Doug Hoffman writes:

Define "anti-depressant drug". Drugs that are classically labelled as
anti-depressant are frequently used simply to treat various forms of
neuropathy (disease of peripheral nerve(s) causing a level of pain or
discomfort). No depression involved anywhere. The neuropathy is
often mild in nature and has absolutely no effect whatsoever on the
ability to safely pilot an aircraft (especially when the "anti-
neuropathy drug" is taken). Drugs don't know what they are supposed
to be "for". They are just chemical compounds with labels we give
them.

Some drugs are themselves prohibited because of side effects that may
interfere with flying. The reason for prescribing them is irrelevant in such
cases, as it is the use of the drug itself to which the FAA objects.

The FAA might also object to the condition being treated, but prohibitions on
specific conditions are independent of prohibitions on the medications
themselves. Either of these, or both, may interfere with obtaining a medical
certification.