Chang Hsin-An, Chang Chuan-Chia, Kuo Terry B J, Huang San-Yuan
Department of Psychiatry, Tri-Service General Hospital, National Defense Medical Center , Taipei , Taiwan.
World J Biol Psychiatry. 2015;16(5):351-60. doi: 10.3109/15622975.2015.1017606. Epub 2015 Mar 24.
Bipolar II (BPII) depression is commonly misdiagnosed as unipolar depression (UD); however, an objective and reliable tool to differentiate between these disorders is lacking. Whether cardiac autonomic function can be used as a biomarker to distinguish BPII from UD is unknown.
We recruited 116 and 591 physically healthy patients with BPII depression and UD, respectively, and 421 healthy volunteers aged 20-65 years. Interviewer and self-reported measures of depression/anxiety severity were obtained. Cardiac autonomic function was evaluated by heart rate variability (HRV) and frequency-domain indices of HRV.
Patients with BPII depression exhibited significantly lower mean R-R intervals, variance (total HRV), low frequency (LF)-HRV, and high frequency (HF)-HRV but higher LF/HF ratio compared to those with UD. The significant differences remained after adjusting for age. Compared to the controls, the patients with BPII depression showed cardiac sympathetic excitation with reciprocal vagal impairment, whereas the UD patients showed only vagal impairment. Depression severity independently contributed to decreased HRV and vagal tone in both the patients with BPII depression and UD, but increased sympathetic tone only in those with BPII depression.
HRV may aid in the differential diagnosis of BPII depression and UD as an adjunct to diagnostic interviews.
双相II型（BPII）抑郁症常被误诊为单相抑郁症（UD）；然而，目前缺乏一种客观可靠的工具来区分这两种疾病。心脏自主神经功能是否可作为区分BPII和UD的生物标志物尚不清楚。
我们分别招募了116例身体健康的BPII抑郁症患者和591例UD患者，以及421名年龄在20 - 65岁的健康志愿者。通过访谈者和自我报告的方式获取抑郁/焦虑严重程度的测量数据。通过心率变异性（HRV）和HRV的频域指标评估心脏自主神经功能。
与UD患者相比，BPII抑郁症患者的平均R - R间期、方差（总HRV）、低频（LF） - HRV和高频（HF） - HRV显著降低，但LF/HF比值更高。在调整年龄后，这些显著差异仍然存在。与对照组相比，BPII抑郁症患者表现出心脏交感神经兴奋并伴有迷走神经功能受损，而UD患者仅表现出迷走神经功能受损。抑郁严重程度在BPII抑郁症患者和UD患者中均独立导致HRV降低和迷走神经张力降低，但仅在BPII抑郁症患者中导致交感神经张力增加。
HRV作为诊断访谈的辅助手段，可能有助于BPII抑郁症和UD的鉴别诊断。
