The appearance of chronic psychotic states, clinically closely resembling schizophrenia, in epileptic patients has been recorded from time to time by many authors. The more significant of these papers are here reviewed. Most recently Pond has associated chronic paranoid psychoses resembling schizophrenia with temporal lobe epilepsy.

Patients of this type have been collected, as systematically as circumstances permitted, at the National Hospital, Queen Square, and at the Maudsley Hospital; 69 such patients were found, and have been investigated.

1. The question is examined whether the purely coincidental combination of epilepsy and schizophrenia, each of them relatively common disorders, would be sufficiently frequent to make such a collection possible. It is concluded that this is not so, and that in the bulk of cases the combination cannot be randomly determined.

2. As the appearance of a schizophrenic-like psychosis in an epileptic might be aided by a schizoid predisposition, the past personalities of these patients were examined. It was concluded that the premorbid personality was of normal type, but that when the onset of epilepsy was early, epileptic personality changes could be found in the prepsychotic personality. There was no evidence of schizoid traits in excess.

3. The mean age of onset of the psychosis was 29.8 years, after the epilepsy had lasted for a mean duration of 14.1 years. There was a significant correlation coefficient between the ages of onset of epilepsy and of schizophrenia of +0.6, indicating that the duration of the epilepsy was likely to be one of the causative factors. There was no close relationship between the frequency of fits and the onset of psychosis; but in some instances there was a suggestion of an inverse relationship, e.g. psychotic symptoms first appearing when the fit frequency was falling.

4. The modes of onset of the psychosis could be classified into acute, episodic, subacute and insidious. The last of these was the commonest (29 patients), with onset of an episodic kind the next most frequent (20 patients). The course of the psychosis was similarly classified into one with tendency to improve, a fluctuating course, and a course tending to chronicity. Of these the last was the most frequent (31 patients).

5. A phenomenological analysis of the schizophrenic symptoms shown by our patients showed delusion-formation of a typically schizophrenic kind in all but two of the patients. Typically schizophrenic hallucinatory experiences in clear consciousness occurred in 52 patients, auditory hallucinations predominating. Affective disturbances of a great variety of kinds were experienced by these patients, depressions and ecstasies being not infrequent. The most typically schizophrenic affective symptom of flatness of emotional response was observed, at least to some degree, in 28 patients. Disturbances of volition and catatonic phenomena were shown by 40 patients. The commonest form of thought disorder shown was of a type compatible with organic states, e.g. deficiency of conceptual thinking, circumstantiality, etc. Thought disorder of a specifically schizophrenic kind was shown to some degree by 31 patients. It is concluded that there is not one of the cardinal symptoms of schizophrenia which has not been exhibited at some time by these patients. It would not be possible to diagnose these patients, on psychological symptomatology alone, as suffering from anything other than a schizophrenic psychosis; the recognition of the psychosis as essentially epileptic in origin requires consideration of all the available information.