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By: R.J.M Collis

(This paper about psychiatric treatment of the poor in Yoruba villages in northwestern Nigeria, was published by the American Philosophical Society in 1966 barely six years after Nigeria gained independence from England. Nevertheless, Dr. Collins’ observations are just as valid fifty years later as our organization works to build a Western style hospital – The Catholic League Medical and Mental Hospital –for rural communities in and around Okoti, Odekpe, Anambra State in southeastern Nigeria.)

NOTE: The text that follows here is a condensed version of Dr. Collis’ much longer and highly detailed clinical report. To read a PDF file of the complete report, CLICK HERE.


In February, 1961, the Cornell-Aro Mental Health Research project took to the field. It was de­ signed as a pilot epidemiological study involving the examination of a sample of patients in Aro Hospital, and samples of the residents of fourteen nearby villages and of the town of Abeokuta, in order to ascertain the prevalence and types of psychiatric symptoms and to assess the influence of selected cultural factors on them. Questionnaires for gathering psychiatric and sociocultural data had been developed and the psychiatric interviews were carried out by six psychiatrists. The interviews recorded were jointly evaluated by two psychiatrists and the respondents divided into four categories, the first being “cases,” the fourth “normals.”
During the period February to May, while the field work was being done, the present writer acted as Medical Assistant and ran clinics in the villages to estimate the general standard of health and maintain the good will of the inhabitants. The observation that there was a great deal of physical disease, though little grave illness in the villages, combined with the availability of the untreated psychiatric “cases” suggested an investigation to try to define a little more clearly the relationship of this physical ill health to psychiatric disorder.
The part played by physical diseases, trauma and dietary deficiencies in African psychiatry is known to be a big one. Some conditions such as trypanosomiasis, syphilis, cerebral malaria, cerebral cysticercosis, meningitis, encephalitis, kwashiorkor, pellagra, and psychosis associated with acute bacterial infections and influenza produce effects which are specific and determinable.
Far less clear, however, is the role played by some of the same agents, acting less malignantly and usually in combination, which results in a continual state of lowered physical health. In this category the following conditions are important in Nigeria: malaria parisitemia, schistosomiasis, hook-worm infestation, amoebiasis, calorie deficiency, protein deficiency or vitamin deficiency.
Smartt referring to such conditions wrote:
Because of the prevalence of malnutrition and infection, many Africans probably live on the verge of mental break­ down and a minor illness may be sufficient to produce psychotic symptoms.
This would seem to be too sweeping a statement, for, if it were true, a high incidence of psychosis would be expected, which is not found. In our experience these factors act in a much less clearly defined manner, and Carothers would seem to be nearer the truth when he noted:
… others simply produce a background of ill health which must predispose to mental breakdown or aggravate it later. Of these more insidious infections, the most important are malaria, bilharziasis, ankylostomiasis and amoebiasis, but the role they play is usually obscure.
Various other workers in different parts of Africa have made similar observations.
The reason for the obscurity of the part played by such physical depletion becomes clearer when we glance at some of the complicating factors inherent in Yoruba culture, and in many “simple” cultures. Among these are the Yoruba’s inability to distinguish at all clearly between the psyche and the soma; his marked degree of suggestibility; his tendency to add a strong functional overlay to physical illness; his habit of expressing anxiety and depression through somatic symptoms, and his ill-balanced and often inadequate diet that requires only a minor degree of disability of functional origin to cause a physical depletion.
Thus, we might legitimately expect to meet a number of functional illnesses associated with a poor state of health. The problem is: how can one determine what part these physical factors have played in the etiology and course of the functional conditions? It seemed that the most practical method open to us would be to compare the results of treatment aimed at resolving the functional symptoms with that of treatment directed at achieving good physical health, using placebos for “control.” Thus, if an illness was resolved by purely physical treatment, its origin could be presumed to be predominantly physical and the functional element to be secondary. Conversely, if it were resolved by psychiatric treatment its origin would be judged largely psychological, the poor physical condition being either habitual or secondary. This was, therefore, envisaged as the key test in our study. The term “physical treatment” in this article refers to treatment aimed at curing bodily disease or depletion and promoting good physical health. It does not include the use of psychotropic drugs or electro-convulsive therapy.
The research design was to take a sample of the people from the epidemiological survey who showed functional illnesses not associated with epilepsy, encephalitis, etc., to investigate them as fully as possible from both psychiatric and physical points of view; and to compare their physical status with that of a mentally healthy control group. Then we would divide the sub­ jects into treatment groups and compare the results of treatment by the contrasting methods described.
It was realized that there were too many obstacles in our path for any conclusive findings to be achieved. For instance the course of a mental illness may be altered by myriad factors, within the patient and in his environment; it is so susceptible to unforeseen changes of fortune that a change cannot safely be attributed to a therapeutic regime unless it is frequently and regularly produced or comes promptly on the tail of treatment.
To minimize sources of error it is necessary for such a trial to be controlled as rigorously as possible. Sub­jects to be used as controls ( i.e., those receiving placebos in our study) should be closely comparable to those who are treated. But the matching of psychiatric groups for this purpose is very complex and requires a large pool of cases to draw from. They should be alike at least in the distribution of sex, age, intelligence, duration of illness, form and severity of illness and previous treatment; alike also in psychodynamic factors and physical state if possible.
It was clear at the outset that these ideal requirements could not be fulfilled; nevertheless, the simplified experimental design seemed practical and scientific enough to allow valuable data to be collected. It could he hoped that some interesting, perhaps even important, observations could be made which might be of aid to the better equipped follower of this trail.



