I'm inclined to agree that I think borderline personality disorder is a real possibility. I know some will not like this speculation about her mental health but her mental health is relevant to the crime according to statements her attorney made in court and the court appointed psych agreed that further evaluation is needed before the hearing December 11th, so if someone forced me to form an opinion solely on what we have been told and my own research, I would say that I think she suffers from borderline personality disorder, maybe co occurring with depression and/or anxiety. It was also reported that she had issues with body image which is very common with borderline personality disorder as is suicidial ideation and attempts, which has also been reported in regards to Abi. This personality disorder is difficult to diagnose in many cases and it's unfortunate because there are many people with this disorder that don't know they have it. There are also many others who are aware and take steps to help control it and find an appropriate therapeutic approach.
According to the NIMH, people with severe borderline personality disorder can experience psychotic episodes as well. Their website has a list of symptoms of which an individual must have an "enduring pattern of behavior" of five of the symptoms to be diagnosed. Here is the list, and a link to the source from the NIMH:
*Extreme Reactions-including panic, depression, rage, or frantic actions-to abandonment, whether real or perceived
*A pattern of intense and stormy relationships with family, friends, and loved ones, often veering from extreme closeness and love to extreme dislike and anger
*Distorted and unstable self-image or sense of self, which can result in sudden changes in feelings, opinions, values, or plans and goals for the future (such as school or career choices)
*Impulsive and often dangerous behaviors, such as spending sprees, unsafe sex, substance abuse, reckless driving, and binge eating
*Recurring suicidal behaviors or threats, or self-harming behavior, such as cutting
*Intense and highly changeable moods, with each episode lasting from a few hours to a few days
*Chronic feelings of emptiness and/or boredom
*Inappropriate, intense anger or problems controlling anger
*Having stress-related paranoid thoughts or severe dissociative symptoms, such as feeling cut off from oneself, observing oneself from outside the body, or losing touch with reality.
Source: National Institute of Mental Health
http://www.nimh.nih.gov/health/topics/borderline-personality-disorder/index.shtml
Take that for what it's worth, but at a quick glance there are definitely at least five things on this list that fit with what's been reported in msm, and could shed light on The horrific crime she committed (not that it's an excuse at all). There's more info at the link above.