What is a neurotransmitter? A neurotransmitter is a chemical messenger.  It transfers information to the brain and other parts of the body. What are symptoms of neurotransmitter imbalance? The following are examples of neurotransmitter imbalances. Anxiety symptoms Symptoms of depression Insomnia Overeating Obesity Fatigue ADD/ADHD Bipolar What is Neurotransmitter testing? Neurotransmitter tests will help determine your profile of brain...