In one recent study, meditation was reported to increase release of dopamine. The study by Perreau-Linck and colleagues is the first to report that self-induced changes in mood can influence serotonin synthesis. This raises the possibility that the interaction between serotonin synthesis and mood may be 2-way, with serotonin influencing mood and mood influencing serotonin.
Exposure to bright light is a second possible approach to increasing serotonin without drugs. Bright light is, of course, a standard treatment for seasonal depression, but a few studies also suggest that it is an effective treatment for nonseasonal depression and also reduces depressed mood in women with premenstrual dysphoric disorder and in pregnant women suffering from depression.
A third strategy that may raise brain serotonin is exercise. A comprehensive review of the relation between exercise and mood concluded that antidepressant and anxiolytic effects have been clearly demonstrated.
The fourth factor that could play a role in raising brain serotonin is diet. According to some evidence, tryptophan, which increases brain serotonin in humans as in experimental animals, is an effective antidepressant in mild-to-moderate depression. Further, in healthy people with high trait irritability, it increases agreeableness, decreases quarrelsomeness and improves mood.