Personality Disorders and Attention Deficit/Hyperactivity Disorder
A lot of people can be diagnosed with both, a Personality Disorder and Attention Deficit/Hyperactivity Disorder (AD/HD). The Diagnostic and Statistical Manual of Mental Disorders defines AD/HD as characterized by a persistent pattern of inattention and/or hyperactivity/impulsivity. This pattern has to be present before age 7, and has to be more severe than typically seen in children of the same age. It also has to be severe enough to interfere with functioning at home or at school. People with AD/HD tend to have a hard time prioritizing tasks, tend make careless mistakes, and have a hard time paying attention to detail. They mind drifts off frequently and they are easily distracted, shifting from one activity to another. Hyperactivity basically means the person is fidgety and squirmy, has a hard time sitting still and is always on the go and driven, whereas impulsivity can be described as impatience and as a difficulty with delaying gratification of an urge, on other words, difficulty with resisting the impulse to do something. For example, this can present as talking over other people and not being able to wait one’s turn.
AD/HD has been found to frequently persist into adolescence and adulthood – a national study by Kessler and colleagues indicates that about 40% of people who had childhood AD/HD continue to still have persistent and significant symptoms of AD/HD in adulthood. What’s more, last year Carlin Miller and her colleagues published a study in which they followed 96 study participants from about 9 years of age, when they were diagnosed with AD/HD, for roughly 10 years. These participants were compared to a group of 85 people who had never been diagnosed with AD/HD. The main finding of the study was that people who were diagnosed with AD/HD in childhood were more likely to meet criteria for a Personality Disorder in adulthood. In addition, those who still met criteria for AD/HD in adulthood were at increased risk for meeting criteria for Antisocial and Paranoid Personality disorder in particular. This is congruent with pervious studies on this topic that have found that AD/HD and particularly the impulsive Personality Disorders (also called Cluster B Personality Disorders, that is, Borderline Personality Disorder, Narcissistic Personality Disorder, Histrionic Personality Disorder and Antisocial Personality Disorder) tend to frequently occur together. If you look at the definition of these diagnoses, this makes sense – impulsivity is a core feature in these disorders that they have in common. This is not to say, however, that the disorders are the same thing, and this also does not mean that anyone who has AD/HD has a Personality Disorder. Conversely, not everyone with a Personality Disorder can be diagnosed with AD/HD.
As of now, we don’t know for sure what the relationship between AD/HD and Personality Disorder really is. As Miller and her colleagues point out, Some believe AD/HD could be a precursor of Personality Disorders, in that the hyperactivity, impulsivity, and inattention are early signs of the impulsivity and the difficulty in emotion regulation that we later find in adults with impulsive Personality Disorders. Another hypothesis is that having AD/HD interacts with other risk factors for Personality Disorder in a way that produces this outcome. One of the newer ideas is that both AD/HD and certain Personality Disorders may just be different expressions of another, underlying problem that is associated to these difficult symptoms and behaviors.