Nigeria lies roughly between latitudes 4° and 14° north of the Equator. It may be divided into two natural regions, equatorial forest and tropical grass land. Abeokuta province, where this study was made, lies in the deciduous forest belt where these two types of vegetation blend one into the other. Here the forest is less dense, and a large proportion of the trees shed their leaves during the hot, dry season.
The Yoruba, some six million in number, occupy most of southwestern Nigeria, extending from the Guinea Coast to the Niger Delta, and bounded on the west by the Republic of Dahomey (see map 1). This area extends over two hundred miles inland to Lokoja where the rivers Niger and Benne join. ·westernization is carrying more people into industry and trade, but the Yoruba still form a predominantly agricultural community. The people involved in this study live in Abeokuta town and in twelve nearby villages (see map).


In two of the fourteen villages used in the Aro-Cornell project no “case” could be found who was willing to cooperate in this study. Abeokuta town has a popula­tion of about 80,000 and is among the larger and more traditional of the Yoruba provincial towns. The villages in which the bulk (77 per cent) of the respondents lived were chosen for epidemiological reasons to show a variety of such features as size ( 37 to 2,130 inhabitants) , level of prosperity, closeness to main roads and urban centers, and traditional or changing way of life. It is important to emphasize that this study involved the traditional and unwesternized Yoruba, and descriptive passages are confined to this section of the population. There is a rapidly expanding community who are better off in many material ways and much more like Europeans in thought and habit.

MAP. The Yoruba villages lie in close proximity to a large river (Ogun river).  Egbo land, in Anambra State, also borders a river (Niger river) which today provides the same conditions for the poor of Egbo land  as those faced by the poor of Yoruba land studied by Dr.Collis in 1966.


