User:Psychofarm/Dopamine and BiPolar Disorder

Dopamine
Dopamine pathways in the midbrain help to regulate motor activity, motivation and reward circuits. Behavioral changes of the manic phase such as increase in goal-directed behavior and excitement may involve these dopaminergic pathways. Mesolimbic dopaminergic pathways may be directly involved in the selection and coordination of goal-directed behavior, especially those elicted by reward stimuli. Homovanillic acid (HVA), a metabolite of dopamine, is reduced in the cerebral spinal fluid (CSF) of some depressed patients. Conversely, CSF levels of HVA are increased in some manic patients. Pharmacological agents which act on the dopamine pathways further implicate dopamine in the pathogenesis of bipolar symptoms. The dopamine precursor L-dopa can produce hypomania in bipolar patients. Amphetamine, which promotes dopamine release can cause hypomania in bipolar patients and can induce hypomanic symptoms in normal people. Bromocriptine and piribedil, which are direct dopamine agonists exhibit antidepressant properties and cause mania in some bipolar patients. Conversely, neuroleptics which block dopamine receptors have antimanic properties. Pramipexole, a dopamine agonist at the D2/D3 site, shows antidepressant efficacy as an augmentation strategy in Bipolar patients who are failing treatment with mood stabilizers.