Five hundred and seventy cases in 252 reports of the delusion of substitution yielded 200 cases with an organic contributor to the occurrence of the delusion. In 79 cases lateralization or localization could be determined, with lesions primarily in the left temporal or right frontal areas. Factors related to ‘feature recognition’, ‘familiarity’ and ‘reduplication’ could be found and are discussed in relation to the neurobehavioral features of the symptom.

A woman with Capgras and de Clérambault's syndromes transmitted persecutory, erotic, and somatic delusions to her son in a folie à deux. Capgras and de Clérambault's syndromes appear together more commonly than is apparent in the literature. Review of these cases shows a strong association with severe affective disorder.

Two patients with erotomania (de Clérambault's syndrome) associated with epilepsy and head trauma are presented. The delusion appeared during periods of mania or hypomania and partially remitted during depression or euthymia. Erotomania may be seen in a wide variety of psychotic conditions, including those that are organically based.

The variants of the Capgras syndrome can be organized into a structure, the delusion of substitution, which itself is embedded in other structures.

Sixty-one inpatients manifesting chronic aphasic syndromes were reviewed. Most aphasic patients with behavioral abnormalities sufficiently severe to require hospitalization had posterior hemispheric lesions and fluent disorders. Thirty-eight (62%) had fluent aphasia, eight (13%) had nonfluent aphasia, and 15 (25%) had anomic, global, or transcortical aphasic syndromes. Delusions were more common among patients with fluent aphasias (58%), whereas depression was the most common psychiatric disorder among patients with anterior lesions (63%). Elation occurred in 12 patients, 11 with posterior lesions and 1 with a nonlocalizing syndrome. Neuropsychiatric disturbances in patients with chronic aphasia syndromes correlate with the type of language disorder and with the location of the associated lesion.