There are 4 DMDs that you might be prescribed, known as the CRAB drugs. These are
Copaxone, Rebif, Avonex
and Betaseron. The latter 3 are drugs of the type known as interferons, and interferons can cause depression in some (not most) patients. These 3 differ from one another in the manner and timing of injections, also in their strength, but their method of activity in the body is basically the same.