I work with a number of patients with Borderline Personality Disorder (BPD) at clinical, and was surprised at how many of them have comorbid or a history of ADHD. I was struck by the role of emotional dysregulation in both disorders, and found that differentiating between the two is a fascinating area of research and helpful in diagnosis and treatment.
Emotional regulation is an often overlooked component of ADHD, but is a major contributor to impairment (Shaw 2014). When the DSM III came out, emotional symptoms “became an ‘associated feature’ rather than a diagnostic criterion of ADHD, which shifted focus from the emotional to the attention components of the disorder. Emotion dysregulation in ADHD may arise from “deficits in orienting towards, recognizing and/or allocating attention to emotional stimuli” (Shaw 2014). In one study, 60% of ADHD patients, compared to <15% of controls, were “impatient, quick to anger, easily frustrated, and emotionally overreactive (Barkley 2009). In another, 40% of BPD patients fit the diagnosis for ADHD (Ferrer 2010). In fact, ADHD is as predictive a risk factor for BPD as PTSD.
There are three main points of view when considering the interaction between BPD and ADHD. First, that ADHD is an early form of BPD. Second, that these are distinct disorders with overlapping symptoms, one of which may contribute to the development of the other. Third, researchers are considering that in a subgroup of individuals, ADHD And BPD “may not be two distinct disorders, but represent two dimensions of one disorder” (Philipsen 2009). Before going into at that point of view further, lets look at ways of differentiating between ADHD and BPD in an assessment.
Philipsen points to clinical features helpful in working through a differential. First, the similarities: both disorders are examples of an “emotionally unstable personality in which there is a marked tendency to act impulsively” (Philipsen 2009). Affect regulation and impulse control deficits are found in both, as well as low self-esteem and substance abuse. However, how individuals experience these symptoms varies between disorders. For ADHD, symptoms arise when there is too much or too little external stimulation. For BPD, symptoms arise when they feel rejected or alone due to interpersonal conflict. Both may result in impulsivity, but the cause is different.
Another indicator is how a patient copes with their affect and impulse control issues. In ADHD, patients are more likely to “regulate inner tension” through sexual promiscuity, novelty seeking, and extreme sports. In BPD, dissociative states and self-injury are common (Philipsen 2009). The disorders also differ in personality traits. In a study on personality, neuroticism and emotional dysregulation were elevated for both groups, but significantly more for BPD (Ferrer 2010). The BPD group was low in extraversion, which is consistent with BPD criteria of “marked unstable social relationships, affective instability and inappropriate levels, and/or display of anger.” The ADHD group was no different than the control group in extraversion (Ferrer 2010).
These distinctions help when differentiating between the two, but what about when they occur together? Other researchers agree with Philipsen’s understanding of BPD/ADHD as different dimensions of one disorder. Mark Ferrer (2010) argues that comorbid ADHD and BPD can be understood as an impulsive subtype of BPD. In Ferrer’s study, comorbid BPD/ADHD patients had a significantly different presentation than the non-ADHD group. BPD-ADHD patients engaged in more impulsive behavior, notably self-harm. Those with BPD without ADHD suffered from more anxiety and depressive disorders.
Whether it is a comorbidity or an impulsive subtype of BPD, BPD/ADHD patients may be more vulnerable to acting on the chronic suicidality that often presents with BPD, especially since impulsivity in ADHD is often motor impulsivity, or “the tendency to act on the spur of the moment“ (Prada 2014). While patients with BPD are often impulsive, this motor impulsivity was found to be unique to ADHD (Prada 2014) One finding that stuck out to me is that in terms of substance use, the two groups had a significant difference in their drugs of choice. The BPD/ADHD group used more cocaine, and the BDP group used more benzodiazepines
I often hear that “borderlines are made, not born,” that underlying tendencies are brought out by unstable family dynamics and interpersonal trauma. Among BPD patients, trauma is thought to play an important role in the development of impulsivity by “altering key neural mechanisms involved in inhibition” (Prada 2014). Alternatively, ADHD is one of the most heritable mental disorders, with heritability at 80% and little research has been done into adverse childhood events and ADHD (Prada 2014). If these disorders are as interconnected as Philipsen suggests, we have to reconsider our understanding of the heritability of these conditions.
So, are BPD and ADHD separate conditions with overlapping symptoms, or are they one complex disorder with many subtypes? As with everything, the conclusion is “do more research.” This time, specifically around developing diagnostic criteria to analyze the overlapping symptoms between ADHD and BPD.
Also, just another thought:
BPD diagnosed much more often in females, ADHD in males. . Because of that, the disorders may have components that are more related to sex differences in coping. For example, is self harm diagnostic for BPD because people with BPD self harm, or because women are more likely to both self harm as a coping mechanism and be diagnosed with BPD? Is novelty seeking and extreme sports diagnostic for ADHD because people with ADHD are impulsive in these ways, or because men are both more likely to act out externally than towards the self and to be diagnosed with ADHD? Feel free to speculate about why males are more commonly diagnosed with ADHD and females with BPD in a society that normalizes emotional outbursts in men and demonizes them in women!
Barkley, R (2009) Assessing Adults With ADHD and Comorbidities. Primary Care Companion to The Journal of Clinical Psychiatry, 11(1), 25.
Ferrer, M., Andión, Ó., Matalí, J., Valero, S., Navarro, J. A., Ramos-Quiroga, J. A., … & Casas, M. (2010). Comorbid attention-deficit/hyperactivity disorder in borderline patients defines an impulsive subtype of borderline personality disorder. Journal of Personality Disorders, 24(6), 812.
Philipsen, A. (2006). Differential diagnosis and comorbidity of attention-deficit/hyperactivity disorder (ADHD) and borderline personality disorder (BPD) in adults. European Archives of Psychiatry and Clinical Neuroscience, 256(1), i42-i46.
Prada, P., Hasler, R., Baud, P., Bednarz, G., Ardu, S., Krejci, I., … & Perroud, N. (2014). Distinguishing borderline personality disorder from adult attention deficit/hyperactivity disorder: a clinical and dimensional perspective. Psychiatry research, 217(1), 107-114.
Shaw, P., Stringaris, A., Nigg, J., & Leibenluft, E. (2014). Emotion dysregulation in attention deficit hyperactivity disorder. American Journal of Psychiatry.