Bendigo has endured a long hot dry summer with rainfall half the annual average. As you drive around the suburbs it is evident that some plants and shrubs haven’t survived. Our tall cypress hedge was a casualty although some experts point to the Cyprus canker as the culprit. Fungal spores enter a tree through wounds in the bark which could be pruning cuts, cracks, insect holes, or storm damage to limbs. However it is also evident the long period of dry conditions weakened the trees, particularly the root systems.
A friend who has lived in the area for many years believes that many of the problems we are seeing are the result of poor spring rains. She maintains that long hot dry summers are to be expected but when you don’t get the rains you should then the soil becomes very dry and the survival of some plants put in jeopardy.
When assessing the causes of suicide we are drawn to the more obvious and immediate concerns being faced by the person. They are known as proximal risk factors as they are more closely related temporarily to the suicide event itself. Proximal risk factors may include a major loss or stressful event, feelings of hopelessness, the onset of physical illness, exposure to a suicide, or recent alcohol and substance abuse. Proximal risk factors are not sufficient in themselves to cause a person to take their life.
On the other hand distal risk factors represent background characteristics or underlying vulnerabilities that heighten a person’s risk for a suicide attempt in their lifetime, but not immediately. Distal risk factors embody the foundation upon which suicidal behaviour is built. Distal risk factors include developmental, personality, biological, and genetic variables, along with impulsive- aggressive personality traits that create a predisposing diathesis and determine the individual’s response to a stressor. (Oquendo et al. 2008) Their relationship to suicide is fundamental but indirect; they are considered necessary, but not sufficient, for suicide to occur.
Although there is some research suggesting the existence of a specific gene linked to suicidal behaviour I don’t accept that genes alone are the direct cause of suicides.
Genetic factors play an important role in the predisposition to suicide and suicidal behaviours. While there is strong support for familial and genetic factors increasing vulnerability to suicidal behaviour, it is unlikely that genes have direct effects on suicide itself. Many crucial questions remain, specifically concerning the overlap between the influence of genes on suicide and the genetic predisposition to psychiatric illness.
The general idea is that the genetic effects of suicide act through intermediate factors, a sort of go-between, which link genes and suicidal behaviour. For instance, personality characteristics such as being very impulsive or very anxious are good examples. Both of these so-called personality traits have a genetic component themselves. So, individuals who are genetically predisposed to be very impulsive may, under certain conditions, be at increased risk of suicide. (Violette & Turecki, 2013)
Oquendo, MA., Mann, JJ. (2008) Suicidal behaviour: a developmental perspective. Psychiatric Clinic of North America. 31(2): xiii-xvi.
Violette, R. & Turecki, G. (2013) Genetics of suicide. McGill Group for Suicide Studies, Department of Psychiatry, McGill University, Montréal, Québec, Canada.