RESUMO
To explore the characteristics of exploratory eye movement (EEM) and hypothalamic-pituitary-adrenal axis (HPA) in elderly patients with acute bipolar and unipolar depression. Methods Thirty-eight elderly patients with bipolar depression (bipolar group) and thirty-nine patients with unipolar depression (unipolar group) were enrolled. The 24-item Hamilton depression rating scale (HAMD-24) was used to evaluate depressive symptoms. The levels of peripheral serum adrenocorticotropic hormone (ACTH) and cortisol (COR) were detected. EEM was recorded to obtain the number of eye fixation (NEF), responsive search score (RSS) and discriminant analysis (D). Results Compared with the unipolar group, the bipolar group had earlier onset, longer duration, and more admissions (P＜0.05). In comparison with the bipolar group, the unipolar group had higher levels of ACTH and COR (P＜0.05), and higher abnormal proportion of COR and ACTH levels. D-values were higher and RSS-values were lower in unipolar group than in bipolar group. There were no significant differences in NEF and HAMD total scores and its subfactors between the two groups (P＞0.05). Correlation analysis showed that the D value of unipolar group was positively correlated with COR level (r=0.482, P=0.002) but not with other indexes (P＞0.05). There were no significant correlations between EEM parameters and serum levels of HPA hormones in bipolar group (P＞0.05). Conclusion There are different clinical features, EEM indicators, the serum levels of ACTH and COR between acute unipolar and bipolar depression, which suggests the heterogeneity between the two diseases.