If you can find a very thick purple book titled "Physician's Drug Manual 1986" it had a listing of atypical antidepressants including 'alprazolam' aka xanax.

I don't think alprazolam was given up as an antidepressant because of efficacy issues, I believe the issues were dependence and the fact benzo withdrawals can be deadly.

Another issue might have been that benzo therapy tends to require upping the dose periodically, which can become a horrible ever increasing escalation. I think many psychiatrists are biased towards drugs that don't have any life threatening effects when discontinued.

Benzo discontinuation tends towards life threatening when compared to almost all other drugs. Benzos, barbiturates, alcohol- withdrawal from any of these is exponentially more risky than withdrawal from heroin. Heroin withdrawal makes you wish you'd die. without extreme complications heroin withdrawal will not kill you.

Benzo, barbiturate, and alcohol withdrawal all can kill.