Please assess the completion status of the following clinical trial:

Trial Title: The Effect of Methylphenidate on Non-motor Symptoms and Postural Control in Parkinson's Disease.

Study Design Characteristics:
- Allocation: RANDOMIZED
- Intervention Model: CROSSOVER
- Observational Model: None
- Primary Purpose: TREATMENT
- Time Perspective: None
- Masking: DOUBLE
- Phase: PHASE4
- Number of Arms: 4.0

Eligibility Criteria:
Inclusion Criteria:~* Patients with stages 2-3 Parkinson's disease as defined by the Hoehn \&Yahr staging system (Hoehn \&Yahr, 1967).~* Age less than or equal to 75 years.~* Subjects who are willing and able to provide, in writing, informed consent.~* Subjects who are willing and able to be confined to the clinical research unit as required by the protocol and to complete all procedures required on an outpatient basis.~Exclusion Criteria:~* Subjects with evidence or history of clinically significant hematological, renal, endocrine, pulmonary, gastrointestinal, cardiovascular, hepatic, psychiatric, neurological, or allergic disease (including drug allergies and excluding seasonal allergies).~* Subjects with a history of substance abuse or dependence or a positive urine screen for drugs of abuse.~* A history of regular alcohol consumption exceeding 7 drinks/week for women or 14 drinks/week for men (1 drink = 5 ounces of wine or 12 ounces of beer or 1.5 ounces of hard liquor) within 6 months of screening.~* Subjects with a documented allergy to methylphenidate or one of the product excipients.~* Subjects with any medical condition affecting drug absorption (e.g. gastrectomy).~* Treatment with an investigational drug within 30 days or 5 half-lives (whichever is longer) preceding the first dose of study medication.~* Use of a monoamine oxidase inhibitor or other interacting medication within the preceding 14 days or 5 half-lives (whichever is longer).~* History of sensitivity to heparin or heparin-induced thrombocytopenia.

- Gender: ALL
- Minimum Age: None
- Maximum Age: 75 Years
- Healthy Volunteers: f

Study Arms:
- Methylphenidate 10 (Type: EXPERIMENTAL): Methylphenidate 10mg three times daily for a total of 7 doses.
- Placebo 10 (Type: PLACEBO_COMPARATOR): Placebo capsule three times daily for a total of 7 doses.
- Methylpheindate 20 (Type: EXPERIMENTAL): Methylphenidate 20mg three times daily for a total of 7 doses.
- Placebo 20 (Type: PLACEBO_COMPARATOR): Placebo capsule three times daily for a total of 7 doses.

Based on this trial design, predict the completion outcome and termination type (if applicable).