Serotonin is a neurotransmitter that plays a vital role in regulating mood, emotional stability, sleep, appetite, and digestion. Often associated with feelings of calm, contentment, and emotional resilience, serotonin helps the brain and body maintain a sense of equilibrium. Interestingly, around 90% of the body's serotonin is produced in the gut rather than the brain, highlighting the deep connection between digestive health and emotional wellbeing — sometimes referred to as the gut-brain axis.
Low serotonin levels are closely associated with depression, anxiety, obsessive-compulsive patterns, and sleep difficulties. Many common antidepressants (SSRIs) work by increasing serotonin availability in the brain. However, serotonin is not simply a "happiness hormone" — it is a complex regulator of many bodily systems, and its effects depend on where and how it acts. In therapy, understanding serotonin's role can open helpful conversations about lifestyle, sleep, nutrition, and the interplay between physical and mental health, complementing psychological approaches to mood and emotional regulation.
Young, S. N. (2007). How to increase serotonin in the human brain without drugs. Journal of Psychiatry and Neuroscience, 32(6), 394–399.
