Borderline Personality Disorder

Borderline Personality Disorder (BPD) is a serious mental disorder marked by a pattern of ongoing instability in moods, behavior, self-image, and functioning. These experiences often result in impulsive actions and unstable relationships. A person with BPD may experience intense episodes of anger, depression, and anxiety that may last from only a few hours to days.

Association of BPD and CFS
From BJ Psych Open under heading BPD in patients with CFS: "There does not appear to be firm and consistent evidence to support the hypothesis that the prevalence of BPD is higher in individuals with CFS than in the general population."