I often (maybe too often) talk about the misdiagnosis of those with BPD and along with many other diagnosis I find those with BPD have been diagnosed with Schizoaffective Disorder due to the hallucinations often. Part of this I believe is also the disassociation those with Borderline Personality Disorder deal with from past trauma and other issues. The term Borderline came from the original belief that those with BPD were on the border between psychosis and neurosis. Although this is no longer the belief, some still suffer with the psychosis elements.
[source] A study of 171 Borderline personality disorder (BPD) patients revealed that 29.2% reported hallucinations. Most patients expressed that the hallucinations were distressing, occurred with great frequency over prolonged periods, took control of actions or behavior (especially, self-harming behavior) and had a critical quality. Although the majority of hallucinations were auditory, visual and olfactory hallucinations were also reported.
Hallucinations: Coping Strategies [source]
When voices are distressing, some patients may self-adjust their prescription medications or use drugs or alcohol to minimize the hallucinations. But there are better ways to deal with this issue.
Fighting back. This technique involves yelling or talking back to the hallucinations. While resisting the voices may seem like a good idea, studies show that the "fight or flight" response can lead to depression, since the voices typically don't go away on their own.
Mindfulness techniques. In a trial of a therapy called Acceptance and Commitment, participants significantly reduced the effects of their symptoms, and had slightly fewer re-hospitalizations, than a control group using traditional therapy. With this philosophy, the patient agrees to acknowledge the voices but does not agree to accept guidance from them.
For coping with delusions, not all strategies work for every person, and many people report using more than one strategy.
Distraction. Focusing on a task, reciting numbers, taking a nap, or watching television can help distract the person from delusional, often paranoid, thoughts. A recent study showed that the choice of distraction is important. Researchers found that choosing favorite music or a news program was a more effective distraction tool than white noise. The study also reported that a personal music player with headphones might be the best way to listen to music when trying to ignore delusions. Headphones minimize other distractions, and people who used them tended to stick with this technique even after the study was completed.
Religion and meditative activities. People who are religious believers report using prayer or meditation to help deal with their active schizophrenia symptoms. Yoga, exercise, or walking can also shift the focus from the delusions and provide a sense of calm.
Be selective. Some voices are positive and some voices are negative. An organization called Hearing Voices takes an interesting approach: The voices may not be physical beings, but they should still treat you with the respect that you expect from other people. This group recommends engaging with the voices, but politely. The patient should ask the voices to make an appointment, or tell the negative voices that they are not welcome until they have useful information.