For the purposes of this paper the term ‘precipitant’ is defined as a new circumstance associated in time with the onset of the addiction. If the precipitant is merely the ‘final staw’ in a long chain of causal circumstances, no particular value can be attached to its identification. If, on the other hand, the precipitant brings into operation the background causal factors leading to addiction, it has important practical and therapeutic implications. It could be expected that this type of precipitant might persist during the addiction and its disappearance might be associated with remission of the addiction.

Among the theories of making rational choices under uncertainty, the one which originated with an eighteenth-century English clergyman, the Reverend Thomas Bayes, and which uses observed evidence to modify prior judgements concerning different possible ‘causes' of the evidence, is logically nearest to the paradigm of clinical diagnosis. A simple illustration of this theorem is the classical Bertrand Box problem (Fry, 1928), and its wider implications for decision making have been discussed by Birnbaum and Maxwell (1960). An example of the use of the theorem in clinical classification has been given by Maxwell (1961).

At the close of the last century there began to spread in the field of psychiatry the idea that every specific pathological agent and every individual toxin produced a picture of psychological disorder that was uniquely characteristic of the causative agent. This idea was extensively developed in the work of Kraepelin (1892) and supplanted the view expressed earlier by Morel, who denied the existence of any specificity in psychological disorders related to their aetiology.

The birth records of 78 subjects born to psychotic parents and 72 subjects born to normal parents were studied.

No significant differences in the rates of pregnancy and birth complications (PBCs) were found between the offspring of psychotic parents and normal control parents. There were no differences between offspring born to psychotic mothers compared to psychotic fathers. Neither the onset of the parent's illness, nor the mother's age at delivery, nor the sex of the offspring seemed to influence the rate of PBCs. The offspring of chronic schizophrenic mothers and manic-depressive fathers had lower PBC rates than the offspring of parents of other diagnostic categories. The parents of these two groups, which were of a limited size, did not differ on any variable of significance, excepting the time of their first psychiatric hospital admission.

The widespread use of group treatment as one of the modern methods of psychotherapy has provided us with an opportunity to study psycho-social phenomena in a fairly uniform social setting.

The early investigators in the field of perceptual isolation were at McGill University, especially Bexton et al. (1954). Since then there have been many subsequent works and papers on the subject. In general, published results of this type of experiment can be divided into two groups. Sometimes marked sequelae to sensory deprivation have been described (Bexton et al., 1954 and Goldberger et al., 1958). Such disturbances included thinking, imagery and time appreciation, together with delusional and hallucinatory phenomena. On the other hand, at Princeton University, Vernon et al. (1956), under very carefully controlled experimental conditions, found virtually no sequelae. A paper published from this hospital (Smith and Lewty, 1959) described a silent room which was designed, constructed and standardized to a mean sound pressure level difference of 80 decibels. (Measurements made at octave intervals from 80-10,000 c./sec.) In this particular room 20 volunteers spent varying periods from 5 hours 50 minutes to 92 hours 20 minutes under conditions of partial and complete sensory deprivation. We used a room so as to mitigate the physical effects of reduced somatic activity and fur gloves were used instead of the more common cardboard cylinders, which after a period of time produce a great deal of skin irritation and indeed abrasions, and introduce a great deal of unnecessary complications into a study of pure sensory deprivation.

The 120th year of our Association's existence is nearing its end and we are approaching the actual 120th anniversary of its foundation. Through the kindness of the Management Committee we are able to meet at its birthplace, Gloucester, and to visit the hospital where it was conceived and brought into existence. At that time known as the Gloucestershire General Lunatic Asylum, and now as Horton Road Hospital, it is one of the oldest buildings continuously in use for the care of the mentally ill.

The relationship between ordinal position of birth and mental illness, and particularly schizophrenia, is a familiar issue to regular readers of this journal. Its significance rests mainly in the fact that on genetic grounds each ordinal position of birth in a sibship is equally vulnerable. Therefore conclusive evidence of a positive relationship between birth order and mental illness, while not excluding the importance of hereditary factors, offers a good indication of the operation of some, possibly early, familial environmental influences.

This November we celebrated the sesquicentennial of the Origin of Species, a landmark in the history of biology. Yet Darwin's chief contribution to psychiatry appears in The Expression of the Emotions in Man and Animals (1872), where he describes ‘the grief muscles’, later identified as a sign of melancholic illness.

Weckowicz (1960), using pictures of common objects with superimposed lines, found that schizophrenics were less able to see the hidden figures than normal subjects and other patients. Unfortimately the task turned out to be too easy; most of the normal subjects and more than a third of the acute schizophrenics obtained the maximum possible score. Such a distribution of scores makes it difficult to carry out further analysis of the results. The aim of the present study was, using a more difficult task to obtain a better distribution, to confirm the lowered capacity of schizophrenics and to relate it to other variables. The task used was the ‘Gottschaldt Figures Test’, published by the University of California Institute of Personality Assessment and Research. This consists of the identification of two simple geometrical figures embedded in complex designs. The score (maximum = 20) is the number of figures correctly identified on two sheets, 2 minutes being allowed for each sheet. To ascertain how this task is ‘normally’ related to certain major personality variables, a group of neurotic patients was used, since they would not be expected to have any special disability on a task of this type.