Effect of depression on neuropsychological functioning in head injury: measurable but minimal

The goals of the study were to determine how neuropsychological functioning is related to depressive status in persons with head injury, and to quantify this relationship from a clinically relevant standpoint. Participants were 175 adults involved in litigation, referred for evaluation of suspected head injury. Depression status was measured using the Depression Content (Dep) scale of the MMPI-2. Depression status was related to measures of visual attention and psychomotor skills, but not to other neuropsychological domains such as verbal ability, visual-spatial reasoning, or encoding/organization. However, differences between low Dep and high Dep groups were minimal from a clinical standpoint. Depression appeared to contribute to an increased risk of impaired neuropsychological performance across domains, but only in persons not severely compromised by neuropsychological deficits. Overall, the results indicated a small effect of depression on neuropsychological functioning that is likely only detectable in persons whose neuropsychological compromise is relatively minimal.