Schizophrenia: data point to early roots.

Three new studies lend support to the theory that many cases of schizophrenia stem from derailments of brain development that begin early in life, perhaps in the womb.

The findings, published in the December American Journal of Psychiatry, add to recent efforts to illuminate schizophrenia's developmental origins (SN: 5/29/93, p.346). Still, researchers remain puzzled as to the precise alterations that bring about the disorder's debilitating symptoms, such as apathy, social withdrawal, incoherent trains of thought, and hallucinations.

Schizophrenia typically appears during young adulthood.

"Unique findings coming now and in the future on never-medicated and first-episode patients [with schizophrenia] are likely to provide a fresh and clarified picture of . . . this complex disease," writes Patricia S. Goldman-Rakic, a neuroscientist at Yale University School of Medicine, in a comment accompanying the reports.

Exposure to viral infections during certain months of fetal development may promote some cases of schizophrenia. Previous studies have uncovered an increased rate of schizophrenia in the offspring of women whose second trimester of pregnancy coincided with an influenza epidemic.

Robin M. Murray of the Institute of Psychiatry in London and his colleagues now report that the mothers of 121 persons hospitalized for schizophrenia recall having had more viral infections in the second trimester of those pregnancies than in the first and third trimesters combined.

Influenza accounted for 14 of the 20 second-trimester infections. Six women cited infections at other times during the pregnancy; two of these infections were influenza.

On average, patients who had been exposed to prenatal infections weighed less at birth and experienced more medical complications at delivery than those who had not had such infections.

A second project documents brain changes typical of chronic schizophrenia in 12 men and 12 women between the ages of 19 and 28 who experienced schizophrenia for the first time. The findings indicate that disturbances of brain development occurring in adolescence or earlier may underlie the disease, propose Peg Nopoulos of the University of Iowa Hospitals and Clinics in Iowa City and her coworkers.

The researchers compared brain scans of young adults with schizophrenia who had not taken antipsychotic drugs with those of healthy people of the same age. Patients had markedly less frontal lobe tissue and more cerebrospinal fluid in their brains.

The third study, directed by Anjan Chatterjee of Hillside Hospital in Glen Oaks, N.Y., notes muscular rigidity and related movement disturbances in 15 of 89 first-episode schizophrenics, all young adults who had not received antipsychotic drugs. Patients who had difficulty moving displayed the most severe symptoms of schizophrenia.

For some schizophrenic patients, decreased transmission of dopamine-a chemical messenger in a region of the brain linked to muscle control-may occur early in life, speculates Goldman-Rakic.