Of 200 patients receiving levodopa (L-DOPA) therapy the first 20 Patients received 4 to 6.5 gm of LDOPA per day. Seven of 12 Parkinsonian patients who were also depressed showed a remission of depression during L-DOPA treatment, however this change generally correlated with the degree of motor improvement. In two patients the mood elevation was clearly out of proportion to the motor improvement, and one of these developed a "hypomanic-like" state. A third Patient developed agitated behavior after one year of L-DOPA therapy. Six of nine males reported spontaneous penile erections and one resumed successful intercourse after three years of impotency. Of four patients with organic dementia, three showed no detectable improvement but one raised his Wechsler Memory Quotient from 59 to 86.
O'Brien CP, DiGiacomo JN, Fahn S, Schwarz GA. Mental Effects of High-Dosage Levodopa. Arch Gen Psychiatry. 1971;24(1):61-64. doi:10.1001/archpsyc.1971.01750070063008