You may have heard the word “serotonin” used in connection with mental health. Serotonin is a neurotransmitter (a chemical that carries signals through the brain) that serves many functions, but it is most popularly recognized for contributing to a sense of happiness and wellbeing.
Of the 40 million brain cells, most are influenced by serotonin — including brain cells related to mood, sexual desire, appetite, sleep, memory and learning, according to WebMD. Low serotonin levels have been linked to depression and mood disorders. Some depression medications work by increasing the levels of serotonin in the brain.
The concept of serotonin affecting mood may be relatively common, but here are five not-so-commonly-known facts about this chemical.
- More than 90 percent of serotonin is produced in the gut, not the brain. There is a close tie between the digestive system and psychological health. Altered levels of serotonin in the gut have been linked to diseases such as irritable bowel syndrome. Some studies have also reported connections between gut bacteria and anxiety.
- Your daily cup of coffee may affect serotonin levels. Studies have shown that caffeine can increase the amount of serotonin receptors as well as the sensitivity of serotonin receptors. However, some research has also pointed to the possibility that chronic caffeine use may reduce serotonin levels over time.
- Sunshine can really make you happy. The lack of sunlight contributes to low serotonin levels. This may be a factor in Seasonal Affective Disorder (SAD), in which people experience depression and lower moods during the winter season. A 2002 study found the rate of production of serotonin was directly related to the duration of bright sunlight.
- Serotonin can help you sleep. The famous mood-boosting hormone also plays a role in your sleep schedule. Serotonin is a precursor to melatonin, the hormone that regulates your sleep-wake cycle. Melatonin is made naturally in the body and is stimulated by the dark, while serotonin is stimulated by sunshine.
- Diet makes a huge difference. Certain foods can trigger the production and release of serotonin, contributing to an elevated mood. These foods are typically those high in tryptophan—a precursor to serotonin— and include salmon, poultry, spinach, eggs, soy products and nuts.