Impaired but undiagnosed.
OBJECTIVE
To investigate the prevalence and outcomes of individuals with psychosocial impairment not meeting DSM-III-R criteria for any of 29 well-defined disorders and to suggest operational definitions for not otherwise specified (NOS) diagnoses and V codes.


METHODS
Two-stage general population sampling resulted in 1,015 youths aged 9, 11, and 13 years being interviewed in the first wave of the Great Smoky Mountains Study. They were reinterviewed 1 year later using the Child and Adolescent Psychiatric Assessment.


RESULTS
The weighted prevalence of sibling relational problems was found to be 1.4%. That of parent-child relational problems was 3.6% and that of relational problems NOS was 0.6%. The overall rate of symptomatic impairment was 9.4%. Across a variety of "caseness measures," those with symptomatic impairment proved to be more disturbed than those without either a diagnosis or impairment, and as disturbed as those with a diagnosis but without impairment.


CONCLUSION
Children and adolescents who do not meet DSM-III-R criteria for any well-defined disorder but who have symptoms associated with psychosocial impairment should be regarded as suffering from a psychiatric disorder. It is suggested that researchers adopt this definition for the many NOS diagnoses included in the DSM nosology and implement it in their research diagnostic algorithms.