Spring Fever: Body Chemistry and Seasonal Biology

2010 April 6

by Dr. Gabrielle Francis

“It’s spring fever…. You don’t quite know what it is you DO want, but it just fairly makes your heart ache, you want it so!”
— Mark Twain

Spring fever is the body chemistry aligning with the biology of the changing seasons. It is a warm welcome that follows the Seasonal Affective Disorder of the winter…

It comes with telling signs: restlessness, intense nervous excitement, and high-energy spurts, loss of appetite, insomnia, a yearning to break away or a desire for love. Spring fever has appeared in love poems, stories and medical literature.

Statistically, at least half of the people who live in the northern latitudes of USA and Canada experience more intensely the symptoms of Spring fever. Longer sunny days seem to have a direct impact on people’s psychological and physiological responses to the passage of the seasons. Spring fever is not just in the head. It is caused by an adjustment in body chemistry and seasonal biology.

Spring Fever and Body Chemistry

Doctors have attributed the phenomenon of spring fever to human reaction to seasonal changes. Since the mid 1980s, scientists have validated the diagnosis of Seasonal Affective Disorder (SAD), a depression and mood disorder that emerges during the fall and winter months. They have also perceived a noticeable departure of SAD symptoms with the coming of spring and summer. One reason is the realignment of the body’s chemistry with sunlight. Changes during spring can readjust body chemistry, specifically the internal body clock that responds to sunlight.

The circadian rhythm of the internal body clock is affected by light. The body’s secretion of melatonin, a hormone that influences sleep and energy levels, is also affected by light. During the winter, the body’s secretion of melatonin is relatively high; during spring, however, the level of melatonin decreases, which results in greater wakefulness. Serotonin levels also increase during spring, which accounts for the breakaway sense of elation. Research also suggests that spring weather is linked to spikes in hypomania, when individuals experience a sense of inflated grandiosity, uninhibited pursuit of “the chase,” and a significantly reduced need for sleep.

Spring Fever and Seasonal Biology

Is love in the air during spring? Is there a biological basis for this as well? Studies show that sexual behavior in animals follows a seasonal pattern. Seasonal cycles in human rates of conception occur as well. Historically, there have been more births in spring, which means that babies are conceived most often during the summer months, when the luteinizing hormone (that spurs the production of testosterone in men and triggers ovulation in women) is at its peak.

During spring with the onset of greater sunlight there is an increase in testosterone, estrogen and serotonin. The sperm counts are also thought to increase in the spring.

Cure for Spring Fever = Love