C-SSRS rates an individual's degree of suicidal ideation (SI) on a scale, ranging from "wish to be dead" to "active suicidal ideation with specific plan and intent." The scale identifies SI severity and intensity, which may be indicative of an individual's intent to commit suicide. C-SSRS SI severity subscale ranges from 0 (no SI) to 5 (active SI with plan and intent).

SMWQ is a questionnaire to assess withdrawal symptoms subsequent to completion of dosing with Investigational medicinal product (IMP). The SMWQ is a modification of the Amphetamine Withdrawal Questionnaire, in which the first question "Have you been craving amphetamine or methamphetamine?" is replaced with "Have you been craving the trial medication?" This change is intended to prevent bias by implying that the trial medication might be an amphetamine or amphetamine-like stimulant when presented with the survey. Participants will complete the SMWQ onsite when they are at a designated trial visit; on days when the participant is not onsite, they will complete the SMWQ remotely.

The MDS-UPDRS is a multidimensional scale that assesses the motor and non-motor impacts of PD across 4 parts. Part I, non-motor aspects of experiences of daily living, comprises 13 items, 6 of which are rated by the physician (Part IA) and 7 of which are rated by the participant (Part IB). Part II, motor aspects of experiences of daily living, comprises 13 items that are rated by the participant. Part III, motor examination, comprises 18 items that are assessed by the investigator (resulting in 33 scores by location and lateralization). Part IV, motor complications, comprises 6 item (3 items for dyskinesia and 3 items for fluctuation) and requires the physician to use historical and objective information to assess dyskinesia and motor fluctuations. Each item of all the parts will be rated on a scale from 0 to 4 on which 0 = normal, 1=slight, 2=mild, 3=moderate, and 4=severe. Change from baseline in MDS-UPDRS parts I, II and III combined score will be assessed.

The Hauser diary (Hauser et al, 2000) assesses participant-defined clinical status over a period of time and provides a tool for assessment of the change in "off" time and "on" time with troublesome dyskinesia (which is a more accurate reflection of clinical response than "off" time alone). The Hauser diary asks participants to rate their mobility for each 30-minute period and to record their status for the majority of the period in 1 of 5 categories as: "on" time without dyskinesia, "on" time with nontroublesome dyskinesia, "on" time with troublesome dyskinesia, "off" time, or asleep.

EQ-5D-5L is a survey instrument used for participant-reported outcome that measures health in 5 dimensions. The EQ-5D-5L descriptive system comprises of 5 dimensions: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. Each has 5 levels of perceived problems (1 = no problem, 2 = slight problems, 3 = moderate problems, 4 = severe problems, 5 = extreme problems). Participant selects an answer for each of 5 dimensions considering the response that best matches his/her health "today". The digits for the 5 dimensions are combined into a 5-digit number that describes the participant's health state.

EQ-5D-5L VAS is a 2-part instrument for use as a measure of health outcome, designed for self-completion by respondents. The EQ-5D-5L VAS self-rating records the respondent's own assessment of his or her overall health status at the time of completion, on a scale of 0 (the worst health you can imagine) to 100 (the best health you can imagine).