MMPI differences among mild and severe insomniacs and good sleepers.

Past research has attempted to delineate personality differences between insomniacs and good sleepers but has failed to control for type of insomnia or severity of the disorder. The purpose of this study was to compare MMPI scores of mild and severe sleep onset insomniacs with a control group of noninsomniacs . Results demonstrated that sleep onset insomniacs, regardless of degree of severity, differed significantly from noninsomniacs ; and that mild and severe insomniacs differed from each other on only one MMPI scale.