{{Genotype
|rsid=2032583
|allele1=T
|allele2=T
|magnitude=2
|repute=Bad
|summary=7x less likely to respond to certain antidepressants.
}}
This version of a blood brain barrier protein blocks many common antidepressants from entering the brain, including: amitriptyline (Elavil), citalopram (Celexa), paroxetine (Paxil), and venlafaxine (Effexor). That makes those antidepressants 7 times less effective.