Ih. Jones et al., TOWARDS A SOCIOBIOLOGICAL MODEL OF DEPRESSION - A MARSUPIAL MODEL (PETAURUS BREVICEPS), British Journal of Psychiatry, 166, 1995, pp. 475-479
Background. This is a sociobiological approach to depression using hie
rarchy and its hypothesised relevance to self-esteem in the marsupial
sugar glider (Petaurus breviceps). Method. Differential access to reso
urces between the dominant and submissive animal is measured by observ
ation in four stable colonies. The dominant animals from two of these
colonies are then introduced into the other two, resulting in the tran
sferred former dominants becoming subordinate. Behavioural and biochem
ical measures relevant to depression and involving access to resources
are then repeated. These measures include eating, drinking, social an
d sexual access, motility, grooming and biochemical estimates of corti
sol and testosterone.Results. Subordinate animals have significantly l
ess access to resources, both in the stable colony and when the former
ly dominant animals become subordinate. Conclusions. A sociobiological
approach using a hierarchy model equating resource-holding potential
with self-esteem, exemplified by this study, may provide new concepts
and insights into the phenomenology and pathophysiology of depression.
It allows comparisons to be made between animal behaviour and cogniti
on: the lack of such has been a major difficulty in animal studies hit
herto. The findings are possibly more relevant to dysthymia than to af
fective disorder and imply a relationship between low resource-holding
potential in sub-human animals as a phylogenetic antecedent of some o
f the cognitive and affective aspects of depression in man.