Source	Search strategy	Hits retrieved
1. ALOIS (www.medicine.ox.ac.uk/alois) [Date of most recent search: 8 August 2019]	Advanced search: (PDD OR PD OR Parkinson OR Parkinsons) AND Non‐pharmacological	Jan 2016: 26 Jan 2017: 0 Dec 2017: 0 Sep 2018: 2 Aug 2019: 6
2. MEDLINE In‐process and other non‐indexed citations and MEDLINE 1950‐present (Ovid SP) [Date of most recent search: 8 August 2019]	1. *Cognitive Therapy/ 2. (cognit* adj2 stimulation).ti,ab. 3. (cognit* adj2 rehabilitation).ti,ab. 4. (cognit* adj2 training).ti,ab. 5. (cognit* adj2 retrain*).ti,ab. 6. "cognitive support".ti,ab. 7. "memory function*".ti,ab. 8. (memory adj2 rehabilitation).ti,ab. 9. (memory adj2 therap*).ti,ab. 10. "memory aid*".ti,ab. 11. "memory group*".ti,ab. 12. "memory training".ti,ab. 13. ("memory retraining" or "memory re‐training").ti,ab. 14. "memory support".ti,ab. 15. "memory stimulation".ti,ab. 16. "memory strateg*".ti,ab. 17. "memory management".ti,ab. 18. or/1‐17 19. randomized controlled trial.pt. 20. controlled clinical trial.pt. 21. randomized.ab. 22. placebo.ab. 23. randomly.ab. 24. trial.ab. 25. groups.ab. 26. or/19‐25 27. (animals not (humans and animals)).sh. 28. 26 not 27 29. parkinson*.ti,ab. 30. exp Parkinson's Disease/ 31. exp Parkinsonism/ 32. PDD.ti,ab. 33. MCI‐PD.ti,ab. 34. PD‐MCI.ti,ab. 35. or/29‐34 36. 28 and 35	Jan 2016: 92 Jan 2017: 15 Dec 2017: 31 Sep 2018: 19 Aug 2019: 21
3. EMBASE 1974‐2017 December 10 (Ovid SP) [Date of most recent search: 8 August 2019]	1. (cognit* adj2 stimulation).ti,ab. 2. (cognit* adj2 rehabilitation).ti,ab. 3. (cognit* adj2 training).ti,ab. 4. (cognit* adj2 retrain*).ti,ab. 5. "cognitive support".ti,ab. 6. (memory adj2 rehabilitation).ti,ab. 7. (memory adj2 therap*).ti,ab. 8. "memory aid*".ti,ab. 9. "memory group*".ti,ab. 10. "memory training".ti,ab. 11. ("memory retraining" or "memory re‐training").ti,ab. 12. "memory support".ti,ab. 13. "memory stimulation".ti,ab. 14. "memory strateg*".ti,ab. 15. "memory management".ti,ab. 16. or/1‐15 17. randomly.ab. 18. placebo*.ti,ab. 19. "double‐blind*".ti,ab. 20. randomized controlled trial/ 21. trial.ti,ab. 22. or/17‐21 23. 22 and 16 24. parkinson*.ti,ab. 25. exp Parkinson's Disease/ 26. exp Parkinsonism/ 27. PDD.ti,ab. 28. MCI‐PD.ti,ab. 29. PD‐MCI.ti,ab. 30. or/24‐29 31. 22 and 30	Jan 2016: 36 Jan 2017: 13 Dec 2017: 23 Sep 2018: 35 Aug 2019: 36
4. PSYCINFO 1806‐December week 1 2017 (Ovid SP) [Date of most recent search: 8 August 2019]	1. (cognit* adj2 stimulation).ti,ab. 2. (cognit* adj2 rehabilitation).ti,ab. 3. (cognit* adj2 training).ti,ab. 4. (cognit* adj2 retrain*).ti,ab. 5. "cognitive support".ti,ab. 6. (memory adj2 rehabilitation).ti,ab. 7. (memory adj2 therap*).ti,ab. 8. "memory aid*".ti,ab. 9. "memory group*".ti,ab. 10. "memory training".ti,ab. 11. ("memory retraining" or "memory re‐training").ti,ab. 12. "memory support".ti,ab. 13. "memory stimulation".ti,ab. 14. "memory strateg*".ti,ab. 15. "memory management".ti,ab. 16. or/1‐15 17. randomly.ab. 18. randomi?ed.ab. 19. placebo*.ti,ab. 20. trial.ti,ab. 21. RCT.ti,ab. 22. groups.ab. 23. or/17‐22 24. 16 and 23 25. parkinson*.ti,ab. 26. exp Parkinson's Disease/ 27. exp Parkinsonism/ 28. PDD.ti,ab. 29. MCI‐PD.ti,ab. 30. PD‐MCI.ti,ab. 31. or/25‐30 32. 24 and 31	Jan 2016: 17 Jan 2017: 6 Dec 2017: 9 Sep 2018: 9 Aug 2019: 11
