FUNCTIONAL NEAR-INFRARED SPECTROSCOPY: A POTENTIAL TOOL IN ASSISTING DIAGNOSTIC APPLICATIONS FOR PSYCHIATRIC DISORDERS

Abstract Background Psychiatric disorders such as mood disorders are increasingly common in modern society, carrying social and economic burdens, including the risk of suicide. Timely identification of these disorders and intervention is crucial, and ongoing research explores adjunctive diagnostic tools and biomarkers, alongside patient history, to aid early detection. Aims & Objectives The study seeks to utilize functional near-infrared spectroscopy (fNIRS) for its cost-effectiveness and ease of use, aiming to improve the diagnosis and differentiation of Major Depressive Disorder (MDD) and Bipolar Disorder (BP) from the healthy control (HC) group. Method Thirty participants each from MDD, BP, and HC groups, were diagnosed using DSM-IV criteria, Hamilton Depression Rating Scale, and Clinical Global Impression scores, and performed a verbal fluency task. They recited Korean vowels and produced words starting with specific consonants within the allotted times. The fNIRS system, NIRSIT, included 24 lasers, 32 photodetectors, and oxyhemoglobin waveforms were analyzed for integral and centroid values. One-way ANOVA and ANCOVA assessed differences and the impact of age, education, and task performance. Results Figure 1 displays the average oxyhemoglobin waveforms in the frontal region (R1) and bilateral temporal regions (R2) for each group. The MDD participants were older than the BP and HC groups (F = 14.664, p<0.005). Task performance was similar for MDD and HC, and better than BP (F = 5.622, p <0.005). One- way ANOVA indicated significant differences in integral values across the groups and post-hoc analyses highlighted substantial distinctions between the healthy control (HC) and the psychiatric disorder groups (HC vs BP, HC vs MDD; P <0.05). Although no significant differences were observed in centroid values between patient groups, each group exhibited unique patterns. Discussion & Conclusion Using fNIRS, the findings suggest that IV and CV, derived from changes in hemoglobin waveforms, hold promise in distinguishing individuals with mood disorders from healthy controls. While further research is needed to explore their applicability to other psychiatric conditions such as psychosis, there is potential for them to serve as auxiliary diagnostic tools in the future for personalized psychiatric treatment.