Is it true that a supplement with a EPA:DHA ratio of 7:1 is improtant for any potential effects on mood?

A number of studies in the psychiatric field have used concentrates of omega-3 with varying higher ratios of EPA:DHA which has led to the impression that EPA may be superior to DHA in this regard. It is difficult to say whether this is valid or not since essentially all of these studies have failed to do direct comparisons with equal doses of omega-3 where higher ratios of DHA:EPA were also employed. Further, higher fish consumptions have been associated with an apparent improvement in mental health in population studies. Such findings are of interest since most of the fish consumed in these studies had greater amounts of DHA than EPA.