Figure 3. Forest Plot of Omega-3 Fatty Acids for Depression Stratified by Baseline Depression
Severity
Trials in which participants were at least moderately depressed on average before starting
treatment reported a greater efficacy of omega-3 fatty acids when compared to trials in
which participants were only mildly depressed (test for subgroup differences: χ2 = 11.7, df
= 1 (P < 0.0006), I2 = 91%). For stratification of trials by baseline depression severity we
used traditional cutoffs for the HAM-D-17 (mild: 28) 19.
Trials that measured initial depression severity on scales other than the HAM-D-17 were
converted to this scale based on previously defined algorithms 20. Abbreviation: CI=
confidence interval.