Some psychiatrists refuse to authorize or look at those tests. I had one like that, so I had to switch to a different psychiatrist who would look at it.

I used the GeneSight website to find a provider who would agree to do testing: Find a Provider | GeneSight

The test confirmed what I had already learned the hard way: that SNRIs work better for me than SSRIs. I wish that test had been around in the 90s when I first started taking meds. Would have saved me a lot of painful side effects.