This interview study investigated nonspecific psychological distress in the general population. A probability sample of 200 adults was drawn from heterogenous sex, class, and ethnic groups in New York City. Twenty-five scales were developed. Eight reflect a single dimension of nonspecific distress (eg, Poor Self-esteem, Sadness, and Perceived Physical Health) and 17 are distinct from these and from each other (eg, False Beliefs and Perceptions, Manic Characteristics, Insomnia, Antisocial History, and illness-linked Somatic Problems). Both sets of scales have become part of a new interview instrument, the Psychiatric Epidemiology Research Interview (PERI). Questions are raised about the nature of nonspecific distress in relation to Frank's construct of "demoralization," the value of the measured dimensions of psychopathology that contrast with it, and the relation of PERI, which uses a self-report format, to diagnostic interviews developed here and abroad.