Meteorology and mood in bipolar disorder

An Australian study looking at seasonal variation of manic and depressive symptoms in bipolar disorder has added to the body of knowledge on this topic. The researchers measured specific meteorological factors such as atmospheric pressure, hours of sunshine, relative humidity, and daily maximum and minimum temperatures compared to self-reported daily mood change in people diagnosed with bipolar disorder. 

Highs and lows, ups and downs: meteorology and mood in bipolar disorder by Ben Bullock, Greg Murray and Denny Meyer was published in PLoS ONE recently, and the results indicated that the daily maximum temperature was the only meteorological variable to predict clinically-relevant mood change. Sunshine hours, humidity and minimum temperatures had no noticeable effect. This contradicts some other studies on these effects, but it was quite a small study.