Questions concerning the relationship between ADHD and borderline personality disorder have come into the spotlight among clinicians since they both share a great deal of both symptoms and diagnostic criteria(Matthies & Philipsen, 2014).This is especially the case when it comes to poor regulation of emotion, emotional reactivity and poor stress tolerance, moodiness, explosive anger and poor impulse control(Matthies & Philipsen, 2014). Indeed, there is an unusually large number of adults who were diagnosed with BPD as adults who were also diagnosed with ADHD in their younger years(Matthies & Philipsen, 2014). But what exactly is the nature of this comorbidity? It is merely coincidental? Do they perhaps share similar neurobiological pathways or developmental origins? Do they both result from a similar environment? It is possible that certain ADHD traits may be precursors of later BPD; a kind of nascent BPD, in at least some cases(Matthies & Philipsen, 2014).
In one study, those with ADHD were found to score much higher on borderline symptom list (BSL) scores than healthy controls. However, they did not score as highly as those who had actually been diagnosed with borderline personality disorder. There were differences, too: “The largest differences between ADHD and BPD patients were found with respect to self-destruction and affect dysregulation, whereas the smallest difference was found with respect to loneliness. Thus, at a descriptive level symptoms of BPD are common to ADHD patients, but less severe”(Matthies & Philipsen, 2014).
“The considerable overlap between symptoms of ADHD and BPD in the core domains of impulsivity and emotional dysregulation led to the idea that both disorders might be the result of different developmental pathways based on common underlying pathologic mechanisms and differing in symptom severity”(Matthies & Philipsen, 2014).
Furthermore, borderlines tend to deal with tension and emotional negativity through self-injury, tend to experienced stress-related transient paranoia and/or dissociation, suicidal behavior(Matthies & Philipsen, 2014). Borderlines also exhibit a great deal of abandonment fear and black-and-white thinking, or “splitting,” chronic suicidality, emptiness, whereas this is not something that those with ADHD typically struggle with. Likewise, those with BPD do not necessarily struggle with difficulty paying attention to things, problems in organization and executive function, or hyperactivity, which are hallmarks of ADHD. These differences in core symptoms suggest that, while there may be some type of aetiological overlap, they ought to be treated as distinct disorders(Matthies & Philipsen, 2014).
It is nonetheless undeniable that there is diagnostic overlap between the two. A 1995 study found a correlation between child ADHD and adult BPD (Matthies & Philipsen, 2014). Another study found that 14 percent of young adults who had been hyperactive as children, had gone on to develop BPD, as opposed to 3 percent of the control group (Matthies & Philipsen, 2014). In yet another study, teenagers with ADHD had a 13.5 chance of exhibiting symptoms of BPD in adulthood, as opposed to 1.2 percent in the control group. Those who were hyperactive even into adulthood, as opposed to those who had been hyperactive as kids but no longer were as adults, were almost 13 percent more likely than those whose ADHD had gone into remission, to exhibit BPD symptoms as adults (19 percent vs. 6.3 percent)(Matthies & Philipsen, 2014).
In yet another study, 27.2 percent of 372 adults with ADHD were found to exhibit the symptoms of BPD when the criteria of the Structured Clinical Interview for DSM-IV was applied(Matthies & Philipsen, 2014). In general, those who had been diagnosed with ADHD as children were a great deal to be diagnosed with personality disorders in their adulthood(Matthies & Philipsen, 2014). In another study, 18.3 percent of a sample of adults with ADHD were diagnosable with BPD. Furthermore, in this study, the more severe their ADHD had been as children, the higher the frequency of diagnosis with personality disorders in adulthood(Matthies & Philipsen, 2014).
Interesting sex differences obtained in the literature review. Of a group of 447 adults, women who had ADHD were more likely than men to exhibit symptoms of BPD(Matthies & Philipsen, 2014). Furthermore, there was significant difference when it came to specific subtypes of ADHD and their correlation with BPD. BPD was 14 percent more likely to be found in individuals who had combined type ADHD than those whose ADHD was simply inattentive, with 24 percent of the combined type patients exhibiting BPD but only 10 percent of inattentive types exhibiting it. Researchers found that BPD was particularly common among criminal offenders who had been diagnosed with ADHD(Matthies & Philipsen, 2014).
Female criminal offenders who had ADHD were much more likely to suffer from BPD (63.6 percent) than offenders who had not been diagnosed with ADHD (25.3 percent)(Matthies & Philipsen, 2014). In one study of the correlation between childhood ADHD and adult BPD symptoms, 59.5 percent of adult BPD patients retrospectively were found to score above the cut-off score on the Wender Utah Rating Scale. In this study, those who were retrospectively diagnosed with childhood ADHD as adults were much more likely to be diagnosed with adult BPD than those with non-borderline cluster B personality disorders (10.6 percent), those with either cluster A or C personality disorders (10.5 percent), healthy subjects (6.5 percent) and those who did not exhibit any symptoms of a personality disorder (5.8 percent)(Matthies & Philipsen, 2014).
Furthermore, differences in comorbidity continued to be found between different kinds of ADHD. 16.1 percent of adult BPD women suffered from combined type ADHD whereas 41.5 percent had been diagnosed with ADHD as kids. Thus, childhood ADHD appears to be a very high risk factor for the development of BPD into adulthood. Finally, a massive national population study of 34,000 adults found a lifetime comorbidity of BPD with ADHD of 33.69 percent, as opposed to a 5.17 in the general population.
The correlation betweeen ADHD and BPD appears to have a largely genetic component:
“Borderline personality traits and ADHD symptoms were assessed in a sample of 7233 twins and dsiblings from the Netherlands. The phenotypic correlation between ADHD and BPD symptoms was high (r = 0.59) and was the same for both genders. According to the authors, 49% of the high phenotypic correlation can be explained by genetic influences and 51% by environmental factors. It seems conceivable that common biological factors influencing both ADHD and BPD symptoms play a role in these overlapping psychopathological domains”(Matthies & Philipsen, 2014).
Interesting overlaps and differences between character, temperament and personality also obtained:
Temperament and character traits are hypothesized to play an important role in the developmental pathways leading to ADHD and/or BPD. In the same study, Cloninger’s temperament and character traits were also assessed. Cloninger defines dimensions of temperament (harm avoidance, novelty seeking and reward dependence) and dimensions of character (self-directedness, cooperativeness and self-transcendence). The LCA revealed a high novelty seeking temperament in all detected latent classes except for the class with a preponderance of BPD symptoms. Patients with both BPD and ADHD symptoms (all symptom domains) scored highest for novelty seeking. Higher than normal scores in harm avoidance were found in all patients with ADHD and BPD symptoms, whereas patients with ADHD symptoms only did not have elevated harm avoidance scores. Self-directedness and cooperativeness were lower than normal in patients with BPD symptoms. Van Dijke et al. concluded that above average novelty seeking temperament is more strongly linked to ADHD than to BPD. Harm avoidance, in contrast, seems more likely to be linked to BPD. Thus, ADHD patients score high on Cloninger’s temperament scales whereas BPD patients also show abnormal scores on the character scales low self-directedness and cooperativeness, a finding which points to the difference in conceptualization between the disorders: the concept of ADHD should therefore not be misclassified as a personality disorder(Matthies & Philipsen, 2014).
Swantje D Matthies and Alexandra Philipsen. Common ground in Attention Deficit
Hyperactivity Disorder (ADHD) and Borderline Personality Disorder (BPD)–review of recent findings. Retrieved from: http://www.bpded.com/content/pdf/2051-6673-1-3.pdf