GENES, ENVIRONMENT AND BORDERLINE PERSONALITY DISORDER (BPD) :
Studies have been conducted that suggest that parents suffering from borderline personality disorder (BPD) may pass on certain genes to their children that predispose them to impulsive behaviour and emotional volatility.
For example, a study conducted by Distel et al. (2007) suggested that the genetic component (heritability) of BPD is about 42%, whilst a study conducted by Torgersen (2000) put the figure even higher, at 69%.
Of course, this does not mean there is a ‘gene for BPD’, but, rather, the findings suggest that certain temperamental features of an individual that are passed on genetically may increase a person’s RISK of developing BPD in later life. However, whether or not this person does develop it will depend upon the QUALITY OF THE ENVIRONMENT, WITH PARTICULAR REFERENCE TO TREATMENT BY PRIMARY CARERS, IN WHICH S/HE GROWS UP and how this INTERACTS with any genetic vulnerability to the disorder s/he has inherited.
Clearly, too, it should be noted that, as the disparity between the two percentages shows (42% and 69%), trying to quantify the heritability of disorders like BPD is a far cry from being an exact science.
MOTHERS WITH BPD :
Of course, if the mother of a child has been diagnosed with BPD, not only may her child have inherited certain temperamental characteristics (see above) that predispose him/her to develop the same disorder in later life, but, additionally, the mother may also create an environment for the developing child that compounds any genetically inherited propensity s/he may be harbouring for later being diagnosed with BPD him/herself.
Dysfunctional maternal behaviours towards the child that may increase his/her risk of developing psychopathology in later life include rejection, inconsistency (e.g oscillating between idealizing and demonizing the child), hostility, invalidation, ’emotional incest‘ and other forms of emotional abuse.
And, if the child is, by temperament, emotionally labile, his/her responses to the BPD mother’s unstable and unpredictable behaviour may serve to create a vicious-cycle of mother-child interaction.
As a result of this, the child may start displaying severe problems relating to mood (e.g. depression and anxiety) and behaviour (e.g. aggression, self-harm and hypervigilance).
PROTECTIVE FACTORS :
Children who may have inherited personality traits which increase their risk of developing BPD in later life may be protected from this most undesirable fate by consistently receiving affectionate, loving and accepting nurturing. If this is not forthcoming, therapeutic intervention (e.g. family therapy or dialectical behaviour therapy) can be of substantial benefit.
David Hosier BSc Hons; MSc; PGDE(FAHE).