Nuanced website about the relation between serotonin transporter polymorphism and depression. The website was produced as an assignment for an undergraduate course at Davidson College. The title is: 5-HTT: The Gene for Susceptibility to Depression?
It clearly explains polymorphism and the relation with disease. Another important topic on this web page is the relation between a scientific publication and the reproduction of the results in a newspaper. The article describes the differences in interpretation between the two media.
In another article on Biology News it is explained how antidepressants block the transporter.
the drug binds to the outside of the transporter, changing its shape. This traps the brain chemical inside the tunnel like a cork in a bottle, preventing it from passing through to the inside of the neuron.