The brain is an extremely complex organ that never stops changing and developing. It contains 100 billion neurons bound together by neurotransmitters like serotonin, dopamine, and glutamate—all of which affect critical functions like mood, the capability of feeling pleasure and pain, and inhibition. With billions of chemical reactions taking place at one time, the possibility of a chemical imbalance is feasible. So feasible, in fact, that 1 in 4 people suffer from a mental illness. That’s why understanding brain function is crucial to diagnosing, managing, and treating mental disorders.