An addiction—a persistent need to consume a substance or commit an act—is distinct from a compulsion, which is an overwhelming and irresistible impulse to act. Usually, a compulsive act is preceded by obsessive, intrusive thoughts that compel the person to act, whereas an addiction is more of a habit that is not necessarily accompanied by obsessive thinking. An individual experiencing either addiction or compulsions may find it helpful to speak to a mental health professional.