Recent clinical and epidemiological trends in parasuicide in Edinburgh and Oxford: a tale of two cities

SynopsisThis is a report of clinical and epidemiological trends in parasuicide in Edinburgh and Oxford over the period 1976 to 1984. Rates of parasuicide declined in both cities, but more markedly among women than men. Male rates tended to be higher in Edinburgh and female rates higher in Oxford. Age-specific rates were similar for the two cities in 1983–84, with peak rates for females among 15–19 year olds and those for males among 20–24 year olds in Edinburgh and 25–34 year olds in Oxford. Parasuicide incidence was higher in lower social class groups and among the unemployed in both cities. During the study period there was a massive decline in barbiturate overdoses, a more modest decline in minor tranquillizer overdoses but, in Oxford, a marked increase in self-poisoning with paracetamol. By the end of the study period the proportion of patients receiving a diagnosis of drug addiction had doubled in Edinburgh, although it had remained fairly constant in Oxford. There were differences in patterns of aftercare offered to patients in the two cities; these almost certainly reflect differing clinical policies.

Pavlovian Counterconditioning is Unchanged by Chlordiazepoxide or by Septal Lesions

Two experiments were performed to test whether the minor tranquillizer chlordiaz-epoxide or septal lesions could interfere with Pavlovian counterconditioning. Rats were first trained to bar-press for food on a random interval schedule on which was superimposed the presentation of a light which predicted delivery of a shock. This training continued until all animals were showing stable suppression of responding to the light. Separate groups were then presented, while the manipulandum was retracted from the box, with either a shock paired with the delivery of food or shock and food delivery in a random relationship with one another. This type of intrusion period alternated with the presentation of the light and shock. Pavlovian counterconditioning developed, as shown by progressively less response suppression in the paired groups compared to the random groups. This Pavlovian counterconditioning was in no way reduced by either chlordiazepoxide (5 mg/kg) or by medial or lateral septal lesions. It is argued that these results rule out Pavlovian counterconditioning as a process which is affected by minor tranquillizers or by septal lesions when they interfere with the behavioural tolerance observed after partial punishment or partial reward schedules.

The Effects of Chlordiazepoxide on the Development of Adjunctive Drinking in Rats

Intermittent delivery of food pellets induces high levels of adjunctive drinking in rats, a pattern of behaviour which some have suggested is due to emotional arousal. In this experiment, however, chronic administration of a dose of chlordiazepoxide, a minor tranquillizer, did not prevent the development of adjunctive drinking after food pellets delivered at 1-min intervals. Indeed, the drug was found slightly to enhance the development of drinking, an effect assumed to be due to the drug's ability to facilitate the performance of several patterns of responding. When chlordiazepoxide was withdrawn a disruption in the pattern of adjunctive drinking was observed.