Improvement of motor and psychological symptoms by L-DOPS (L-threo-3,4-dihydroxyphenylserine) in totally 20 cases with Parkinson's disease (PD), including 5 cases of juvenile or early onset parkinsonism (JP) and one case of pure akinesia was analysed. Improvement was obtained in about two thirds of the cases on symptoms of freezing in gait, difficulty of postural control, depressive mood and bradyphrenia. Severity of freezing in gait and that of the depressive mood were graded in five stage (from 0 to 4) scale and the improvement was evaluated by A (three stage improvement), B (two stage improvement), C (one stage improvement) and D (no change or worsened). Improvement of psychological symptoms was seen parallel to that of motor symptoms. It seems important that marked effect on both motor and psychological symptoms was obtained mostly in PD cases but not in the cases of JP. In MMPI test, depressive score (D) and hypochondriac score (Hs) were normalized in PD cases but not changed in JP, indicating differences in psychological traits between two groups. It was suggested that JP is a condition of mainly DA deficiency in nigro striatum but PD presents wider spectrum of symptoms covering both DA and NE deficiency. Importance of the role of aging of the brain in each individual patient is discussed and interpreted in relation to the difference of clinical pictures.