Font size: 
Scientists have found a strong association between depression and low levels of a neurotransmitter called serotonin, a chemical substance in the brain that transmits signals. The past few decades have seen a lot of research aimed at the manufacture of anti-depressant drugs that increase serotonin in the brain.
But it is not always practical to use drugs in cases of mild depression or to prevent it in a susceptible individual. Hence, scientists are also exploring methods of increasing levels of serotonin in the brain without using medicines.
According to a study published in the Journal of Psychiatry and Neuroscience in June this year by Elisabeth Perreau-Linck and her colleagues from the Department of Psychology at the University of Montréal in Canada, there is a positive correlation of serotonin levels with good and happy moods and levels fall with the onset of negative emotions. The study was performed on a group of professional actors who consciously worked up good, bad and neutral moods.
This study is the first one to report that self-induced changes in emotions alter serotonin levels. This suggests that perhaps there is a two-way interaction between serotonin and emotions, with emotions influencing serotonin and serotonin influencing mood.
It has been observed that people who are happy and feel good about themselves stay mentally and physically healthy, and for longer periods, as against people who think negative thoughts all the time. Such people have high susceptibility to physical ailments like heart diseases. They isolate themselves from society and feel more depressed because of poor social support and show poor recovery from existing medical conditions.
This was observed in the older population by Dr. A Weiss and colleagues at the Laboratory of Personality and Cognition of the National Institute on Aging, part of the U.S. National Institutes of Health in Baltimore, Maryland. The team studied and analyzed 597 aged participants. They found that negative emotions drive an individual into a vicious cycle of physical and mental disability which is followed by more mental disorder.
Assuming the two-way relationship between serotonin and mood, it is worthwhile considering methods to deliberately induce good moods and cheerful thoughts, as they can enhance people's quality of life.
Exposure to enough sunlight is one approach toward increasing serotonin levels in the brain. A study published in September by Dr. Matthäus Willeit and colleagues from the Department of Biological Psychiatry at the Vienna General Hospital in Austria suggests that serotonin levels go down in winter and are restored in summer.
They studied people who tend to get depressed during winter and found that there was excessive activity of a protein that transports serotonin, leading to early and rapid depletion of the neurotransmitter. The activity was normalized after treatment with artificial light, while in untreated individuals the activity was restored with the onset of summer and adequate sunlight.
Lamps providing high light intensities are now designed to create bright indoor environments, especially in the Scandinavian countries, to combat bouts of depression in winter.
Adequate light, natural or artificial, improves our mood by increasing serotonin levels. Therefore spending enough time outdoors, in ample sunlight, is essential for all people to stay in a healthy and happy state of mind.
The rewards of staying outdoors may be doubled by using that time to exercise, as numerous studies have demonstrated that exercise reduces depression and anxiety, improves stress tolerance, improves cardiovascular health and protects against the risk of dementia.
The health behavior of most people in the world today, comprising unhealthy eating habits, lack of exercise and stress, is considered by health experts to be a risk factor not only for heart diseases but also for mental disorders, especially depression. Several studies conducted in rats suggest the positive correlation of serotonin with exercise.
Dr. F Legrand and team from the University of Reims in France studied 23 individuals suffering from depression and noted that after eight weeks, high frequency exercise training helped to alleviate depressive symptoms in patients.
Dr. M. B. Conroy from the Department of Epidemiology at the University of Pittsburgh in the United States analyzed 497 post-menopausal women and noted that the women who discontinued normal leisurely physical activities after menopause showed greater levels of anxiety and depressive symptoms in addition to low self-confidence and weight gain, as against those women who continued being active.
The WHO recently estimated that depression will soon be the second-leading cause of disability worldwide. Health providers and support groups should make active efforts to diagnose early or prevent this disabling mental condition.
People should be educated and encouraged to modify their lifestyles in order to increase serotonin levels in their brains that will give them a feeling of well-being and happiness. A non-depressed and healthy population is a more productive population and makes society a more amiable place to exist for everyone.
