Your summary of PD

[NumbLotus]

If someone asked you to summarize personality disorders in general - not a specific person or diagnosis but overall - how would you explain it?

[LemonLime]

I'd say it's a constellation of interpersonal behaviors that are of sufficient severity and predictability that they cause pervasive negative ramifications in the PD's life.  And that these behaviors are not directly caused by a known physical or mental health condition.

[GentleSoul]

Adult in a toddlers body, behaving the way a stroppy toddler does.

[Jsinjin]

I'd say it's when a person's "self" both internally and externally becomes focused on actions, morals, feelings and desires, that in most cases are single traits of behaviors, but in the case of the PD they become their singular motivation.   To the PD, they aren't wrong, there is nothing illegal, and the PD is actually the person who is right.

What I think is hard to explain is that the PD isn't hurt by their fixations like a person who has depression, alcoholism, anxiety, drug abuse, pornography addiction or other behaviors that they feel they need help with it know the consequences hurt them.    The PD genuinely believes they are right and even see questions to change their actions as an attempt to challenge their crusade.

My non-therapist background 0.02

[eyesopen]

To really simplify and summarize, I'd say it's a combination of:

1. Heightened and not well-regulated emotional response to everyday situations.
2. Negative self image / poor self esteem.
3. Inability or limited ability to be self reflective or to consider others' perspectives.

Because of each of those things, or combinations of them, the PD will...

1. Perceive reality differently than non-PDs.
2. Infer things that weren't intended (reading between the lines, they may remember what they inferred rather than what was actually said).
3. Blame others for their own problems.
4. Respond to any type of real or perceived criticism with anger, bullying, DARVO.
5. Try to manipulate others to boost the PD's ego or get the others to see things as they do (impression management, lying).
6. Have all sorts of other maladaptive responses to situations.

[doglady]

‘A personality disorder is a way of thinking, feeling and behaving that deviates from the expectations of the culture, causes distress or problems functioning, and lasts over time.‘ (American Psychiatric Association)

I don’t think I could sum it up any better than this offical definition, although I think the definitions already provided by previous posters are great.

Basically any definition that captures the deeply unreasonable nature, the emotional dysregulation, the oddness, the controlling/manipulative behaviours, the lack of accountability and the all-encompassing and pervasive view that theirs is the only one, plus the lifelong resistance to change and extreme lack of insight.

[guitarman]

Not so much a definition of personality disorders but an explanation of my uBPD/NPD sister's abusive behaviours which succinctly explains to strangers what I have experienced over a long time.

I now say to people that she frequently exhibits all the behaviours beginning with "s". That is sobbing, screaming, shouting, swearing, seeking money and suicidal.

That briefly explains what has been going on for decades without going into too many details.