Alternatively, specific comorbidities or markers of overall severity may moderate the strength of the relationship between 5HTTLPR and alcohol dependence. However, within the study of alcohol dependence, there has been inconsistency in findings of the role of comorbid depression reflected the overall literature (Reich et al., 2009), with an association between the s allele and comorbid depression in some (Gokturk et al., 2008; Marques et al., 2006; Nellissery et al., 2003) but not other studies of alcohol dependent samples (Gorwood et al., 2000). Such inconsistency may imply that diagnostic status is the wrong level of analysis for whatever risk the s allele may confer. Further evaluation of emotion regulation factors (e.g., amygdala activation, HPA axis activation, anxiety sensitivity, and attentional vigilance) may be a much more fruitful direction for future research.
