Abstract: Pharmaceutical compositions of (R)-pramipexole and one or more secondary therapeutic agents such as, for example, dopamine agonists, dopaminergic agonists, COMT inhibitors, MOA inhibitors, excitatory amino acid antagonists, growth factors, neurotrophic factors, antioxidants, anti-inflammatory agents, immunomodulators, anti-glutamatergics, ion channel blockers, ?-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor antagonists, heat shock protein inducers/protein disaggregators and downregulators, monoamine oxidase type B (MOAB) inhibitors, multi-target agents, kinase inhibitors, Bcl inducers, histone deacetylase (HDAC) mediators, glial modulators, mitochondrial energy promoting agents, myostatin inhibitors, caspase inhibitors and combinations thereof or those related to mitochondrial dysfunction or increased oxidative stress are disclosed.