Bipolar or Borderline (or PTSD or ADHD)?
Managing Difficult Distinctions and Comorbidities
Bipolar disorders are in the differential for nearly every psychiatric presentation, from psychosis to depression to obsessive thinking to substance use. Three conditions present the most difficult differential diagnostic challenges relative to bipolar disorders because of the extensive overlap in diagnostic criteria and overall phenomenology: borderline personality disorder, post-traumatic stress disorder (PTSD), and attention deficit disorder (ADD). Worse, these conditions are commonly comorbid with bipolar disorders. Thus the diagnostic question is often not “this, or that?” but “this, that, or both?”
The bottom lines of this article are:
- admit the tremendous overlap in diagnostic criteria (resistance is futile)
- focus on treatment options; it takes the pressure off of difficult diagnostic distinctions
- think iteratively—start with low-risk options and adjust treatment as you go, keeping an open mind about diagnoses that might be escaping you.These principles will emerge in consideration of the three diagnoses, relative to bipolarity.
Borderlinity, not Borderline Personality Disorder
Borderline personality disorder (BPD)—what an unfortunate choice of terms. We in psychiatry who are so normal (ahem) shall deem a patient to have a “personality disorder.” Great public relations.
Nevertheless, there is a real phenomenon this label is intended to describe. Contrary to Akiskal and others, who suggested incorporating borderlinity into the bipolar spectrum (Akiskal et al., 2006), most recent data suggest that borderlinity is a different phenomenon than “bipolarity” (Ghaemi et al., 2014). The classic presentations of BPD (e.g., behaviors reflecting attachment problems, from overvaluation/devaluation to abandonment distress) are clearly different from the classic forms of Bipolar I (e.g., sustained euphoric mood, with pressured speech after two nights with no need for sleep). But as clinicians well know, there are many variations of borderlinity, often hesitatingly referred to in a diagnostic assessment as “borderline traits.”
Many authors have written about differentiating BPD and bipolar disorders. For example, Joel Paris and Donald Black (2015) emphasize getting the right treatment to the right patient, particularly psychotherapy for BPD instead of medications. Even though I disagree with their emphasis on DSM criteria to differentiate BPD from bipolar disorders, I completely agree with their emphasis on psychotherapy and avoidance of atypical antipsychotics.
In any case, controversy reigns in this area. Should you need an example, see the recent exchange between the BRIDGE team (Perugi et al., 2013) and Joel Paris (2013). Therefore, lest it be misunderstood: in the following analysis, I am not saying that some phenomenon which the “borderline” term attempts to capture does not exist. I am not saying it is a version of bipolar disorder. As the very controversy here attests, there is overlap and uncertainty about the boundaries of these two conditions. So while some research teams continue to work on distinguishing them (e.g., Coulston et al., 2012), we need some means of coping with the middle ground, where borderline traits overlap with bipolar traits...