Brett Persistently Injects Himself with Pain Killers

Brett persistently injects himself with pain killers. This has greatly increased his chance of overdosing and dying. His behavior harms no one else. According to the DSM-5, is Brett's behavior consistent with the definition of a mental disorder?

A) Yes, because many people in society engage in this behavior.
B) Yes, because he is persistently acting in a way that harms him.
C) No, because his behavior must also harm the well-being of others in the community.
D) No, because there is no evidence that his actions are out of his own control.