I stopped taking it because it made me emotionally numb. Once I got on what was a therapeutic dose, I had low potassium so I started having to take potassium pills. And so numb, no emotions. If I stubbed my toe I'd just say "ow" not scream or react. When I failed a class, I was like "oh well." That's when I knew I needed something else.
It's an old drug, so it's cheap, and the side effects are known.
Honestly, there are better drugs with fewer side effects for depression, from SSRIs to SNRIs.