Yeah, so some people with extreme depression might benefit from taking a serotonin drug. But to use the drug off label is a big danger due to the side effects and the potential that they not ever go away. Yes everyone is a little bit different but we are all humans-- and the usual side effects they found in the 1980s are still around for people who take them in 2020.
PLUS we have to be skeptical of a drug, of 1 pill, being able to be THE solution to the problem.
Depression and mental illness are biopsychosocialbehavioral disorders, not just neurological/brain ones. Good psychotherapy like CBT ACT DBT is better than taking pills and does not do biological harm to the body.