Leucocyte migration inhibition test in post-antirabies vaccinal encephalitis (a preliminary communication).
Depersonalization is a ubiquitious and complex symptom. It can occur in functional and organic disorders but is rare as a pure syndrome. Its incidence in acute psychiatric patients is estimated to be around 80%1 but is not commonly expressed without specific inquiry., 
The literature on this subject is scanty and mostly interpretive in nature. The interest in depersonalization as a phenomenon has been recent. Inspite of religious and mystical influences prevalent in India, only one study of depersonalization in Indian psychiatric population has been reported.
The present study was carried out to study the phenomenon of depersonalization in various psychiatric illnesses.
All co-operative patients attending the out-patient services of the Department of Psychiatry, K.E.M. Hospital, Bombay were screened for the symptom of depersonalization over a period of two months.
They were enquired for the feeling of unreality about themselves and about the world around them. Those patients who answered the above query affirmatively were administered Dixon's Depersonalization Questionnaire (DPQ). Those patients who answered positively for three or more items of the questionnaire were included in the study. Patients who could not communicate their personal experience clearly and were unto-operative were not screened for the study.
A structured proforma, including details of depersonalization experience was filled in with the help of the patients and their relatives. Diagnosis was established by two senior psychiatrists independently. Psychological tests and other investigations were carried out when required.
All patients were also assessed on Depression Status Inventory (DSI) and Taylor's Manifest Anxiety Scale (TMAS). Their personality traits were assessed by Hysteria-Obsessional Questionnaire (HOQ) and Eysenck's Personality Inventory (EPI). Their level of intelligence was measured by standard progressive matrices.
A control group matched for age, sex and diagnosis was administered the same psychological tests and rating scales.
The data was subjected to statistical analysis.
Thirty two patients with the symptom of depersonalization were studied. Their age and sex distribution is presented in [Table 1].
[Table 2] shows the diagnostic distribution of the patients having depersonalization.
The proportion of schizophrenics in the index group (0.65) was significantly greater (p < 0.05) than that in the total population (0.43) when compared by the large sample binomial test.
The total duration of symptoms of depersonalization ranged from four days to eight years. In seven patients, the depersonalization was a continuous experience and all these patients were diagnosed to be suffering from schizophrenia. In 14 patients the experience of depersonalization was episodic lasting from two minutes to two hours, mean duration being 24.41 minutes. No diagnostic group predominated in these patients. The remaining one patient had intermittent episodes of depersonalization lastig for 6 days followed by depersonalization-free period of about 10 days.
The frequency of attacks of depersonalization ranged from four to five per day to once in seven months. The median distribution showed that half of the patients had frequency of less than 15 times a month.
A variety of factors precipitated and/or aggravated depersonalization in 18 patients. [Table 3].
Thirty patients found their depersonalization experience as unpleasant and the other two had a neutral attitude towards it. None of the patients related depersonalization feelings with religious experience, nor did they find it as pleasant.
Nine patients had experienced depersonalization prior to the present episode of illness. Out of these, four patients had these attacks in the background of a psychiatric illness.
Seven patients reported daily consumption of alcohol in moderate quantify. Two patients had their depersonalization experience following intake of alcohol. In one patient the onset of depersonalization was precipitated following consumption of cannabis.
Eighteen patients from the index group had symptoms of phobia. Binomial test showed no significant difference in the incidence of phobia between the males and females in each of the groups. There was no difference in the proportion of phobia between the two groups.
Analysis of the scores of the TMAS [Table 4] showed that the index group had significantly higher amount of manifest anxiety as compared to the control group (p < 0.05).
Analysis of the scores of Depression Status Inventory showed that the average score and the proportion of patients having total scores of more than 50 was significantly higher in the index group as compared to the control group.
Analysis of the scores of HOQ and extraversion score of EPI and of percentile intellegence did not show any significant difference between the index and control groups.
Detection of depersonalization is dependent upon the method of enquiry. Direct questioning assists the person to verbalise his strange depersonalization experience which he finds difficult to express otherwise. The present study showed that on direct questioning 32 patients reported the symptom of depersonalization amongst a total of 288 co-operative patients (7.6%). In another Indian study by Teja et al, only 0.76%patients had depersonalization on retrospective analysis of 6450 patients.
The difficulty in reporting this experience was not related to any religious or mystical quality as proposed by Teja et ale but was probably due to inadequate vocabulary or fear of being interpreted as a sign of insanity. This experience does exist in this culture and can be studied as any other psychiatric phenomenon.
It is a common experience in the population attending this hospital that medical help is resorted to only when the underlying illness disturbs the earning or functioning capacity. Majority of the patients found depersonalization experience unpleasant. Inspite of this they reported to hospital only when their functioning was affected. The population attending this hospital came from a low socio-economical strata. The relatively higher incidence of underlying schizophenia and absence of primary depersonalization syndrome may also be related to the disability produced.
Increased symptoms of anxiety and depression in the patients suffering from depersonalization may be related to the unpleasant and strange characteristic of experience.
The period of depersonalization did not correlate with total duration of illness. Continuous depersonalization experience occurred only in schizophrenia and may have a diagnostic bearing.
The authors thank Dr. C. K. Deshpande, Dean, K.E.M. Hospital and Seth G.S. Medical College for permission to publish this report.
Grateful acknowledgement is made to Dr. D. R. Doongaji for helpful guidance.