Effects of allergy season on mood and cognitive function.

The study was conducted to evaluate the effects of having allergic reactions (ie, being in allergy seasons without taking medications) on: (1) speed of cognitive processing, (2) psychomotor speed, (3) ability to sustain attention, (4) verbal learning and memory, and (5) mood. Subjects (ten atopic, eight control) were given a neuropsychologic test and mood rating battery in an A-B-A design ie, in, out of, and in allergy seasons. Only atopic subjects exhibited declines in verbal learning, slower decision-making and psychomotor speed on both simple and choice reaction time tests, and lower positive affect during their allergy seasons in comparison to out of allergy seasons. Atopic subjects did not demonstrate declines in ability to sustain attention. Biochemical mechanisms may cause these changes.