Depression is often caused by a lack of dopamine going to the brain, the lower dopamine levels make you feel sad.
So, Medication has been made to increase the dopamine your body sends to your brain.
However, that said...
I have had 2 family members take depression medications, and it caused one of them go to insane and commit suicide.
And the other had horrendous visions and voices in her head telling her to kill herself.
As my aunt tried to take her to the hospital, someone had to restrain her from jumping out of the car.
So, make sure if you take these medications you aren't home alone on your first few times