Yes.
Two different experiences: My first experience with therapy made me worse. The therapist didn't understand my problems or how to help. But instead of saying so, she acted like she understood and gave bad advice. I didn't see her for long enough to be too negatively affected, but already the short time with her made me feel worse, especially since I thought if it doesn't work for me, it's my fault, as if there's something wrong with me.
Then my current therapist and I have been working together for two years. Currently I'm doing better, but initially I felt quite a bit worse than before starting therapy. My T said this happens for some people.