Dharmadhikari Ambrish S, Jaiswal Suyog Vijay, Tandle Avinash L, Sinha Deoraj, Jog Nandini
Department of Psychiatry, H. B. T. Medical College and Dr. R. N. Cooper Mun. Gen. Hospital, Mumbai, Maharashtra, India.
Department of Electronics and Telecommunication, Mukesh Patel School of Technology, Management and Engineering, NMIMS University, Mumbai, Maharashtra, India.
J Neurosci Rural Pract. 2019 Apr-Jun;10(2):250-255. doi: 10.4103/jnrp.jnrp_293_18.
Depression, despite being the most common of mental illness lacks any quantifiable and absolute biomarker. Frontal alpha asymmetry (FAA) is proposed as biomarker of depression both in resting and activated state. Yet, the location of extraction of alpha, clinical utility as well as validity of FAA is uncertain. With aim of obtaining clarity on this confusion we conducted this study.
Electroencephalographic frontal alpha power was calculated in patients of depression ( = 24) and compared with healthy controls ( = 17) for the assessment of FAA. Both groups were studied for resting phase and activation phase changes in FAA. For activation phase, auditory stimuli in the form of Indian classical music were used.
Frontal alpha power was measured across FP1, FP2, F3, F4, F7, and F8. Mean powers were compared in resting (before), activated (during) and postactivated resting stage (after). FAA was statistically significant in F7-F8 pair of electrodes and on F7 electrode when compared between cases and controls.
Quest for biomarker for depression churned out FAA as frontrunner. Despite of vast amount of research on it, practical utility eludes us. We need to revisit our approach from conventional search of the diagnostic biomarker; as FAA might reflect component of depression but not totally disorder. In our opinion, we are not yet ready for it and have a road ahead to travel.
抑郁症虽是最常见的精神疾病，却缺乏任何可量化的绝对生物标志物。前额叶α波不对称性（FAA）被提议作为抑郁症在静息和激活状态下的生物标志物。然而，α波提取的位置、临床效用以及FAA的有效性尚不确定。为了厘清这一困惑，我们开展了本研究。
计算抑郁症患者（n = 24）的脑电图前额叶α波功率，并与健康对照者（n = 17）进行比较，以评估FAA。对两组进行FAA静息期和激活期变化的研究。对于激活期，采用印度古典音乐形式的听觉刺激。
在FP1、FP2、F3、F4、F7和F8处测量前额叶α波功率。比较静息（之前）、激活（期间）和激活后静息阶段（之后）的平均功率。病例组与对照组比较时，F7 - F8电极对以及F7电极处的FAA具有统计学意义。
对抑郁症生物标志物的探索使FAA成为领先者。尽管对此进行了大量研究，但我们仍未掌握其实际效用。我们需要重新审视从传统的诊断生物标志物搜索方法；因为FAA可能反映抑郁症的某个组成部分，但并非完全反映该疾病。我们认为，我们尚未为此做好准备，仍有很长的路要走。
