Neurotransmitters are endogenous signaling molecules that alter the behavior of neurons or effector cells. They stimulate or they calm. They relay signals between nerve cells (neurons). The brain uses neurotransmitters to trigger hormones to tell your heart to beat, your lungs to breathe, and your stomach to digest. This way they are chemical messengers in the brain that also influence a person’s thoughts and feelings. They can affect mood, sleep, concentration, weight, and they can cause adverse symptoms when they are out of balance. The neurotransmitter levels can be depleted in many ways. Stress, poor diet, neurotoxins, genetic predisposition, drugs, including alcohol, nicotine and caffeine usage can cause these levels to be out of optimal range.
The main neurotransmitter are dopamine, serotonin, oxytocin and noradrenalin. When there is an imbalance of serotonin and dopamine, a person can feel depressed or anxious.