Globally speaking, mortality by suicide
has increased by about 60% in the past 50 years in both industrialized and
developing countries.
The risk has increased
mainly among younger subjects, and suicide is now one of the five top causes of
death among people 15-25 years old of both genders
Understanding
the reasons and the mechanics behind suicide is mandatory for developing
preventative models.
Unfortunately,
effective animal models of suicide are lacking, and suicide in nonhuman species
has not even been commonly identified by naturalists in field situations,
despite the intensive study of thousands of animal species.
Dr Antonio
Preti recently reviewed all available studies on suicide among animals.
Few empirical
investigations have been carried out on this topic: sparse evidence supports
some resemblance between the self-endangering behavior observed in the animal
kingdom, particularly in animals held in captivity or put under pressure by
environmental challenges, and suicidal behavior among humans.
Under extreme circumstances, animals subject to
extraordinary crowding, deprivation, or acute stress, may sicken and die, refusing
nourishment even when removed from distressing circumstances.
Slightly more
interesting for the understanding of the mechanics leading to suicide among
humans, where despair is a common ingredient in self-killing, are the stories
about dogs and, less often, about cats that starve to death after the loss of a
master to whom they were much attached.
In folkloric
tales, suicide following the animalŐs mourning a loss is usually accomplished
by starvation. However, the death of the animal, generally of a breed that
develops a strong bond with the master, could depend upon the animalŐs
reluctance to accept food from unknown people.
Currently, the
overall evidence on suicidal behavior among animals offers no definitive
conclusions, although naturalists could contribute by attending to the
circumstances when an animal endangers its life or exposes itself to
unnecessary risks.
The creation of
a database of observations to classify instances according to their most
evident resemblances with the characteristics observed in humans might offer a
valuable improvement of our knowledge of suicide risk factors in mankind.
All the
circumstances when an animal behaves so as to cause its death should be
recorded, to identify possible parallels with human suicidal behavior.
Clearly, a
great deal of ongoing effort will be necessary to obtain a rich and complete
enough database. However, these efforts may be rewarded by a greater
understanding of the reasons why people kill themselves.
Reference:
Preti A
Suicide among
animals: a review of evidence.
Psychological
Reports. 2007, 101: 831-848.
Contacts:
Dr Antonio
Preti
SchizophreniaProject
e-mail: apreti@tin.it