Neurotransmitter functions in depression.

1. Subgroups of depressions may be identified and treated based on MHPG execution. 2. HVA correlates more with activity than with mood. 3. CSF-5HIAA may be helpful in categorising some depressions. 4. Acetylcholine has some effect on mood most probably through indirect action on other neurotransmitters. 5. GABA is still not adequately investigated. 6. Desensitization of presynaptic adrenergic autoreceptors may explain some of the mechanisms of antidepressant action of drugs. 7. Decreased post-synaptic adrenergic activity is a common effect of most antidepressants and of ECT.