The effect of 5-HTTLPR in moderating environmental influences in a manner consistent with differential susceptibility is not restricted to depression and its symptoms, but also—and perhaps unsurprisingly—to anxiety and ADHD. Gunthert et al.30 documented the former result in a longitudinal study of 350 college students. At study entry and a year later, participants reported anxiety and negative events daily for 30 days. Genotyping distinguished three alleles, but the LG allele was grouped with ‘s' alleles owing to its functional equivalence vis-à-vis promoter activity. Individuals judged homozygous for short alleles (including s/LG and LG/LG) reported more anxiety in the evening when daily-event stress was high compared with individuals with different genotypes, but also less anxiety than other genotypes when experiencing little daily-event stress, a pattern consistent across measurement occasions. Once again the fact that the susceptibility factor did not predict the environmental measure or the outcome is considered important.
