Eligible participants, who participated in the ADAGIO trial and who sign an approved informed consent form, will be enrolled into the study at their original study locations. participants who have stopped rasagiline therapy and in the opinion of the investigator will gain clinical benefit from restarting treatment can also be considered for enrollment in the Core follow-up study period. Use of any other anti-PD treatment is permitted as deemed necessary by the treating physician (according to the participants clinical status).

Inclusion Criteria:

1. Subjects who participated in the ADAGIO study, and who entered the active phase of the study and
2. Subjects who are currently on rasagiline treatment (or subjects who have stopped rasagiline treatment, are willing to restart treatment, and in the opinion of the investigator will gain clinical benefit from restarting treatment) and
3. Subjects with a diagnosis of Parkinson's disease and
4. Subjects willing and able to give written informed consent

Exclusion Criteria:

1. Subjects who have discontinued rasagiline treatment due to an adverse event and have not restarted rasagiline treatment subsequently.
2. Subjects who cannot be given rasagiline due to any exclusion based on the local label (including pregnancy or nursing women) or due to the use of medications contraindicated for concomitant use with rasagiline according to local label
3. Subjects with a medical condition that is considered by the investigator as significant enough to prevent participation

Only those who participated in the ADAGIO trial, and who sign an approved informed consent form, will be included in the follow-up study