panic disorder and those suffering from general anxiety disorder tend to become chronic somatizers with advancing age, as is shown in the data presented in this paper.