Bipolar II Disorder and Borderline Personality Disorder - co-morbidity or spectrum?

We assess the number of patients who we have on the Database of a Community Mental Health Team in the UK who have Bipolar Disorder and Borderline Personality Disorder. We report how many of these have been seen as having both disorders. Hence we discuss the issue as to whether Borderline Personality disorder is to be placed within the bipolar spectrum. We note the difficulties regarding the use of phenomenology alone to decide this problem, and we note the similarities in genetics, neuroimaging observations and neurobiological mechanisms among the following conditions; Bipolar Disorder, Unipolar Depression, Post-traumatic Stress Disorder, and Borderline Personality Disorder. Ethiologies such as Trauma, Abuse, Childhood adversity and exposure to War appear to influence all these conditions via epigenetic mechanisms. Hence we argue that for a spectrum to be proposed, conditions in the spectrum need to be underpinned by similar or common Neuroimaging and neurobiological mechanisms.On this basis, it may be reasonable to include Borderline Personality Disorder within a broadly described bipolar spectrum. New details of the common Neurobiological mechanisms continue to emerge.