5. CINAHL (EBSCOhost) [Date of most recent search: 8 August 2019]	S1 (MH "Parkinson Disease") S2 TX Parkinson* S3 TX PDD S4 TX MCI‐PD S5 TX PD‐MCI S6 S1 OR S2 OR S3 OR S4 OR S5 S7 TX cognit* S8 (MM "Cognition") S9 TX (brain OR mental) AND (gam* OR exercis* OR puzzle* OR train* OR program*) S10 S7 OR S8 OR S9 S11 S6 AND S10 S12 (MH "Randomized Controlled Trials") S13 TX placebo S14 TX RCT S15 TX "double‐blind*" S16 TX "single‐blind*" S17 TX randomly S18 S12 OR S13 OR S14 OR S15 OR S16 OR S17 S19 S11 AND S18	Jan 2016: 461 Jan 2017: 33 Dec 2017: 65 Sep 2018: 83 Aug 2019: 153
6. Web of Science Core Collection [Date of most recent search: 8 August 2019]	((parkinson* dement*) OR PDD OR "MCI‐PD" OR "PD‐MCI") ANDTOPIC: ("cognit* train*" OR mental OR (brain* gam*) OR (brain exercis*) OR (memory exercis*) OR puzzle OR sudoku OR crossword*) ANDTOPIC: (randomly OR randomised OR randomized OR placebo OR "double‐blind*" OR trial OR RCT OR CCT) Timespan: All years. Search language=Auto	Jan 2016: 556 Jan 2017: 19 Dec 2017: 25 Sep 2018: 44 Aug 2019: 36
7. LILACS (BIREME) [Date of most recent search: 8 August 2019]	parkinson OR parkinsons OR PDD [Words] and cognition OR cognitive OR brain OR mental Or memory [Words] and randomly OR randomised OR randomized OR trial OR ensaio clínico OR control OR controlled [Words]	Jan 2016: 71 Jan 2017: 0 Dec 2017: 3 Sep 2018: 6 Aug 2019: 6
8. CENTRAL (the Cochrane Library) (Issue 11, 2019) [Date of most recent search: 8 August 2019]	#1 MeSH descriptor: [Parkinson Disease] explode all trees #2 parkinson* #3 PDD #4 MCI‐PD #5 PD‐MCI #6 #1 or #2 or #3 or #4 or #5 #7 MeSH descriptor: [Cognition] explode all trees #8 cognit* #9 "brain* train*" #10 "mental exercis*" #11 sudoku or puzzle* or crossword* or IQ #12 #7 or #8 or #9 or #10 or #11 #13 #6 and #12 in Trials	Jan 2016: 618 Jan 2017: 132 Dec 2017: 286 Sep 2018: 302 Aug 2019: 421
9. ClinicalTrials.gov (www.clinicaltrials.gov) [Date of most recent search: 8 August 2019]	[Condition: Parkinson OR parkinsons OR parkinson’s OR PD] AND [Intervention: cognitive training OR cognitive exercise OR brain training OR memory training OR memory exercise] limit to Interventional studies	Jan 2016: 0 Jan 2017: 0 Dec 2017: 14 Sep 2018: 11 Aug 2019: 0
10. ICTRP Search Portal (apps.who.int/trialsearch) [includes: Australian New Zealand Clinical Trials Registry; ClinicalTrilas.gov; ISRCTN; Chinese Clinical Trial Registry; Clinical Trials Registry – India; Clinical Research Information Service – Republic of Korea; German Clinical Trials Register; Iranian Registry of Clinical Trials; Japan Primary Registries Network; Pan African Clinical Trial Registry; Sri Lanka Clinical Trials Registry; The Netherlands National Trial Register] [Date of most recent search: 8 August 2019]	[Condition: Parkinson OR parkinsons OR parkinson’s OR PD] AND [Intervention: cognitive training OR cognitive exercise OR brain training OR memory training OR memory exercise] Recruitment status: all	Jan 2016: 56 Jan 2017: 26 Dec 2017: 2 Sep 2018: 7 Aug 2019: 6
TOTAL before de‐duplication and first assessment		3849
TOTAL after de‐duplication and first assessment by CDCIG Information Specialists		451