Hippocampus Changes May Be Factor in Positive Symptoms of Schizophrenia

New research reported in the March Brain suggests the possibility that a deformed hippocampus drives the psychotic symptoms of hallucinations and delusions. Researchers found that a shrunken left hippocampus, as well as a deformity in the CA1 subfield of the left hippocampus, was linked with positive symptoms such as hallucinations and delusions, but not with negative symptoms, in a sample of 32 schizophrenia subjects. The same changes were not found in a group of 34 healthy control subjects. Moreover, the smaller the left hippocampus and the more deformed its CA1 subfield, the more prominent were the schizophrenia subjects' delusions and hallucinations and the higher were the doses of antipsychotic medications that the subjects needed to quell their these symptoms.

The finding has clinical implications, the lead scientist, Kolja Schiltz, M.D., an adjunct associate professor at Otto von Guericke University in Magdeburg, Germany, told Psychiatric News. The left hippocampus, and particularly its CA1 subfield, could be monitored longitudinally in a patient, he explained. If the hippocampus and CA1 subfield became more deformed, it might indicate that the patient needs more efficacious antipsychotic treatment.

Psychiatric News has reported on research into other factors associated with schizophrenia in addition to hippocampus size, such as genes or the parasite Toxoplasma gondii. Read that coverage here and here. For another study on genetic links to schizophrenia, see the American Journal of Psychiatry.

 

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