Perhaps most importantly, the definition of craving is known to have a significant impact on its psychometric relationship with the construct of dependence – we used a single item that approximates the proposed DSM-5 criteria, however more work is required to outline whether this definition of craving is optimal for diagnostic purposes and for genetic analysis. The single craving item was employed in both a family-based study of European subjects in which it was associated with SNPs in SNCA (Foroud et al, 2007) as well as in a family-based linkage study of Mission Indians, which estimated the heritability of craving using this singe item to be 65% (Ehlers & Wilhelmsen, 2005).