Owing to the difficulty of clearing the land, and the speed at which plants grow, the farms of the area in which this investigation was carried out are very small. Two or three acres is all the land the labors of one family can manage, but from this they raise crops of considerable variety, often one crop following another on the same plot of land according to the season. The main crops grown in this area are yams, cassava (tapioca), and maize. Smaller amounts of plantains, beans, green vegetables, chillies, kola-nuts, groundnuts, and bananas are also raised. Some of the villages grow a little rice also, and a few of them have small cocoa plantations. Citrus fruits, coconuts, pawpaws, and palm nuts are mostly collected from the bush. Little stock is kept; a few chickens and two or three goats or sheep make up the total livestock for a family.
The diet of the villagers consists mainly of yam, cassava, and maize. Meat is scarce and is seldom eaten except at religious festivals or celebrations. The goats are not milked, and eggs are very rarely eaten. Little fruit or green vegetables are eaten though they are plentiful.
In a recent survey of five Yoruba farming villages very similar to those in our study, it was found that over a period of a year, the percentage of families having less than average minimum requirements of calories varied from sixty in the best village to ninety-five in the worst (19). It was also shown that no one family in any of the villages achieved average protein requirements using the FAO/WHO (1953) scale.
Thus from a nutritional standpoint, the Yoruba is seen to be not at all well off. Many other African peoples also have unsatisfactory diets. A similar study of the Bemba tribe in Rhodesia revealed a diet with a calorific value just over half that of the white Rhodesian which was inadequate by American standards (72).


When one contemplates the number of diseases to which people in Nigeria are exposed, one is continually amazed that there are so many apparently healthy people to be seen. Survival of the fittest is the rule, however, for probably more than fifty per cent of those born do not live to see twenty years, death’s toll being heaviest in the first few years.
Exposure to a variety of parasites is almost continual. Malaria, hookworm infestation, ascariasis, amoebiasis, schistosomiasis, and filariasis are often all present in the carrier state in a single person at the same time. The actual diseases caused by some of these parasites seem to occur particularly when greater demands than usual are placed on the body, as in pregnancy, lactation, prolonged physical labor, or when nutrition is lowered.

Other common tropical or predominantly tropical conditions found in adults are: bacilliary dysentery, gastroenteritis, tetanus, endomyocardial fibrosis, malnutrition, yaws, dracontiasis, tropical pyomyositis, tropical ulcer, myiasis, cheloid, and ainhum. Less often one sees a case of leprosy, pellagra, trypanosomiasis, sickle cell disease, or lymphogranuloma inguinale. Outbreaks of smallpox also occur every few years.
Almost all the diseases of temperate climates are also found in Nigeria, though their pattern is sometimes altered. Finally, there are a number of rarer but potentially lethal hazards such as snake bite, scorpion sting, and poisoning by one’s enemy. To complete the picture, it is necessary to mention that modern medical facilities are still rudimentary, and ignorance of the most elementary rules of hygiene is widespread.

The traditional Yoruba is not neglectful of disease and deals with it conscientiously if rarely curatively. When he is struck by illness or misfortune he will ascribe his troubles to supernatural agents unless the cause is strikingly obvious as in the case of fever or the common cold. In fact, he is forced to think this way because of the limitations of the explanation of phenomena that the tribal culture offers him. Disease, death. or any catastrophe is thus usually believed to be due to one of the following: “bad medicine,” witchcraft, a curse, bad spirits, not paying proper attention to one’s deity. Or “going against one’s destiny.”
However, in dealing with psychoneurotic reactions among the traditional Yoruba, the native doctor-priest would seem to be just as successful as his Western­ trained counterpart, maybe more so. He commonly involves his patient in an active therapeutic regime which often requires the patient to become a member of a cult group of the native religion. This is an arduous. demanding and long-drawn-out procedure and would seem to complete the process of projection which the patient has usually initiated himself. In many cases this therapy ultimately provides the patient with a new modus vivendi and a new and more remunerative source of income, because he may well go on to become a priest
of the particular deity. The author has seen many of these Yoruba “psychiatrists” at work and has frequently been very impressed by their wisdom and insight and has borrowed a number of techniques from them which have proved of great value in treating the unwesternized Yoruba.
Prophylaxis and treatment of disease are thus of a predominantly magical type. Rings and amulets are worn for protection against witchcraft and disease and a combination of ritual, sacrifice, and magic potions is used in treatment. Some herbs containing potentially therapeutic pharmaceutical substances, e.g., rauwolfia, are sometimes used in these potions, but as they are commonly mixed with a variety of toxic substances they rarely do much good.
The precise effect on the African of a poor diet, of playing host to so many parasites and of frequent attacks of disease, is subject to much discussion and investigation at the present time. It is possible that the whole answer will not be revealed until all these disease factors have been removed. Routine post mortem studies almost invariably reveal extensive pathology in the liver and spleen and often in the kidney and pancreas. The slowness of movement, easy fatigability and poor powers of observation so often noted in the African probably represent an essential energy conservation mechanism at work.

