Fig. 1
Participants’ distribution and flow during the trial based on the Consolidated Standards of Reporting Trials. The participants’ distribution and flow during the trial based on the Consolidated Standards of Reporting Trials [52]. It indicates total number of study participants who were recruited (N = 282), excluded from enrolment based on exclusion criteria (N = 66), enrolled for the 8-week study (fish oil arm = 109; soybean oil arm = 107), dropped out before the 8 weeks (fish oil arm = 23; soybean oil = 11) and those who completed the 8-week trial period and were included in the analysis (fish oil = 86; soybean oil = 96).The difference in completion between the two groups was, however, not significant at the end of study (X2(1) = 1.64; p value = 0.20), and did not significantly influence the change in BDI-II depressive symptom scores in fish oil (0.41 (95% CI − 4.49 to 5.32), p = 0.87) and soybean oil (− 3.21 (95% CI − 13.18 to 6.76), p = 0.52) groups