One of the earlier studies into this effect was conducted by researchers from Toyama Medical and Pharmaceutical University in Japan and published in 1996. In a double-blind study, 41 male and female students were assigned to take daily capsules containing either between 1.5 and 1.8 g of DHA or a placebo consisting of 97 percent soybean oil and 3 percent fish oil. At both the beginning and end of the study, participants were given tests measuring their frustration response, reaction time and any symptoms of dementia.

The study began at the end of students' summer vacation and continued for three months. The study concluded during a stressful time in each student's life, such as final exams.