Eligibility Criteria:
INCLUSION
1. Adult participants who are cigarette smokers, 18-55 years of age.
2. Smokers: greater than 10 cigarettes/day.
3. Smoking for 1 year or longer.
4. Willingness to try to reduce or stay abstinent from cigarettes, smoking cessation aides (including nicotine gum or patches), smokeless tobacco, or electronic cigarettes for 3 weeks during the study.
5. Willingness to monitor sleep at home with an external device and maintain a simple sleep and smoking diary for 3 weeks.
6. Willingness to take a 5-min, mobile-based test 3X/day for 3 days/week during the 3 weeks.
7. Ability to travel to three Study Visits.
8. Are willing to abstain from consuming grapefruit products during the study.
9. Have an iPhone, best with iOS 17 or newer.
EXCLUSION:
1. Are currently taking any pharmaceutical drugs for smoking cessation, including: Nicotine patch or nicotine gum, buproprion (Wellbutrin, Zyban), varenicline (Chantix, Champix), other behavioral interventions such as cognitive behavioral therapy for smoking.
2. Are currently using cannabis or alcohol for sleep. Are currently taking any pharmaceutical drugs for insomnia, such as eszopiclone (Lunesta), zaleplon (Sonata) or zolpidem (Ambien, Ambien CR, Edluar, and Zolpimist) benzodiazepines, or opioids.
3. Are currently taking stimulants commonly used for ADHD, such as methylphenidate (Ritalin Concerta, Daytrana) or amphetamines (Adderall, Dexedrine, Vyvanse).
4. Are currently taking anti-seizure drugs, including lamotrigine, pregabalin (Lyrica), or gabapentin (Neurontin, Horizant, or Gralise).
5. Have non-nicotine substance dependence (diagnosed with substance use disorder, including alcohol or cannabis use disorder (current cannabis use is acceptable, and past illicit drug use is acceptable if greater than 2 months prior to testing and does not meet current criteria for substance use disorders (SUDs) according to DSM-5).
6. Have a major neurological disorder such as Parkinson's disease, epilepsy, Alzheimer's disease, multiple sclerosis, or any other serious neurological disorder.
7. Have a history of serious psychiatric disorders including bipolar disorder, schizophrenia, or suicidality.
8. Had a stroke or head injury which caused loss of consciousness for longer than three minutes in the past 1 year.
9. Are pregnant or breastfeeding.
10. Have been diagnosed with sleep apnea or other diagnosed sleep disorders such as narcolepsy.
11. Have been diagnosed with thyroid problems.
12. Have been diagnosed with COPD.
13. Have been doing variable shift work in the past 1 month or traveled more than 1 time zone in past month.
14. Are currently taking the following medications, supplements, or food: Daridorexant can interact with strong inhibitors of CYP3A4, which should be discussed with The Study Doctor's office (some of these include clarithromycin, diltiazem, erythromycin, itraconzale, ketoconazole, ritonavir, and verapamil).
15. Have a BMI of 33 or higher.