Your thinking ability becomes less sharp when you are depressed, revealed researchers from the University of Michigan's medical school and depression center. They categorized this condition as a mood disorder.
Researchers analyzed 612 women for the study. Over two-thirds of the participants had experienced either major depression or bipolar disorder. The test asked the study subjects to react rapidly when certain letters flashed briefly on a screen amid a random sequence of other letters. It was seen that women with depression or bipolar disorder did equally badly on the test, which required sustained concentration. Compared to the group of women with no mental health conditions, the groups with either diagnosis lagged noticeably on this standard test of cognitive control.
Brain scans of the women showed that the women with depression or bipolar disorder had different levels of activity than healthy women in a particular area of the brain called the right posterior parietal cortex. In women with depression, the activity in this area was higher than in healthy individuals, while in those with bipolar disorder it was lower. The area where the differences were seen helps control executive function, activities such as working memory, problem solving and reasoning.
Kelly Ryan, neuropsychologist and lead author of the study, said, "The results could transform the way doctors and patients think about, diagnose and treat depression."
The study is published in the BRAIN