Parkinson's Disease

    Written by:
    Bill Willis

    Fact-checked

    by:

    Louie Neri, Graham Walker
    Last Updated: March 27, 2025

    Parkinson’s disease is a neurodegenerative disease caused by progressive loss of dopamine-producing neurons in the brain. Symptoms are mild at first, but progress over time, leading to impaired movement as well as other neurocognitive and psychiatric symptoms like depression, dementia, bowel and bladder problems, and difficulty sleeping.

    74 references on this page
    6,468 participants in 14 trials and 6 meta-analyses

    Overview

    Examine Database: Parkinson's Disease

    Research FeedRead all studies

    Frequently asked questions

    Examine Database References

    1. Subjective Well-Being - Bender A, Koch W, Elstner M, Schombacher Y, Bender J, Moeschl M, Gekeler F, Müller-Myhsok B, Gasser T, Tatsch K, Klopstock TCreatine supplementation in Parkinson disease: a placebo-controlled randomized pilot trialNeurology.(2006 Oct 10)
    2. Parkinson's Disease Symptoms - Writing Group for the NINDS Exploratory Trials in Parkinson Disease (NET-PD) Investigators, Kieburtz K, Tilley BC, Elm JJ, Babcock D, Hauser R, Ross GW, Augustine AH, Augustine EU, Aminoff MJ, Bodis-Wollner IG, Boyd J, Cambi F, Chou K, Christine CW, Cines M, Dahodwala N, Derwent L, Dewey RB Jr, Hawthorne K, Houghton DJ, Kamp C, Leehey M, Lew MF, Liang GS, Luo ST, Mari Z, Morgan JC, Parashos S, Pérez A, Petrovitch H, Rajan S, Reichwein S, Roth JT, Schneider JS, Shannon KM, Simon DK, Simuni T, Singer C, Sudarsky L, Tanner CM, Umeh CC, Williams K, Wills AMEffect of creatine monohydrate on clinical progression in patients with Parkinson disease: a randomized clinical trialJAMA.(2015 Feb 10)
    3. Parkinson's Disease Symptoms - Mo JJ, Liu LY, Peng WB, Rao J, Liu Z, Cui LLThe effectiveness of creatine treatment for Parkinson's disease: an updated meta-analysis of randomized controlled trials.BMC Neurol.(2017-Jun-02)
    4. Parkinson's Disease Symptoms - Xiao Y, Luo M, Luo H, Wang JCreatine for Parkinson's disease.Cochrane Database Syst Rev.(2014-Jun-17)
    5. Power Output - Hass CJ, Collins MA, Juncos JLResistance training with creatine monohydrate improves upper-body strength in patients with Parkinson disease: a randomized trialNeurorehabil Neural Repair.(2007 Mar-Apr)
    6. Parkinson's Disease Symptoms - Phillips MCL, Murtagh DKJ, Gilbertson LJ, Asztely FJS, Lynch CDPLow-fat versus ketogenic diet in Parkinson's disease: A pilot randomized controlled trialMov Disord.(2018 Aug)
    7. Uric Acid - Gohari S, Ghobadi S, Jafari A, Ahangar H, Gohari S, Mahjani MThe effect of dietary approaches to stop hypertension and ketogenic diets intervention on serum uric acid concentration: a systematic review and meta-analysis of randomized controlled trials.Sci Rep.(2023 Jun 28)
    8. Parkinson's Disease Symptoms - C B Carroll, P G Bain, L Teare, X Liu, C Joint, C Wroath, S G Parkin, P Fox, D Wright, J Hobart, J P ZajicekCannabis for dyskinesia in Parkinson disease: a randomized double-blind crossover studyNeurology.(2004 Oct 12)
    9. Parkinson's Disease Symptoms - Katzenschlager R, Evans A, Manson A, Patsalos PN, Ratnaraj N, Watt H, Timmermann L, Van der Giessen R, Lees AJMucuna pruriens in Parkinson's disease: a double blind clinical and pharmacological studyJ Neurol Neurosurg Psychiatry.(2004 Dec)
    10. Parkinson's Disease Symptoms - Roberto Cilia, Janeth Laguna, Erica Cassani, Emanuele Cereda, Nicolò G Pozzi, Ioannis U Isaias, Manuela Contin, Michela Barichella, Gianni PezzoliMucuna pruriens in Parkinson disease: A double-blind, randomized, controlled, crossover studyNeurology.(2017 Aug 1)
    11. Parkinson's Disease Symptoms - Roberto Cilia, Janeth Laguna, Erica Cassani, Emanuele Cereda, Benedetta Raspini, Michela Barichella, Gianni PezzoliDaily intake of Mucuna pruriens in advanced Parkinson's disease: A 16-week, noninferiority, randomized, crossover, pilot studyParkinsonism Relat Disord.(2018 Apr)
    12. Parkinson's Disease Symptoms - Müller T, Büttner T, Gholipour AF, Kuhn WCoenzyme Q10 supplementation provides mild symptomatic benefit in patients with Parkinson's diseaseNeurosci Lett.(2003 May 8)
    13. Parkinson's Disease Symptoms - Zhu ZG, Sun MX, Zhang WL, Wang WW, Jin YM, Xie CLThe efficacy and safety of coenzyme Q10 in Parkinson's disease: a meta-analysis of randomized controlled trials.Neurol Sci.(2017-Feb)
    14. Parkinson's Disease Symptoms - Gelfin E, Kaufman Y, Korn-Lubetzki I, Bloch B, Kremer I, Javitt DC, Heresco-Levy UD-serine adjuvant treatment alleviates behavioural and motor symptoms in Parkinson's diseaseInt J Neuropsychopharmacol.(2012 May)
    15. Heart Rate - Joanne DiFrancisco-Donoghue, Ely Rabin, Eric M Lamberg, William G WernerEffects of Tyrosine on Parkinson's Disease: A Randomized, Double-Blind, Placebo-Controlled TrialMov Disord Clin Pract.(2014 Oct 23)
    16. Orthostatic Hypotension Symptoms - Shibao C, Okamoto LE, Gamboa A, Yu C, Diedrich A, Raj SR, Robertson D, Biaggioni IComparative efficacy of yohimbine against pyridostigmine for the treatment of orthostatic hypotension in autonomic failureHypertension.(2010 Nov)
    17. Depression Symptoms - A Di Rocco, J D Rogers, R Brown, P Werner, T BottiglieriS-Adenosyl-Methionine improves depression in patients with Parkinson's disease in an open-label clinical trialMov Disord.(2000 Nov)
    18. Depression Symptoms - Meloni M, Puligheddu M, Carta M, Cannas A, Figorilli M, Defazio GEfficacy and safety of 5-hydroxytryptophan on depression and apathy in Parkinson's disease: a preliminary finding.Eur J Neurol.(2020 May)
    19. Depression Symptoms - Alnajjar AZ, Abouelmagd ME, Krayim A, AbdelMeseh M, Bushara N, Nabil YEfficacy of cognitive behavioral therapy for anxiety and depression in Parkinson's disease patients: an updated systematic review and meta-analysis.Neurol Sci.(2024 Jul 3)
    20. Depression Symptoms - Seok JW, Kim JDLight Therapy for Older People with Depressive Symptoms: Systematic Review and Meta-Analysis.J Clin Med.(2024 Nov 20)