The Sex-Related Differences of Relationships between 2D : 4D Ratio and Electroencephalographic Coherence in Patients with Schizophrenia Compared with Controls

ABSTRACT

OBJECTIVES: Prenatal testosterone is known to influence both cerebral laterality and 2nd to 4th digit ratio (2D 4D). Epigenetic changes are thought to play some role in it. We studied sex-related differences between 2D 4D and cerebral laterality in patients with schizophrenia and controls to examine the effects of prenatal testosterone in the development of schizophrenia. METHODS: Forty one men (18 schizophrenic patients and 23 controls) and 40 women (17 schizophrenic patients and 23 controls) were recruited from one psychiatric hospital in Korea. The 2D 4D and electroencephalographic (EEG) coherence in 19 channels (66 pairs of interhemispheric coherence and 54 pairs of intrahemispheric coherence) were measured. The sex-related statistical analyses between 2D 4D and EEG coherence in controls and patients with schizophrenia were performed using multiple regression. RESULTS: In male patients, the relationship between 2D 4D and right intrahemispheric EEG coherence showed mainly positive correlation in delta and theta frequency bands, while it showed negative correlation in male controls. In female patients, the relationship between 2D 4D and interhemispheric EEG coherence showed stronger positive correlation in alpha and beta frequency bands, while it showed weaker positive correlation in female controls. CONCLUSIONS: Low prenatal testosterone may play certain roles in altered correlation between 2D 4D and cerebral laterality in schizophrenia and the development of schizophrenia by epigenetic mechanism.