A few studies have conducted linkage analyses using cannabis dependence, cannabis dependence symptoms, and cannabis dependence subtypes as phenotypes [see Hopfer et al., 2007; Agrawal et al., 2008a,b; Ehlers et al., 2009], and some significant loci have been identified. Yet no studies to date have conducted linkage analyses using cannabis withdrawal and/or craving phenotypes. The aim of the present set of analyses was to identify loci associated with cannabis dependence, withdrawal and craving in the UCSF Family Alcoholism Study. The UCSF Family Alcoholism Study is a project that was designed to identify genetic loci that influence susceptibility to alcohol dependence and related phenotypes. It used a small family design, focusing primarily on sibling pairs and parent-child trios. The study enrolled 2454 individuals from 970 families from December 1995 through January 2003. Test-retest and inter-rater reliability for clinical data have been shown to be very good [Vieten et al., 2004]. Design, methods, recruitment strategies and sample demographics of the UCSF Family Alcoholism Study have been presented previously [see Seaton et al., 2004; Vieten et al., 2004], along with intrafamilial correlations for primary diagnostic phenotypes.
