Psychoactive drug effect on behavioural changes induced by prolonged socio-environmental deprivation in rats

Several so-called 'non-specific' or 'non-drug' factors are known to interfere with the response to psychotropic drug administration. Animal emotionality has been reported to change the outcome of psychoactive drug administration, so that the response to a stimulant or depressant drug may considerably change according to the baseline state of activity of the central nervous system. Prolonged socio-encironmental deprivation or isolation has been shown to produce in rats three different types of abnormal behaviour which have been tentatively defined as 'friendly', 'indifferent' and 'muricide'. Such unusual changes in rat behaviour are assumed to reflect a series of different emotional changes. The present experiments show that psychoactive drugs can exert a different effect in relation to the different kinds of animal behaviour used in the experiments. The investigation of the properties of psychoactive compounds, as performed in experimental animals showing behavioural alterations, is then suggested as being more fruitful in providing much information closer to the clinical results than that achieved with the experiments performed in normal laboratory animals.