Joel Killen
Academic Appointments
- Professor Emeritus, Medicine - Stanford Prevention Research Center
- Emeritus Faculty, Acad Council, Medicine - Stanford Prevention Research Center
- Member, Stanford Cancer Institute
Key Documents
Contact Information
- Academic Offices
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Professional Overview
Honors and Awards
- Fellow, Society of Behavioral Medicine (Since 1992)
Community and International Work
- Family-based nutrition intervention for Latino children, Bay Area&suffix=researcher
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Scientific Focus
Current Research Interests
Drug addictions are viewed as chronic, relapsing disorders that may require extended therapy and follow-up. However, very few smoking cessation trials have examined the utility of extended therapy models. In a recently completed trial we attempted to boost long-term abstinence rates by extending the course of therapy. 362 adult smokers received 11 weeks of therapy that combined nicotine replacement, bupropion and behavioral therapy followed by an additional 14 weeks of therapy with bupropion or matching placebo. 52% were abstinent at 11 weeks. This result is almost double the mean treatment response (27%) typically observed for nicotine patch therapy. The overall abstinence rate at 25 weeks was about 40%, nearly twice the 24-week follow-up response observed in nicotine patch studies (21%). Abstinence percentages at week 52 (30%+) also represent a better-than-average treatment response.
We are now conducting a randomized clinical trial to examine the efficacy of a selegiline transdermal system in promoting cigarette smoking cessation.This is the first trial to examine this medication, developed as a treatment for Parkinsons disease, as a possible therapy for nicotine dependence. We are interested in selegiline as a smoking cessation therapy because this medication potentiates dopamine through inhibition of MAO-B. Our interest in this medication derives from evidence suggesting that (1) the positive reinforcing effects of addictive drugs play an important role in maintaining drug use; (2) facilitation of dopaminergic neurotransmission in the mesocorticolimbic dopamine system appears to be critical for the acute reinforcing actions of stimulant drugs including nicotine and (3) the craving which produces relapse reflects memory of dopamine- mediated positive reinforcement. The choice of selegiline is based on the rationale that a medication that can potentiate dopamine may thus help to alleviate craving to take a drug for its positive reinforcing effects.
Finally, we are exploring genetic factors that may influence response to treatment. In each of the studies described above smokers are genotyped for polymorphisms at loci hypothesized to affect nicotine dependence and/or treatment efficacy to determine if polymorphisms at these loci affect relapse rate in smokers.
Publications
- Markers in the 15q24 nicotinic receptor subunit gene cluster (CHRNA5-A3-B4) predict severity of nicotine addiction and response to smoking cessation therapy. Am J Med Genet B Neuropsychiatr Genet. 2011; (3): 275-84
- Predicting successful 24-hr quit attempt in a smoking cessation intervention. Nicotine Tob Res. 2011; (11): 1092-7
- Using treatment process data to predict maintained smoking abstinence. Am J Health Behav. 2010 Nov-Dec; (6): 801-10
- A randomized controlled trial of culturally tailored dance and reducing screen time to prevent weight gain in low-income African American girls: Stanford GEMS. Arch Pediatr Adolesc Med. 2010; (11): 995-1004
- Failure to improve cigarette smoking abstinence with transdermal selegiline + cognitive behavior therapy. Addiction. 2010; (9): 1660-8
- Perceived drug assignment and treatment outcome in smokers given nicotine patch therapy. J Subst Abuse Treat. 2010; (2): 150-6
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