By Marc Sorenson, EdD
We are meant to be in the sunlight for both mental and physical health, and one of the most important phases for sunlight exposure is early life. We have previously discussed such diseases as autism, low bone strength and type-one diabetes as being related to lack of sunlight either in the formative years or even in the womb.
One of the latest pieces of research involves the onset of bipolar disorder (BD), a mental condition characterized by alternating mania and depression, usually interspersed with normal mood. The disorder was previously called manic-depressive illness.
In an 11-nation study, the U.S. was found to have the highest rate of BD and India lowest rate. Or perhaps we should use the word “risk” rather than “rate.” Is it possible that greater sunlight exposure plays a part in India’s lower risk? Research has yet to determine that answer, but a recent study may “shed some light” on the subject. In the Journal of Psychiatric Research, a team of about 50 scientists studied the influence of light exposure during early life on the age of onset of BD. The study covered 23 different countries at different latitudes and assessed light exposure in the early lives of 3896 BD patients. It was found that more sunlight exposure in the first three months of life was associated with a later onset of the disease. The researchers felt that sunlight during this time helped set the circadian rhythms later in life. The researchers concluded with this statement: “This study indirectly supports the concept that early life exposure to light may affect the long term adaptability to respond to a circadian challenge later in life.”
It would be interesting to know if the overall risk of BD is lower in countries or areas where people receive the most sunlight in infancy, of for that matter, during a lifetime. This research, however, shows us that our children, even our little ones, should receive regular, non-burning sunlight exposure.
 Amanda Gardner. U.S. has highest bipolar rate in 11-nation study. Heath.com. March 7, 2011. http://www.cnn.com/2011/HEALTH/03/07/US.highest.bipolar.rates/ Accessed July 21, 2015.
 Bauer M, Glenn T, Alda M, Andreassen OA, Angelopoulos E, Ardau R, Baethge C, Bauer R8, et al. Influence of light exposure during early life on the age of onset of bipolar disorder. J Psychiatr Res. 2015 May;64:1-8