During the epidemiological survey, the writer with his mobile clinic treated over four thousand patients, half of whom were children. It was not possible to correlate the number of sick people precisely with the population of a village, for when word got around that free medicine was available, many sick people came from neighboring villages. In all but two of the villages many sick people were seen, and almost all of the tropical conditions mentioned were recognized in one place or another. The ten most common complaints in order of frequency were: intestinal worms, malarial fever, skin rashes (non-septic), abdominal pain, weakness, cough, joint pains, septic rashes, tropical ulcer. and foot sores. Despite their proximity to the town (not over five miles or so) only three of the fourteen villages had previously seen any form of health worker. These three were visited four times a year by a health inspector whose knowledge of medicine is less than that of a junior nurse. In consequence the villages knew very little of Western medicine. Hospitals were viewed as places where one died, and many seriously ill people refused to be admitted.


(NOTE: The following description of the testing method has been edited for brevity. Complete details, with the exact treatments and laboratory controls used may be accessed by reading the actual report article in PDF format, by CLICKING HERE. Please recognize the intellectual property rights of the publisher and the author as indicated on the original document.)

Stage 1: Comparison of the physical findings and laboratory investigations of a group of “cases” with those of a control group of “normals.”
The full sample of psychiatric “cases” was taken from the Cornell-Aro study. From it were removed Aro Hospital patients, those with a history of epilepsy, those whose condition had an obvious organic basis. e.g., post-encephalitics. The remainder, sixty-five in number, formed the group for investigation. As many members of this new group as would cooperate were then investigated thoroughly from a psychiatric point of view. A physical examination was performed on each of them and the following laboratory investigations were made.

Stage 2: Comparison of the results obtained using contrasting methods of treatment.
Phase A: Division of the “cases” into three groups, each receiving different forms of treatment for three months.
Phase B: A different type of treatment was given for eight weeks to those who failed to improve in Phase A, assuring thereby that some from all groups would have had physical treatment.

Stage 3: Assessment of the rate of relapse.
Three months after the cessation of all treatment, the patients who were “improved” or “greatly improved” were interviewed again and the rate of relapse recorded, using the same criteria. Any degree of deterioration in a patient’s mental state was taken to constitute a relapse.

There were many foreseeable difficulties and sources of error inherent in such a plan. However, it seemed that the information obtained would be most interesting and might lead to better formulation of hypotheses for future workers in this field.


Because of the wide variety of medicaments dispensed, the “double blind” technique could not be used. Thus, the author was in a position to discover what he set out to find. This risk was allayed slightly by the divergent and inconclusive views expressed in the literature which were not conducive to building up preconceived ideas.
The groups which were to undergo treatment might not have been at all well balanced in psychopathological material. This risk was obviated to a large extent by a form of preselection. Few overt psychotics were met with in the villages or the town during the Cornell-Aro study because they had already been brought to the hospitals of native therapists. Hysterical conversion syndromes were almost absent for the same reason. Obsessional neurosis is very rare, and none was seen. And, as previously mentioned, the author eliminated those of clear-cut organic origin. Thus, the bulk of the “cases” were a heterogeneous group of psycho­neurotic states.
The administration of psychiatric drugs is only a part of psychiatric treatment though it is necessarily a large part in Kigeria. Hence a lower improvement rate and a higher relapse were to be expected in the absence of psychotherapy.
Errors due to placebo reaction had to be considered especially as we were dealing with Africans who are renowned for displaying a high incidence of this phenomenon. It was felt that an initial treatment period of three months would be sufficient to allow patients displaying such reactions initially to relapse to their previous state. This proved to be true, for many of the group receiving placebos showed improvement between two and five weeks after commencement of treatment, after which all but one relapsed to their previous condition.


