Dopamine is a neurotransmitter that is released in specific pathways in the brain. Dopamine takes part in the regulation of motor control, behaviour and nausea and vomiting. Dysfunctional dopamine regulation is thought to be involved in several neurological disorders including attention-deficit hyperactivity disorder (ADHD), Parkinson’s disease and schizophrenia. Dopamine is also a key chemical involved in drug dependence.