serotonin

Serotonin or 5-hydroxytryptamine (5-HT) is one of the dominant neurotransmitters (chemical transmitters of nerve impulses) in our body. Although serotonin is mainly manufactured in the brain, most of our serotonin supply is found in the digestive system and in blood platelets.

Apart from its nervous system effects, serotonin also influences the functioning of the heart, blood vessels, muscles, hormones, digestion, milk production and immune responses. In the brain it manages mood, hormonal fine tuning, sexual desire, appetite, sleep and motivation. As it mediates between emotional response and judgment, a lack of serotonin is associated with repetitive behaviour, obsessive compulsive activities, impulsive aggressive behaviour and eventually apathy and a sense of worthlessness. Women tend to become more cautious when they have too little serotonin while men become more impulsive. Serotonin is produced from the amino-acid tryptophan inside brain cells. High carbohydrate meals, exercise and bright light improve serotonin levels. Medication which changes serotonin activity in the brain is used to treat depression. There are two main types, the SSRIs (selective serotonin reuptake inhibitors) and the SNRIs (serotonin and norepinephrine reuptake inhibitors).