The necessity of using translators was a further drawback. The dangers of being given the answers you want, of losing the meaning in translation, of having no rapport with the patient, of the effect of fatigue on the three participants, were present. These were reduced as far as possible by the following means: three translators were alternated; one was an intelligent psychiatrically trained nursing superintendent, another an asylum warder whose translation was very literal or “pidgin,” and the third a young girl receptionist who was fluent in both languages but knew nothing of psychiatry. All three had been well instructed in not feeding answers and other details. It was rarely possible to do more than three interviews in one day owing to the time taken to get to a village. There were usually quite long intervals between each interview while the next respondent was being found, so fatigue due to monotony did not occur.
The difficulty of covering such a wide area, and of even getting into some of the more remote villages during the rains, while carrying on routine hospital work, was recognized but proved surmountable.


It was thought that some might fail to take their medicine or take it incorrectly. Surprisingly, all but one of those treated took their medicine correctly. We spent a lot of time checking on this for some of the medicines were potentially lethal.
There was the foreseen error that some of the people rated as “cases” on the basis of one interview during the Cornell-Aro study would on a more extended examination prove to be well, and that some of the ” normals ” would prove to be “cases.” The expected error of the Cornell-Aro Research method is 15 per cent. Twelve of the fifty-three “cases” interviewed showed no psychiatric disorder though five of these gave evidence of having had psychiatric symptoms at the time of the Cornell-Aro study. All of the “normals” were mentally healthy.
That a few might not cooperate at any stage was thought of, but the friendly reception we received in most of the villages during the Cornell-Aro study made one think that this would not be a major factor. In fact, it proved to be a serious obstacle.

In the first place, the division of the selected “cases” into three groups x, y, and z was done randomly, and the control group of normals was also a random sample. The work was started and then the unexpected occurred. The chief of the first village was openly hostile and refused to answer questions or even to let us into the village. The reason for his animosity remained obscure but was probably related to a village feud which had been going on for some time. We received a better reception in the next few villages, but nevertheless some of the respondents made it clear that they did not desire treatment, others that they would not come to the laboratory because of fear of hospitals in general. Some ran away into the bush when we entered the village and remained out of sight during the whole period of study. Two had moved to other areas.


To wait until all those “cases” willing to cooperate were unearthed and then draw random samples again was not possible, for we knew it would take over two months to get around them all and if no treatment were given during that time many more would withdraw their cooperation. So the procedure adopted was to mark the first cooperator who proved to have a psychiatric illness x, the next y, the next z, and so on.
The original sample had sixty-five “cases” but it was only possible to take histories from fifty-three, and eight of these fifty-three refused either laboratory investigations or treatment. Twelve others mentioned above had no psychiatric disorder. Thus our “cases” were reduced to thirty-three. These thirty-three patients and the twenty “normals” were found to be scattered over twelve of the villages and Abeokuta town. They were investigated in the manner described.
A final point that had to be considered was that some people might move to other areas and that some might die during the period of study. One of the “cases” died within a month of commencing treatment and another died after the completion of the three-month period of treatment.
The control group were cooperative about history taking, but five refused either treatment or laboratory tests. Further, one had moved to another area and one proved to be a close relative of a member of the hospital staff and was considered unsuitable. So, again the random selection was broken. We made up the seven that we had lost by interviewing other “normals” in seven of the villages in which we had “cases” but from which we had not drawn more than one “normal” so far.

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