MULTIDIMENSIONALLY IMPAIRED DISORDER - IS IT A VARIANT OF VERY EARLY-ONSET SCHIZOPHRENIA

Objective: To examine the validity of diagnostic criteria for a subgro up of children with atypical psychosis (n = 19), designated here as '' multidimensionally impaired.'' These children are characterized by poo r attention and impulse control, psychotic symptoms, and poor affectiv e control. Method: Children and adolescents (n = 19) meeting our crite ria for multidimensionally impaired syndrome with onset of psychotic s ymptoms at or before age 12 years were identified from a total of 150 in-person screenings for very early-onset schizophrenia between 1990 a nd 1996. We compared the premorbid adjustment, family history, follow- up status, and laboratory measures for a subgroup of these children wi th those of (1) a rigorously defined group of 29 children with DSM-III -R schizophrenia and (2) 19 children with attention-deficit hyperactiv ity disorder. Results: Patients with multidimensionally impaired syndr ome and patients with very early-onset schizophrenia shared a similar pattern of early transient autistic features, postpsychotic cognitive decline, and an elevated risk of schizophrenic-spectrum disorders amon g their first-degree relatives. This pattern was not seen in the atten tion-deficit hyperactivity disorder group. In contrast to very early-o nset schizophrenia, the multidimensionally impaired group had signific antly poorer scores on the Freedom From Distractibility factor on the WISC-R, a less deviant pattern of autonomic reactivity, and no progres sion to schizophrenia. Conclusions: The findings support the distincti on of the multidimensionally impaired cases as separate from those wit h other psychiatric disorders, and there is somewhat greater evidence to suggest that this disorder belongs in the schizophrenia spectrum.