The main reason why I have dared to accept our Council's invitation to deliver this lecture is that it gives me the opportunity to pay tribute to Dr. Blake Marsh with whom I had the privilege of working in the Mental Deficiency Section of the Association.

The study of mental deficiency can be said to be based upon measurement. It is biometrical in a way that the rest of psychiatry is not, because the ultimate criteria for diagnosis of mental defect (or subnormality) are quantitative. Some kind of intelligence measurement or rating is always implied, and even at the lowest level quite often a measurement is actually made. In this lecture I shall only be able to outline my subject by giving examples.

History of term ‘phobia’

The term ‘phobia’ derives from the Greek word ‘phobos’ meaning panic-fear and terror, and from the deity of the same name who provoked fear and panic in one's enemies. Although morbid fears have been described by doctors from Hippocrates onwards, the word phobia has only been used on its own since the beginning of the 19th century, and it gradually gained acceptance during that century in the same sense as today, viz. an intense fear which is out of proportion to the apparent stimulus. Such fear cannot be explained or reasoned away and leads to avoidance of the feared situation where possible.

The treatment of phobic states is one of the most challenging psychiatric problems that face doctors today. Many treatments have been advocated, including intensive psychotherapy (Friedman, 1959), behaviour therapy (Wolpe, 1958; Cooper, Gelder and Marks, 1965) and desensitization under drugs (Yorkston et al., 1968). None of these treatments has proved to be completely effective, and many patients still remain ill and incapacitated for many years. In the series to be reported here, some patients had been ill for as long as 40 years, despite many types of treatment.

Patients are occasionally referred to a psychiatrist with the primary complaint of a cosmetic defect in their appearance, and in a previous communication 45 such patients, dissatisfied with their noses and requesting cosmetic surgery, were studied (Hay, in press).

We have studied 29 school phobic youngsters (14 boys and 15 girls), of mean age 12 years 10 months (S.D. = 14.7 months) shortly before admission to an adolescent psychiatric in-patient unit. The diagnosis was made when there was severe difficulty in attending school, severe emotional upset at the prospect of having to go to school, staying home during school hours with the parents' knowledge and absence of significant anti-social disorders. Information was gathered from the patient and one parent, usually mother. Most youngsters had completely refused to go to school (23) and the remainder went occasionally with great reluctance; this seemed to depend on the attitudes of parents, school and medical agencies. Psychoses, gross physical illness, truancy, and neurotic disturbances other than school phobia resulting in absence from school were excluded. The cases were classified, reliably, into 19 ‘acute’ (11 boys, 8 girk) and 10 ‘chronic’ (3 boys, 7 girls) school phobics. This was done on the criterion of previous severe reluctance to attend school: at least 3 years of trouble-free attendance led to a classification as ‘acute’, the remainder were ‘chronic’. The mean age of the acutes (13 years 1 month) was significantly higher (P<0.001) than that of the chronics (12 years 3 months). In the acutes, the school phobia had been present 5 months (S.D. =3.5 months) on average in the boys, and 1 year 5 months (S.D. = 16.5 months) on average in the girls; which was a significant difference (P<0.02). The mean time between onset of symptoms and complete refusal was 3.5 months [boys-2 months (S.D. = 2 months) girls-6 months (S.D. = 9 months)]. The following features did not show significant differences between the acutes and chronics; social class of the patient's father (the typical social class was 5a on the Hall and Jones Scale of Occupational Prestige for Males), the mean age of mother when the child was bom, the number of only or youngest children in the family, birth complications, the number of severe illnesses, accidents and operations added to separations from mother in the first decade, missing some school without the parents' knowledge, suicidal gestures, the occurrence of symptoms on transfer to secondary school, somatic symptoms, frank mental illness in parents and I.Q. (W.I.S.C. total score); 4 acute cases had symptoms coming on following a bereavement.

Studies of the relation between birth rank and schizophrenia (or any other disorder of adults) have hitherto been based on the assumption that, for a null hypothesis, cases will be randomly distributed among the birth ranks. In other words, if the distribution of cases is found to depart significantly from random (i.e. from equal numbers in each birth rank for each sibship size) then an association between birth rank and the disorder is held to have been demonstrated. However, we have recently shown, both from theoretical considerations (Price and Hare, 1969) and from the study of a large sample of psychiatric patients (Hare and Price, 1969b), that birth-rank distribution may depart very significantly from random because of bias arising from changes in the birth rate of the general population. The amount and direction of this bias will depend both on the changes in family size and on the number of families being started during the period of time when the patients (or any other population sample) and their siblings were born. The amount of bias is thus likely to be different in geographically different populations or in the same population at different periods of time.

