FIGURE 5.

Analysis of various parameters of saliva melatonin secretion in two consecutive days from recruited subjects. (a) Period of the melatonin rhythm, calculated by the fitted cosine curve in Figure 4. The period of the depression group was slightly longer, but not significant. (b) The acrophases of saliva melatonin in healthy controls, depressive BD patients, and recovery BD patients. It was significantly phase‐advanced in the depression group. (c) The peak values of saliva melatonin in the fitted curves for each group. (d) The mesor values of saliva melatonin in the fitted curves for each group. (e) Average melatonin levels for the two consecutive days. (f) The maximum value of melatonin for each group at the clock time 05:00 on the second day. (g) The difference between the maximum level and lowest level of melatonin for each group. (h) Two‐day differences of melatonin for each group, calculated by the average absolute values of the difference between two matching time points in the first and second days. (i) Slope of the first daytime is defined as the slope by fitting linearly to the melatonin level at time points 08:00, 11:00, and 14:00. (j) Slope of the second daytime, calculated using the melatonin values on the second day. (k) Slope of the first night is defined as the slope by fitting linearly to the melatonin level at time points 22:00, 01:00, and 05:00. (l) Slope of the second night, calculated using the melatonin values on the second day. ns, non‐significant; *, p value < .05