This paper represents the third part of a report on the "switch Process" and attempts to integrate the findings relevant to this process and to develop biological theories concerning the onset of manic illness. The following characteristics are important components of an hypothesized dysfunction in the switch process into mania: (1) the defect is genetically transmitted; (2)it must be activated; and (3) it is reversible. We speculate that a genetic abnormality may affect, in part, the mechanism which regulates the amount of functional neurotransmitter, norepinephrine, at the synaptic cleft, perhaps by interference with the transport of norepinephrine across neuronal membranes. It is emphasized that the hypotheses advanced require validation and must be modified as our knowledge of biological interactions in brain increases. A possible relationship of switch processes and changes in neurotransmitters to episodic metabolic illnesses, and to the "high" experienced on various drugs, is suggested.
Bunney WE, Goodwin FK, Murphy DL. The "Switch Process" in Manic-Depressive IllnessIII. Theoretical Implications. Arch Gen Psychiatry. 1972;27(3):312-317. doi:10.1001/archpsyc.1972.01750270022003