Frontal lobe function and social adjustment in patients with schizophrenia: near-infrared spectroscopy

The study evaluated relationships between frontal lobe function in patients with schizophrenia and both their social adjustment and medication, using 22-channel near-infrared spectroscopy (NIRS).

One hundred ninety-nine stable patients with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision schizophrenia, whose medication had not been changed within the preceding 3 months and who were able to visit our clinics for NIRS, were the study subjects. As a comparator, 144 healthy volunteers who underwent a physical examination and the Mini-International Neuropsychiatric Interview also received NIRS.

The main outcomes evaluated were frontal lobe oxyhemoglobin concentration (OxHb) measured by NIRS, current medication, social adjustment, and scores on the Brief Psychiatric Rating Scale. The OxHb in schizophrenic patients (0.878 ± 1.1801 mM mm; n = 199) was significantly lower than that in the healthy volunteers (2.085 ± 1.7480 mM mm: n = 100) (p < 0.001). NIRS-measured OxHb values reflected disease severity and degree of social adjustment in schizophrenic patients.

Patients with higher OxHb values were socially better adjusted than those with lower OxHb values. Patients treated with atypical antipsychotic monotherapy showed lower treatment resistance and better social adjustment than those treated with combination therapy.