Explaining BPD In Terms Of The Diathesis-Stress Model

What Does ‘Diathesis’ Mean?

The medical definition of ‘diathesis’ is ‘a heriditary or constitutional predisposition to a disease or other disorder.‘ (The word ‘diathesis’ itself derives from the Greek word for ‘disposition).

What Is The Diathesis-Stress Model?

The diathesis-stress model is a psychological theory that proposes that a psychiatric disorder is caused not by heriditary factors (i.e. predispositional vulnerability)alone, NOR by psychologically stressful experiencesalone, but by the way in which the two factors interact with one another.

The diathesis-stress model is an appropriate model with which to explain how borderline personality disorder (BPD) develops in the individual. It is appropriate because research suggests that BPD does not occur in a person solely because of his/her traumatic and stressful childhood experiences nor solely because of an unfortunate genetic inheritance. What is vital in determining whether or not a person ‘succumbs’ to BPD is how their genes and childhood experiences combine and interact.

In other words, a person who is genetically vulnerable to developing BPD and experiences severe, protracted trauma during childhood may well go on to suffer from BPD in adulthood (see equation 1, below)

However, another individual who has low genetic vulnerability to the disorder and suffers a similarly traumatic childhood (although, of course, the ‘amount’ of trauma a person experiences is impossible to quantify – each case is utterly unique) may well avoid developing it (see equation 2, below)

So, we could represent the above with the following equations :

1) HIGH LEVEL OF CHILDHOOD TRAUMA + HIGH GENETIC VULNERABILITY = HIGH CHANCE OF DEVELOPING BPD.

More About Genetic Vulnerabilty To BPD :

In terms of genetic inheritance, what will make a person more susceptible to developing BPD?

The main consideration here is the person’s innate temperament. In particular, those who have naturally impulsive and emotionally labile personalities will, in general, be more predisposed to developing BPD if they also experience protracted and significant trauma during their childhoods compared to those more naturally inclined towards stoicism and timidity.

A Third Factor : Culture / Society :

However, the stress-diathesis model is not the whole story when we are considering the multiple, inter-relating causes that can lead to someone developing BPD. There is also the question of the culture / society in which the individual exists.