Депрессия: Эволюциялық теория және әлеуметтік жағдайлар

Evolutionary theory of depression
Rank theory is an evolutionary theory of depression, developed by Anthony Stevens and John Price, and proposes that depression promotes the survival of genes. Depression is an adaptive response to losing status (rank) and losing confidence in the ability to regain it. The adaptive function of the depression is to change behaviour to promote survival for someone who has been defeated. According to rank theory, depression was naturally selected to allow us to accept a subordinate role. The function of this depressive adaptation is to prevent the loser from suffering further defeat in a conflict. In the face of defeat, a behavioural process swings into action which causes the individual to cease competing and reduce their ambitions. This process is involuntary and results in the loss of energy, depressed mood, sleep disturbance, poor appetite, and loss of confidence, which are typical characteristics of depression. The outward symptoms of depression (facial expressions, constant crying, etc.) signal to others that the loser is not fit to compete, and they also discourage others from attempting to restore the loser's rank. This acceptance of a lower rank would serve to stabilise an ancestral human community, promoting the survival of any individual (or individual's genes) in the community through affording protection from other human groups, retaining access to resources, and to mates. The adaptive function of accepting a lower rank is twofold: first, it ensures that the loser truly yields and does not attempt to make a comeback, and second, the loser reassures the winner that yielding has truly taken place, so that the conflict ends, with no further damage to the loser. Social harmony is then restored.

Rank theory of depression, initially known as the 'social competition hypothesis Depression is therefore a ritualistic behaviour which fulfils an adaptive function: and competency.

One factor which may make IDS develop into major depression is arrested flight. When individuals are unable to flee from dangerous situations, this 'entrapment' may intensify the depressive symptoms, making the condition long term. As competition for social approval is particularly salient in teenage peer relations, While these theories provide "reasonably parsimonious" explanations, they are not grounded in empirical research, which severely affects their real world application.

As rank theory suggests that depression functions to inhibit aggression and stimulate submissive behaviours, one criticism is rank theory's inability to account for higher levels of anger found in depressed individuals than in controls. However, rank theorists have weakened this argument by arguing that hostility in depressed individuals is just redirected towards 'lower ranking' individuals in the social hierarchy (e. g. children) or objects (e. g. furniture).

Another criticism of rank theory is that it may not account for depressed individuals who are socially powerful and exert manipulation over others, despite supposedly engaging in submissive behaviour. To combat this criticism, rank theorists have suggested that depressed individuals only use manipulation on their supporters in order to switch support from being agonistic (i. e. intended to help the individual win in a competition by boasting) to being nurturing (i. e. accepting the individual has lost and also backing down).

As individuals at the top of hierarchies may suffer from depression, and not all those on the low end of the hierarchy exhibit depressive symptoms, critics of rank theory have also argued that the mismatch between rank and mood weakens this explanation for depression. However, this argument may over simplify rank theory, as it does not take into account the social comparison element of rank theory, which suggests that dissatisfaction with one's rank may be due to comparison with peers who have achieved higher social ranks. Moreover, rank theorists have argued that the stress of a low rank may also depend on factors such as lower rank individuals attempting to usurp you and higher rank individuals bullying you.