For others, however, this harmless behavior crosses the line into a compulsive activity that is anything but benign. Some become so dependent on the behavior that they lose hours and hours of their day, unable to leave the house. Others masturbate to the point of injuring themselves.
Choosing masturbation over intimate relationships, the person can become isolated, or end up spending all their time and money on porn to further fuel their compulsive behavior. Still others become addicted to the point where they find themselves unable to control the urge to masturbate in public or otherwise inappropriate places. This is addiction, and it can have just as grave, debilitating consequences as drugs or alcohol.
Source: Childhood Trauma and Masturbation | Psychology Today