Abnormalities in the EEG of schizophrenics were first described by Lemere (1936) who found schizophrenic EEGs had poor alpha waves. Earlier workers were more interested in frequency abnormalities and Davis (1941) found, from study of the frequencies, the more unstable the EEG in schizophrenia the more unstable the behaviour. This concept is well established and has been confirmed by Brazier (1962) and other workers. However, the study of the different frequencies has shed little or no light upon the aetiology of schizophrenia.

In their article published in this Journal in 1965, May and Tuma (1) suggested that only the use of medication made a difference in the outcome with schizophrenics, and that psychotherapy, whether or not combined with medication, made essentially no difference. Their data, however, as in so many psychotherapy projects, referred only to patients treated by inexperienced therapists, namely psychiatric hospital residents under supervision.

In two previous papers (Kay et al., 1969a and b) the results obtained from a material of 104 depressed in-patients were discussed. One hundred of these patients were given the Mauds- ley Personality Inventory (M.P.I.) (Eysenck, 1959) at follow-up (5–7 years after the index admission) with the aim of relating M.P.I. scores at follow-up with the symptomatology of the original illness.

In 1964 Lippold and Redfearn described the mental changes induced by the passage of small positive and negative polarizing Currents through the human brain in volunteer patients. They further reported the clinical effects of polarizing the brain in 29 patients with long standing depression (Redfearn et al., 1964), and they also conducted a controlled trial of polarization in depressive illness (Costain et al., 1964). When the head was positive to the leg, an elevation of mood was said to follow, while the reverse was the case with a negative head electrode. In the uncontrolled trial of long standing depressives, 13 were said to show clinical improvement of the 24 who were considered to be adequately treated. In the controlled trial a significant therapeutic effect was rated by both doctors and nurses. Sheffield and Mowbray (1968), using normal human subjects, failed to validate the mood changes said to follow positive and negative polarization. Lifshitz and Harper (1968) found no appreciable effect of polarization in five chronic male schizophrenic patients studied over 14 weeks. The following study was designed to replicate the double blind trial on depressed patients.

The catecholamine hypothesis of affective disorders proposes that 'some-if not all-depressions are associated with an absolute or relative decrease in catecholamines, particularly norepinephrine, available at central adrenergic receptor sites. Elation, conversely, may be associated with an excess of such amines' (Schildkraut, 1965).

Previous studies from our laboratory (2) indicated that treatment of depressed patients with electric convulsive therapy (ECT) or imipramine was associated with significant decrease of urinary calcium excretion. The studies described in this report were undertaken to find out whether the decreased urinary calcium observed during ECT or treatment with irnipramine was accompanied by changes in the excretion of other urinary metabolites such as phosphate, magnesium, sodium and potassium.

Recently much interest has been shown in the screening of populations for the presence of disease, either latent or overt (Wilson and Junger, 1968). In psychiatric practice the importance has been recorded of screening patients for the presence of avitaminosis B12 as a possible cause of psychiatric abnormality (Henderson et al 1966). Several methods of estimating serum vitamin-B12 levels have been evaluated, but the microbiological assay remains the most suitable method for use in a routine laboratory.

Favourable results have been reported from the use of lysergide in a wide variety of psychiatric conditions, but controlled studies (2, 3, 4) have not confirmed the existence of a therapeutic effect. In this experiment, alcoholics and neurotics who had been referred by Saskatoon psychiatrists for LSD treatment were allocated at random to Treatment and Control groups after undergoing a series of psychological tests. The members of the Treatment group were offered up to five LSD experiences at intervals of two weeks, whereas those in the Control group were informed that this type of therapy would be made available to them after a twelve-month waiting period. Accounts of the LSD experiences were sent to the referring psychiatrists, who were expected to continue to provide standard treatment to the members of both groups.

In recent years the recognition of autoimmune processes has led to important advances in our understanding of certain diseases of hitherto uncertain causation (Mackay and Burnet, 1963). In psychiatry, schizophrenia has been the main focus of studies of auto-immunity, with Heath and Krupp (1967) reporting positive results of tests for antibodies to brain cell nuclei and Whittingham et al. (1968) reporting negative results. Studies have been described (McAlpine et al., 1965) in which antibodies were detected to whole brain homogen- ates, mostly by complement-fixation, in various disease states that included multiple sclerosis. Wilkinson and Zeromski (1965) found, by immunofluorescence, serum antibodies to cytoplasm of neurones in four of eight patients with carcinomatous neuropathy.