My boyfriend has been on an anti-depressant for many years. I have noticed that he has no sexual desire and he has difficulty maintaining an erection. Is there a remedy for this?

Unfortunately, the majority of medications used to treat depression, schizophrenia and anxiety cause a decrease in libido. Moreover, most men lose their ability to have a prolonged erection. 

There are several ways to get around this problem. One may be to lower the dose of his antidepressant but this usually does not work well because the mental symptoms immediately come back. Your doctor may want to switch him to another antidepressant with lower risk of sexual side effects. 

Wellbutrin appears to be a good alternative in some people. The other more practical solution is to use medications like Viagra. There are several impotence medications that can potentiate an erection besides Viagra and they all work similarly. 

There are also cheap generic versions of Viagra but most of these never work. Moreover, on the internet many generic Viagra pills are fake so be careful where you buy your pills from. Finally Viagra and other similar pills are also expensive and can cost  anywhere from $2-$4 per tablet. If you are going to buy such pills from cyberspace pharmacies, avoid all international dealers because they are all scams.