Could one identical twin have Borderline personality disorder while the other doesn't?
Yep. Twin studies have found that if one identical twin has BPD, the chance of the other having BPD ranges from 37% to 69% - so it’s definitely possible. Go forth and write your story!
Hi, not sure if this is the right 'script family' blog to ask this of, but I have two adult male identical twin characters who spent their adolescent years apart. I'm planning for one to have ADHD and the other to have depression, but I'm wondering if this would be possible? Or is it more likely they'd both have one/both mental health issues rather than one each?
It is indeed possible! One of the preferred methods of studying the causes of mental illness are called “twin studies”. Basically, psychologists look at identical and non-identical twins to see how often they share the same diagnoses.
ADHD is incredibly likely to coincide in identical twins, but the rate is not 100% - it’s around 82%. So it’s definitely possible for one of your characters to have ADHD and the other not!
Depression also has a high rate of coinciding in identical twins (around 76%), BUT when the twins are raised apart, the rate drops to around 67%. The rate drops because there is a definite environmental component to developing depression.
So it’s definitely possible! Go forth, and write your story!
