title: Biological aspects of depression.
abstract: Several neuroendocrine studies with the clonidine-growth hormone stimulation test show endogenous depressive patients to have a reduced GH response as compared to neurotic depressives, schizophrenics and controls. The blunted GH response to clonidine seems to be a trait marker or vulnerability factor for mono- and bipolar endogenous depression. It could be explained by a reduced postsynaptic alpha 2-adrenoceptor sensitivity or of structures related to them. The sensitivity of alpha 2-adrenoceptors is influenced by both, the endorphinergic and cholinergic systems. First results supporting this concept are presented and discussed.
mesh_terms: D003000:Clonidine; D003866:Depressive Disorder / Q000503:physiopathology*; D005260:Female; D013006:Growth Hormone / Q000502:physiology*; D006801:Humans; D011942:Receptors, Adrenergic, alpha / Q000502:physiology*; D011950:Receptors, Cholinergic / Q000502:physiology; D011957:Receptors, Opioid / Q000502:physiology
chemical_list: D011942:Receptors, Adrenergic, alpha; D011950:Receptors, Cholinergic; D011957:Receptors, Opioid; D013006:Growth Hormone; D003000:Clonidine