Self-control: theory and research.

Theory and research on self-control were reviewed. Selected research is summarized along with some conclusions from clinical practice. Self-control difficulties are of central importance for many psychiatric disorders. Self-control is also a crucial, and often missing, ingredient for success in most treatment programs. It is stable enough to be considered an enduring trait or skill, but not immutable. Performance tests provide ingenious methods of measuring it, and they have some advantages over questionnaires. Biological research is under way: the prefrontal cortex is heavily involved; alcohol reduces self-control; serotonin may increase it. Self-control is correlated with, but not identical with, capacity for focused attention. Self-control is subject to "momentum effects": the more it is successfully practiced in a given arena, the easier subsequent practice usually becomes, and vice versa. Like a muscle, it appears to be fatigued in the short run and strengthened in the long run by exercise.