Sorry in advance. This will be long but informative.
WHAT IS PSYCHOSIS? (http://www.cedarclinic.org/index.php/understanding-early-psychosis/what-is-psychosis)
Psychosis is a set of symptoms that involve a person’s mind “playing tricks on him or her.” The person experiencing psychosis may have difficulty telling the difference between his or her own thoughts and perceptions and those that come from the outside world. Although real to the person experiencing psychosis, psychotic experiences are not experienced as real to others. In fact, as a medical term, psychosis refers to a loss of contact with reality, or difficulty telling what is real from what is not real.
Psychosis is more common than many people think. Symptoms may come and go or be relatively constant. It is often associated with mental health disorders like depression, bipolar disorder, and schizophrenia. However, psychosis can also occur for many other reasons, including substance abuse, brain injury, seizure disorders, or conditions of extreme sleep deprivation or isolation.
SYMPTOMS OF PSYCHOSIS (Mayo Clinic and Others)
People may experience:
Behavioral: disorganized behavior, aggression, agitation, hostility, hyperactivity, hypervigilance, nonsense word repetition, repetitive movements, restlessness, self-harm, social isolation, lack of restraint, or persistent repetition of words or actions
Cognitive: thought disorder, belief that an ordinary event has special and personal meaning, belief that thoughts aren’t one’s own, disorientation, memory loss, racing thoughts, slowness in activity, thoughts of suicide, unwanted thoughts, difficulty thinking and understanding, or false belief of superiority
Mood: anger, anxiety, apathy, excitement, feeling detached from self, general discontent, limited range of emotions, loneliness, or nervousness
Psychological: fear, hearing voices, depression, manic episode, paranoia, persecutory delusion, religious delusion, or visual hallucinations
Speech: deficiency of speech, excessive wordiness, incoherent speech, or rapid and frenzied speaking
Also common: confusion, nightmares, or tactile hallucination
HOW PSYCHOSIS AND BPD RELATE
Other than many (or all) of the above items relating to my personal episodes of BPD, there are a couple of other things I read that I feel also relate.
Other similar difficulties between Psychosis and BPD:
1. Withdrawal from the outside world, including from one’s family, friends, and even one’s own self (often due to a drop in or “absence” of interest or ability to relate to others)
2. Trouble thinking clearly and communicating with others (the person may talk very little or very rapidly)
3. Trouble interpreting social cues of others
3. When stressed, people with borderline personality disorder may develop psychotic-like symptoms. They experience a distortion of their perceptions or beliefs rather than a distinct break with reality. Especially in close relationships, they tend to misinterpret or amplify what other people feel about them. For example, they may assume a friend or family member is having extremely hateful feelings toward them, when the person may be only mildly annoyed or angry. (https://www.drugs.com/health-guide/borderline-personality-disorder.html)