Please assess the completion status of the following clinical trial:

Trial Title: Extended-Release Melatonin in Patients With Rapid Eye Movement Sleep Behavior Disorder

Study Design Characteristics:
- Allocation: RANDOMIZED
- Intervention Model: CROSSOVER
- Observational Model: None
- Primary Purpose: SUPPORTIVE_CARE
- Time Perspective: None
- Masking: DOUBLE
- Phase: None
- Number of Arms: 2.0

Eligibility Criteria:
Inclusion Criteria:~* Diagnosed with Parkinson's disease and rapid eye movement sleep behavior disorder.~* Patient registered to Parkinson's disease database of Mayo Clinic Florida.~Exclusion Criteria:~* Patients who are using other sleep aids or medications (Clonazepam).~* Patients who are not willing to undertake 1 week of washout period.~* Patients who do not sign a consent for research.

- Gender: ALL
- Minimum Age: 18 Years
- Maximum Age: None
- Healthy Volunteers: f

Study Arms:
- Immediate Release Melatonin, Then Extended Release Melatonin (Type: EXPERIMENTAL): Subjects will receive immediate release melatonin 5 mg orally at 9 pm every night for 4 weeks. After a washout period of 2 weeks, they then receive extended release melatonin 5 mg orally at 9 pm every night for 4 weeks.
- Extended Release Melatonin, Then Immediate Release Melatonin (Type: EXPERIMENTAL): Subjects will receive extended release melatonin 5 mg orally at 9 pm every night for 4 weeks. After a washout period of 2 weeks, they then receive immediate release melatonin 5 mg orally at 9 pm every night for 4 weeks.

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