Prevalence of apathy following head injury.

Although several studies have examined the demographics of mood disorders and personality changes following closed head injury (CHI), there are no studies that address the prevalence of apathy after CHI. Utilizing standardized evaluation tools, this study examines the prevalence of apathy in 83 consecutive patients seen in a neuropsychiatric clinic. A total of 10.84% had apathy without depression while an equal number were depressed without apathy; another 60% of patients exhibited both apathy and depression. Younger patients were more likely to be apathetic than older patients who were more likely to be depressed and apathetic. Patients with severe injury were more likely to exhibit apathy alone. Family members rated the patients higher on apathy scale. These findings suggest that apathy is a frequent symptom after head injury and may occur either alone or in association with depression.