Depression can be triggered by traumatic life events, poor diet, genetic conditions, blood sugar imbalances, medical illness, hormone imbalance, lack of exercise, medications, drug and alcohol use, and digestive difficulties. These triggers are known to cause or contribute to neurotransmitter imbalances.
Neurotransmitters are chemical messengers in the brain. The nerve cells of the brain use neurotransmitters to communicate with each other. The messages they send are believed to play a role in mood regulation.
Neurotransmitters in the brain — specifically serotonin, dopamine, or norepinephrine — affect feelings of happiness and pleasure and may be out of balance in people with depression. Dopamine creates positive feelings associated with reward or reinforcement that motivate us to continue with a task or activity. Norepinephrine helps human bodies to recognize and respond to stressful situations. Researchers suggest that people who are vulnerable to depression may have a norepinephrinergic system that doesn't handle the effects of stress very efficiently.
Another neurotransmitter is serotonin or the "feel good" chemical. In addition to helping regulate human mood, serotonin has a number of different jobs throughout the body from your gut to blood clotting to sexual function. Serotonin is produced by serotonergic neurons. Current research suggests that a decrease in the production of serotonin by these neurons can cause depression in some people, and more specifically, a mood state that can cause some people to feel suicidal.
The main symptoms of depression are due to a functional deficiency of the brain monoaminergic transmitters norepinephrine (NE), 5-HT, and/or dopamine (DA), whereas mania is caused by functional excess of monoamines at critical synapses in the brain.
Biochemical reaction in depression
