Variation on the serotonin transporter gene and bias in the interpretation of ambiguity

Previous studies have established that carriers of the low expression form of the serotonin transporter gene have an early attentional bias towards threatening relative to benign or positive information, in contrast to those with a high expression form of this gene. In the present study we extend this finding of a link between variation on the serotonin transporter gene and attentional bias to biases in the interpretation of emotional ambiguity. Specifically, a series of homophones were verbally presented (e.g., PAIN/PANE) and in line with research on attentional bias, participants with a low expression form of the serotonin transporter were more likely to select the threatening meaning more than those with a high expression form of the gene. This is the first evidence that variation on the serotonin transporter gene is correlated with interpretative bias and further strengthens the proposal that genetic variation, like processing bias, may play a role in the development and maintenance of emotional disorders.