Summary:After an uneventful 3-year recovery, two patients with severe closed head injury developed an acute onset, organic mood syndrome. Symptomatically, both resembled psychosis associated with temporal lobe epilepsy, although neither patient had overt seizure activity. Treatment is complicated, often requiring a combination of anticonvulsant and antipsychotic medications. Due to the rising survival rates after severe closed head injuries, the recognition and treatment of this type of psychosis will be a significant problem for neuropsychiatry