If and only if it's negatively self reinforcing. Which it might not be, if it's serving some purpose.

Self-harm can help you to feel in control, and reduce uncomfortable feelings of tension and distress. If you feel guilty, it can be a way of punishing yourself and relieving your guilt. Either way, it can become a 'quick fix' for feeling bad.

-- http://www.rcpsych.ac.uk/mentalhealthinfo/problems/depression/self-harm.aspx