Diagnosis in adolescent inpatients: diagnostic confidence and comparison of diagnoses using ICD-9 and DSM-III

In a prospective Multi-Centre research study involving four British Adolescent Psychiatry Inpatient Units, all 276 adolescent admissions were diagnosed using both ICD-9 and DSM-III. Ratings of diagnostic confidence for each diagnostic group varied considerably. Clinicians recorded high levels of confidence in the diagnosis of both Schizophrenia and Anorexia nervosa, while considerably lower scores were noted for Adjustment Disorders (ICD-9 3-digit code 309.), and for Emotional Disorders (ICD-9 3-digit code 313.). Exact concordance in diagnoses made for each case using both ICD-9 and DSM-III occurred in 72% of the entire cohort. The dissimilar concordance rates comparing ICD-9 and DSM-III diagnoses for the same patient admissions suggest differences in validity measures, such as face validity and content validity, in the reliability of diagnostic criteria between similarly named disorders across the two systems, and in the clinician's training and attitude to diagnosis. With the recent introduction of DSM-IV following upon ICD-10, further comparative studies are needed to examine both reliability and validity issues into diagnosis and classification in child and adolescent psychiatry.