Getting to Know Your 5 Essential Brain Chemicals

by Jerry Kennard, Ph.D. Medical Reviewer

Many of our moods depend on our nervous system. Too much or too little of the chemicals that speed things up or slow things down and the whole thing can go out of kilter. The basis of many of our medications is to correct these imbalances. Here are just a handful of the essential neurotransmitters and the way they work.

Glutamate & GABA

Glutamate and GABA can be thought of as mainstay neurotransmitters. They slog away in high concentrations within the brain where one (glutamate) is the throttle and the other (GABA) acts as the brake. Glutamate has an important role in learning and memory, but too much and it can lead to agitation, impulsive behavior and even violence. GABA has the opposite effect. It increases our levels of tranquility by inhibiting too much nerve activity.


Serotonin is all about serenity and hopefulness in moods. The latest generation of SSRI drugs aim to increase levels of serotonin within the brain. Low levels of serotonin are associated with depression.


Dopamine is our arousal and stimulation neurotransmitter. We associate dopamine with rewards as it controls our appetite for sex, eating, pleasure and even creative thinking. Too little dopamine can lead to depression, but too much can lead to dependence on the agent doing the stimulating.


Endorphins are both hormones and neurotransmitters and they can pack a punch. We have at least 20 different types of endorphins some of which are more powerful than morphine. We tend to release endorphins when we’re under stress or in pain. The higher the level of endorphin, the less pain we feel and the more relaxed, even euphoric, we can become. Foods like chocolate or chilli peppers enhance the secretion of endorphins.

Noradrenaline (norepinephrine)

Noradrenaline is the main neurotransmitter of the sympathetic nervous system. We associate this with our fight-or-flight mechanism and moderation of other physical actions such as heart rate and blood pressure. Too little noradrenaline and we become sleepy and lethargic. Too much and our thoughts run away with us, we become twitchy and nervous, our hands and feet go cold and our blood pressure climbs.

Jerry Kennard, Ph.D.
Meet Our Writer
Jerry Kennard, Ph.D.

Jerry Kennard, Ph.D., is a Chartered Psychologist and Associate Fellow of the British Psychological Society. Jerry’s work background is in mental health and, most recently, higher education. He is the author of various self-help books and is co-founder of