After having experimented occasionally with MPD over decades - long before being diagnosed with so-called "PD" - and now whilst having standard PD symptoms, I encourage the curious PwP to try methylphenidate to see if you get what are sometimes immediate and phenomenally positive effects on energy, mood, strength, mobility. With the usual caveats ...
5 mg is enough in my case for effects that begin in 20 minutes and last 3.5 - 4 hours.
There's a lot of pretty good support for methylphenidate in "PD". Here's one of many studies:
Neuropharmacol. 2008 Dec; 6(4): 379–385.
Neuropharmacological Mechanisms Underlying the Neuroprotective Effects of Methylphenidate
T.J Volz*
Extract (Full article at link):
Abnormal cytoplasmic DA accumulation may also contribute to the development of Parkinson’s disease [5, 22], suggesting the possibility that MPD may be neuroprotective in this disease state as well since MPD treatment has been shown to improve motor function in human Parkinson’s patients [9]. Additionally, MPD provides protection from the behavioral and neurochemical effects of 6-hydroxydopamine in an animal model of Parkinson’s disease [14]. As detailed below, these neuroprotective effects of MPD may be due, at least in part, to its ability to attenuate or prevent abnormal cytoplasmic DA accumulation in dopaminergic neurons by modulating the activity of the DAT and the VMAT-2 through several neuropharmacological mechanisms.
ncbi.nlm.nih.gov/pmc/articl...
Edit: Ritalin is methylphenidate.