Please assess the completion status of the following clinical trial:

Trial Title: An fMRI Study of Opioid-related Changes in Neural Activity

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

Eligibility Criteria:
Inclusion Criteria:~* good health~* between the ages of 18 and 35,~* fluent in English~* right-handed (for the fMRI scan)~Exclusion Criteria:~* Self-reported current or past diagnoses of physical or mental illness.~* Score on the Patient Health Questionnaire (depressive symptoms) above a 13~* Positive urine drug test (for Tetrahydrocannabinol (THC), Opiates, Cocaine, Amphetamine (AMP), and Methamphetamine (mAMP))~* Positive urine pregnancy test~* Use of any prescription medication, except for birth control~* Use of any over-the-counter medications on the day of the fMRI session and 24 hours after the fMRI session~* Self-reported problems with liver functioning, including hepatitis or liver failure~* Difficulty swallowing or taking pills~* BMI greater than 35 or weight greater than 400 lbs~* Claustrophobia~* Nonremovable metal in the body

- Gender: ALL
- Minimum Age: 18 Years
- Maximum Age: 35 Years
- Healthy Volunteers: t

Study Arms:
- naltrexone (Type: EXPERIMENTAL): single 50mg dose of naltrexone
- sugar pill (Type: PLACEBO_COMPARATOR): single sugar pill

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