Smoking Cessation & Opioid Dependence Treatment Integration

Inclusion Criteria: * enrolled in the Comprehensive Opioid Addiction Treatment (COAT) program * report smoking \>10 cigarettes per day for \>1 year * provide an expired air carbon monoxide (CO) reading of \>10 parts/million (ppm) * report interest in making a quit attempt in the next 1-6 months (Contemplation or Preparation stages via the Stage of Change; Prochaska \& Diclemente, 1983) * willing to try varenicline for smoking cessation Exclusion Criteria: * current engagement in any form of tobacco cessation (e.g., pharmacotherapy) * current use of contraindicated medications (e.g., theophylline, warfarin, insulin) * Stage of Change category as Precontemplation (no plans to quit), Action (actively trying to quit), or Maintenance (have already quit) * self-reported seizures in the past year * untreated cardiovascular disease * self-report breast-feeding * pregnancy (verified by urinalysis) * not within 4 weeks of advancing to the next COAT group