The Differences of 2nd to 4th Digit Length Ratio between Schizophrenia Patients and Normal Controls / 신경정신의학

ABSTRACT

OBJECTIVES: The length ratio of the second to the fourth finger (2D 4D) is a known indirect measure of prenatal sex hormone exposure. Sex hormones influence brain development through structural and epigenetic modifications of neurons. We examined the 2D 4D in schizophrenia patients and normal controls to investigate the relationship between prenatal sex hormone exposure and the genesis of schizophrenia. METHODS: The participants were 187 schizophrenia patients (94 male, 93 female) and 190 normal controls (95 male, 95 female). We determined handedness via the Edinburgh Handedness Inventory and age of onset of schizophrenia via clinical records or directly questioning the patients. We measure digit length using vernier caliper and performed T-tests, ANOVA, and ANCOVA to analyze the data. RESULTS: There were no significant 2D 4D differences between schizophrenic participants and normal controls. Also, there was no significant correlation between the 2D 4D and the age of onset of schizophrenia. Among the controls, the 2D 4D was significantly higher (more "feminized") in females than in males (F=4.937, p=.027). But, there were no significant 2D 4D sex differences among the schizophrenia patients (F=3.429, p=.066). CONCLUSION: These results imply that sex hormone changes during fetal development might play some role in the development of schizophrenia.