In one study, researchers measured omega-3 levels in 132 people, average age 68, who had recovered from major depression.
Those who had higher levels of total omega-3s and EPA (eicosapentaenoic acid)—as well as lower levels of the omega-6 arachidonic acid compared to EPA—had better cognitive scores than those with lower omega-3 levels and higher omega-6 levels.
In participants with recurring depression, those with higher total omega-3 levels scored better on memory tests of immediate recall than those with lower omega-3 levels. Commenting on the findings, doctors said omega-3 may play a direct role in immediate recall memory.