Please assess the completion status of the following clinical trial:

Trial Title: Nicotine and Behavior in Adult ADHD

Study Design Characteristics:
- Allocation: RANDOMIZED
- Intervention Model: CROSSOVER
- Observational Model: None
- Primary Purpose: BASIC_SCIENCE
- Time Perspective: None
- Masking: DOUBLE
- Phase: None
- Number of Arms: 1.0

Eligibility Criteria:
Inclusion Criteria:~* An age of 18 to 45 years~* A history of ADHD~* Current diagnosis of ADHD according to clinical criteria~* Being a smoker who smokes at least 10 cigarettes per day with 0.5 mg of nicotine per cigarette; OR~* Being a nonsmoker who has been abstaining from smoking and other nicotine products for the last 2 years~Exclusion Criteria:~* Treatment for any chronic illness such as heart disease, irregular heartbeat, high blood pressure, diabetes, skin allergies or skin diseases, including psoriasis or eczema, even if currently controlled by medication~* Current pregnancy, as measured by a pregnancy test (Clear Blue Easy, Unipath, Bedford, UK), or planning to become pregnant within the next 6 months. These individuals will not be included as the nicotine patch may cause harm to the unborn fetus~* Nursing mothers, or women who have breastfed within the last 12 months~* Non-English speaking people, because the majority of measurements used in the study have not been validated in languages other than English~* Current major depressive episode according to clinical criteria~* Concurrent psychiatric psychoactive medication within the past 12 months~* Active substance abuse within the past 12 months

- Gender: ALL
- Minimum Age: 18 Years
- Maximum Age: 45 Years
- Healthy Volunteers: f

Study Arms:
- 4 (Type: EXPERIMENTAL): None

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