Individuals affected by mental retardation are a clinically and aetiologically heterogeneous group. This heterogeneity is particularly highlighted when we consider the genetics of mental retardation. Recent advances in molecular genetic techniques have enabled us to understand more about the molecular basis of several genetic syndromes associated with mental retardation. In contrast, where there is no discrete cause, the interplay of genetic and environmental influences remains poorly understood.

Trifluoperazine (Stelazine) is a phenothiazine derivative and is 2-trifluoromethyl-10-(3′ 1″-methyl piperazinyl-4″-propyl) phenothiazine dihydrochloride. It is related to prochlorperazine, and in fact differs only in having a trifluoromethyl group in place of the latter's chlorine atom in position 2 of the nucleus. However, in laboratory studies, tests based on the inhibition of conditioned responses have indicated that this compound was 5 times as effective as prochlorperazine and 10 times as potent as chlorpromazine on a weight for weight basis.

Since 1922, when Kläsi's work on prolonged narcosis with somnifen—a mixture of barbitals—appeared, this form of treatment has become an integral part of the armamentarium of psychiatry. Patients suffering from various psychoses were subjected for a longer or shorter period to intoxication by a hypnotic, with or without the production of a prolonged sleep. Successes—sometimes very great successes—were claimed for this treatment. The number of publications on this subject is so large and the successes described therein so numerous, that the clinical worker is in duty bound to form an independent opinion regarding this method. The question is whether there is anything in this therapeutic method which psychiatry should retain, what that something is, and whether or not we can improve its system of procedure. Too great an enthusiasm is equally dangerous here, as is underrating the method because of a single unfortunate experience during or following the treatment.

The personality of people who develop a depressive illness has been the subject of much controversy. Most of what has been written is based on clinical observations made during the illness and on inferences drawn from symptoms and there are few investigations based on studies of patients when they were not ill. The present investigation was carried out on women after they had recovered from a depressive illness.

Temporal lobe and limbic structures may be abnormal in bipolar disorder. T2-weighted magnetic resonance imaging (MRI) scans frequently show deep white matter lesions. MRI was performed on 50 young (19–39 years) euthymic patients with bipolar disorder and 26 controls. Mean temporal lobe volumes were reduced in patients (right, 9.42 cm3; left, 6.33 cm3) but this could not be ascribed to a specific structure. Deep white matter lesions were present in 5 patients but no controls raising questions of their aetiological significance.

Psychotropic drugs reduce morbidity and mortality related to maternal mental illness but may also cause harm to the foetus, the nature and magnitude of which is not completely understood. Up-to-date information should be shared as fully as possible with the pregnant woman and a treatment plan agreed jointly.

Although there have been many attempts to discover in the body fluids, chemical peculiarities characteristic of schizophrenic illness, the outcome of most of these investigations has been inconclusive (see for example Altschule, 1953; Kety, 1959). Little attention has been paid, however, to purine metabolism until the recent studies of Kishimoto (1958) who reported peculiarities in the absorption spectra of body fluids in schizophrenia which he attributed to abnormalities in the conversion of adenine through hypoxanthine and xanthine to uric acid. These findings appeared to be supported by evidence which included the determination of urinary xanthine by a xanthine oxidase method based on that of Williams (1950).

In choosing the subject for this Lecture commemorating the august personality of Henry Maudsley, I did not intend to be exhaustive and I had in mind two things. I would like to discuss how the study of intellectual defects and their objective measurement may contribute to the knowledge of what Maudsley (1895) called the pathology of mind. Also, I would like to draw attention to the way in which clinical work in mental deficiency may help to explain some of the causes of mental illnesses. The first topic is psychological, the second is biological.

‘New chronic inpatients' (patients aged 18–64 years in hospital more than one but less than six years) were followed-up two years after identification in the catchment areas of 14 psychiatric hospitals, serving 56% of the Scottish population. Nine per cent had died, 71% remained in-patients, and 20% had been discharged; 40% of those discharged had no contact with after-care services, and 37% of those remaining in hospital did not need in-patient care. Discharged patients were younger, had been in hospital a shorter time, and less often had organic brain disease. Only 13% of patients who, when first identified, had been rated at a low functioning level had been discharged; 64% of those remaining in-patients at follow up had such a rating.

Seven units providing psychiatric day care to residents of an inner-city area were surveyed. The extent to which the clinical and special problems of attenders were adequately managed by the services was measured using a ‘needs-assessment’ technique. Units differed in the proportion of clinical and social problems that were rated as ‘unmet needs', although the extent of ‘unmet need’ was not clearly related to the morbidity of attenders at a unit or the available staffing.

Asphyxia as a means of heightening sexual pleasure unfortunately comes to notice more often in the coroner's court than in the psychiatrist's consulting room. The victims are usually adolescent men who strangle or hang themselves while masturbating; transvestism is frequently associated with this behaviour (Simpson, 1979; Friedmann & Faguet, 1982; Mason, 1983). Few such people ask for help, and behavioural treatment in such a case has not been previously described.

The term ‘therapeutic community’ has been increasingly employed in recent years. The W.H.O. Report (1953) used it to describe a general approach of Freedom, Activity and Responsibility—a humane, liberal approach marked by full occupation, open doors, active rehabilitation programmes and increased community involvement—repeating and developing many of the features of the ‘moral treatment’ of the early nineteenth-century (Rees, 1957). This has now been widely adopted in Britain, U.S.A. and in Western Europe.

Little has been published about psychiatric out-patient work, and even less about the relationship between in-patient and out-patient psychiatric facilities in service requirements for a given population. The reasons for this are partly general to the whole field of medicine —a preoccupation with severe illness and the hospital bed to which it inevitably leads— and partly particular to psychiatry. The growth of out-patient psychiatric work is relatively recent, and its existence outside teaching hospitals is largely a National Health Service development. With in-patients concentrated in large mental hospitals serving an extensive area, the psychiatrist's connection with any individual general hospital was necessarily limited and the out-patients a small and peripheral part of his work.

During the investigation of somatosensory evoked cortical potentials arising from a complex vibro-tactile stimulus to the forefingers, an abnormal lack of lateralisation of response was found in 10 out of 21 schizophrenic patients. Eight patients with severe affective illness all had the expected degree of lateralisation of cortical potentials, as did 12 out of 15 normals. Three normals and 3 schizophrenic patients had a loss of lateralisation of the evoked response on stimulation of one hand but a normal lateralisation on stimulation of the other. The considerable technical problems of this and related techniques are discussed, but it is suggested that further exploration of this technique is justified. At this stage, no conclusion can be drawn about the cause of the abnormalities.