In what form are the changes? You say emotionally blunted? In what way?
Are the meds dealing with your depression? Do you feel "less" depressed?
Have you been diagnosed correctly? Depression can co-exist with other mental issues, or indeed be a part of Bi-Polar disorder. Anti-depressants used without other medications in Bi-Polar can cause problems.
I speak as a Bi-Polar sufferer who uses a high dose of Sertraline as part of his treatment. Yes, I identify with what you say about Sertraline but it is better than staring into the darkness...