The Biological Approach

• Initiation - evidence of genetic transmission of gambling in men (Shah et al., 2005); first degree relatives of gamblers more likely to gamble than distant relatives (Black et., 2006).
• Maintenance - pathological gambling associated with underactive pituitary-adrenal system (Paris et al., 2010). Individual differences in optimal amounts of stimulation (Zuckerman, 1979).
• Blaszczynski et al. (1990) - poor boredom tolerance may contribute to repetitive gambling.

Evaluation

• Can explain individual differences in gambling addiction through diasthesis-stress model.
• Biological approach ignores importance of external factors in development of gambling addiction. 
• Cannot explain why some types of gambling (e.g. online and video gambling) are more addictive than others (Breen and Zimmerman, 2001).
• Sensation seeking explains racetrack gambling but not cafe gambling (Bonnaire et., 2006).
• Biological explanations are reductionist and determinist.

• Initiation - individual differneces in smoking initiation 42-44% genetic (Boardman et al., 2008; Vink et al., 2005).  

• Maintenance - Vink et al. estimate nicotine dependence 75% genetic and linked to individual differences in nicotine metabolism. Pre-natal exposure to nicotine important in determining later addiction (Buka et al., 2003).    

• Relapse - Xian et al., (2003) found ability to quit smoking is also sibstantially heritable. Uhl et al. (2008) attempted to identify gene clusters assoicated with quit success and nicotine dependence.

Evaluation  

• Supporting evidence for genetic influence on smoking - Thorgeirsson et al. (2008) identified gene variant on chromosome 15.

• Biological explanations neglect other possible determing factors, including social context fo smoking.

• Genomic medicine - screening to identify those with genes that increase susceptibility tosmoking addiction. Gartner et al. (2009) - screening for susceptibilty unlikely to be practical.

• Asp40 variant less likely to quit with low dose NRT - genetic testing might allow therapists to match cessation therapy with genotype (Lerman et al., 2004).