Mental health articles

Early biologically-based accounts of disease claimed that a condition is a disease ifand only if it is statistically infrequent and reduces an organism’s life-expectancy orfertility. Some proponents of such an account have thought that it could work formental disorders as well as physical disorders. In a 1975 paper Robert Kendell usessuch a biologically-based account to defend psychiatry from claims that it only treatsproblems in living.25 He argues that manic-depression and schizophrenia are genuinediseases because sufferers live less long, and have fewer children, than the rest ofthe population.

The claim that diseases are conditions that reduce life-expectancy or fertilitymust be rejected, however. Reduced life-expectancy is neither a necessary nor asufficient condition for a person being diseased. People with minor diseases, forexample warts and athletes foot, live as long as anybody else. On the other handmercenaries and rock-climbers may be healthy but have short life-expectancies.Neither are health and fertility necessarily linked. Choosing to be celibate reducessomeone’s chance of having children but plausibly is not a disease.

A more sophisticated biological account of disease has been proposed byChristopher Boorse.26 Inline with the earlier biological accounts, Boorse seeks toconstruct an account whereby value judgements have no part to play in decidingwhether a condition is a disease. Whether a condition is a disease is to be determinedsolely by biological facts.

Boorse urges us to think of the human body and mind being made up ofnumerous sub-systems. “Sub-system” is used in the broadest sense imaginable,referring to organs, systems in the body such as the nervous system, and sub-systemsof the mind, for example those devoted to memory or language comprehension.27According to Boorse each sub-system has one or more functions that it performs in ahealthy human.

In other words, according to Boorse, the function of a sub-system is whatever it doesthat contributes towards achieving the goal of a goal-directed system. At first sight“goal” and “goal-directed” systems suggest that the sub-systems can only havefunctions if there is some conscious purpose behind them. Boorse, however, usesErnst Nagel’s notion of a “goal-directed system” as one that “tend[s] to persist insome integrated pattern of behaviour of activities in the face of environmentalchanges” and in which “the constituents of the system…undergo mutual adjustmentsso as to maintain this pattern in relative independence from the environment.”29Homeostatic systems, such as the system that normally acts to maintain bodytemperature, are goal-directed systems in Nagel’s sense. At a higher level, Boorseclaims, the human being as a whole can be seen as a goal-directed system that tendsto act to counteract threats to its continued survival and reproductive ability. Thus,on such an account the function of the heart is to pump blood, and this is becausethis is what the heart does that contributes towards the organism’s goal of stayingalive. When we are healthy each of our sub-systems performs its proper functionsand all is well.

Sometimes, however, a sub-system dysfunctions. In such cases there is a disease(in the broad sense of “disease” in use here, i.e. a pathological condition). Thus, aheart attack is pathological because it prevents the heart pumping blood. As anotherexample, a cut in the skin reduces the ability of the skin to perform its function ofpreventing pathogens entering the body.

In the remainder of this sub-section I shall argue that Boorse’s account isunacceptable. Although I shall argue that it is wrong, Boorse’s account issophisticated and can be adapted in various ways. Thus in the course of arguingagainst Boorse it will be necessary for me to explore ways in which his account might be improved, but it should be borne in mind that in all such cases I willeventually go on to show why these adaptations will not be enough to save him.

Tags: approaches, biological, disorder