Major depression is thought to be caused by changes in:
The limbic system is the emotional center of the brain. The monoamines, norepinephrine, serotonin, acetylcholine and dopamine have been implicated in depression. Histamine is not convincingly linked to any psychiatric illness. GABA (gamma-aminobutyric acid) is an inhibitory amino acid neurotransmitter mainly linked to schizophrenia and anxiety. The basal ganglia and cerebellum are involved in motor control. Ref: Waxman S.G. (2010). Chapter 19. The Limbic System. In S.G. Waxman (Ed),Clinical Neuroanatomy, 26e.
Histamine synapses in the Basal Ganglia
Monoamine synapses in the Basal Ganglia
GABA synapses in the Cerebellum
Monoamine synapses in the Limbic System