Brief Advice About Dealing With People Who May Have A Personality Disorder Or Mental Illness

Some unsolicited advice (take what you need and leave the rest) about relating with people who you suspect are showing signs of narcissism or similar disorder:

Make self-care your priority. Those with Narcissism make self-care their main and only priority, instead of caring for others. Those with codependency issues make caring for OTHERS their top priority, instead of caring for themselves. Both are often resentful toward others who need or request care from them. Those with codependency tend to believe that caring for themselves first indicates self-centeredness and selfishness, and can feel shame when they try to heal their boundaries or care for and protect themselves, making it very difficult and anxiety-producing to change this behavior.

Keep your guard up, but don't be obvious; if a person with certain Personality Disorders or mental illness detects that your guard is up, they might get offended (narcissist injury: how dare you even think that for a second about me), OR fear that you are going to hurt them in some way because you're acting distant and strange, and may attack, retaliate, or become very anxious or fearful of you (depending on what's going on with them emotionally or mentally).

Do behave courteously, politely, and civilly, treat them with good manners, like you would anyone else, or even moreso. That's both about you and about dealing with them. Those with certain disorders are scanning constantly for any indication that a person is not being polite, courteous, or fair, and some (not all) will use that as an excuse to retaliate. If a person who has narcissism misinterprets something as disrespect, they may not ask about it and wait for an answer, they'll accuse and attack. So tread lightly and carefully when possible, and since this can be difficult to keep up in a stressful situation, don't prolong the visit. Keep it as short as possible, as formal and light as possible, for your own sake, and for the sake of everyone else nearby. (This one is hard for a lot of people, but it can reduce a lot of chaos and stress by preventing reactions and retaliations.)

Don't try to save them, don't try to cure them, don't diagnose them, don't try to fix them, don't badger them about getting help. They are a human being with free will. If the person is a loved one, then of course you can seek advice by consulting a counselor, doctor, healer, but unless they are your underaged child, you can't make them get counseling. If they are your spouse/partner, then you do have some say regarding the way they are behaving that affects you or your children, and you can go to a counselor or doctor yourself, and then ask your partner to accompany you. If they're abusive, you may need to just leave and then see if anything can be done, or should be, after you and your children are safe.
The truth is, psychiatry and psychology is not the kind of science that's concrete like biology, zoology, or geology. There's a lot of theory, a lot of abstract speculation, and a lot of blurred lines. Origins of "mental illness" and "personality disorders" are being studied all the time, but are not fully understood or agreed on. It might look like a person has Bipolar Disorder, but it may turn out that their issues are actually from Trauma, for example.
Some things are clear and obvious, like if someone has brain damage, but psychologists and psychiatrists don't usually even do tests to find things like that out unless there are specific signs of a certain neurological issue. That would fall to a Neurologist.

Protect yourself, protect your children. Do it discreetly, not obviously. In other words, do the "Oh dear look at the time! I am late, late, late! It was so good to see you, take care!" and NOT the "What the hell were you thinking?! Are you kidding me?" or the "You're late AGAIN! You obviously don't give a crap about anyone but yourself!"
This is again, about damage control and prevention. If you think they have Narcissism, for real, then it will only cause them to freak out if you accuse them or if you react. Don't rage, don't retaliate, don't yell at them, don't show your frustration or anger to them. That's not an edict about generally not showing emotional expression in your life, this is specifically about interaction with a person who you suspect has Narcissism or another reactive illness or disorder.
When kids are involved, it's even more important to tread carefully and act civilly; everything affects them, both the N's behavior and the non-N's behavior. Protecting children from a reactive person can be a delicate operation, and a very important one. If the person is abusive, find a way to keep the children away from them in the least obvious way possible, if you can, to avoid provoking the person. If you need help, and you may, seek legal help, and also advice and support from a psychology professional/ counselor who understands narcissism, and your situation.
The reactions of those who actually have retaliation issues are often fast and volatile, often over the top, and can cause real damage.
It's got nothing to do with "who's FAULT" it is, blaming, or holding them accountable; it's about prevention and damage control, which they are not going to do, so it falls to you.

Don't talk details about your money situation, especially if you suspect the person has Narcissism, if you can possibly avoid it. Whether it's good or not so good; whether you just won the lottery, just got a raise, just signed a contract, or whether you're behind the 8-ball or are looking for a way to resolve a problem.
It's common for a Narcissist to either actually be good with money, so they're financially stable or wealthy, and we naturally want to ask them for advice or help. It's ALSO common for an N. (or any other person who has ego issues) to THINK that they're good with money (better than you), and that it means they're a better person than others. It's also common for a Narcissist to use their own money or wealth as a way to control and manipulate others, AND/OR to use both a target's money problems AND winfalls against them, for domination and control purposes.
People who have Narcissism, and also some other personality disorder/mental illness issues, can be very envious of a person who has more money than they do, EVEN IF "more money" only means getting 25 cents more an hour in one's paycheck than they do. They are also unempathetic toward a person who is barely scraping by, and will not have qualms about taking their last five dollars.
~So it doesn't matter whether a person with Narcissism is wealthy or poor, or is ACTUALLY good with money or just thinks they are; the odds of them trying to use the details of your financial status and situation for control, guilt, shame, or manipulation purposes are very high.

Don't seek support from them, like you would a "good friend", especially if you aren't sure what's going on with them. Certain Personality Disorders/Mental Illnesses will view personal details as "flaws" or "weakness", and some may use details that a person discloses to them for gossip fodder or sabotage purposes. Others may even get a kick out of invalidating you and "kicking you" when you're down, and still others will use your support seeking as an opportunity to dominate you and display "superiority".

Get support from a person whom you genuinely trust and respect, and try to find someone who you can interact with face to face. A person who you trust will NOT spread gossip, who will NOT judge, attack or hate the person you suspect has Narcissism (or other disorder). A trustworthy person who will NOT turn on you. A person who has not shown a propensity for being "two-faced" or manipulative. Don't worry about them being the best and greatest listener or counselor in the world, it's really more important that they are trustworthy, and not inclined to gossip, dominate, invalidate, or judge, and also who won't turn on you because they fear the other person. If you have to pay someone to be that support, (a counselor), then do that. Sometimes it's the only way to find it, so then that's what it takes.

Be aware of your anxiety levels. It has been found that anxiety is actually a reaction from carbon dioxide build-up. Concentrate on your breath, control your breathing. One person can end up in a panic attack from losing a five dollar bill, and another can walk past a crocodile with calm composure. It's not just innate courage or stress endurance, it's also directly related to our breathing.

Learn what "boundaries" are. If you already know, then learn more, review what you've already learned. Talk about it with someone. Healing boundaries is key in recovery and in dealing with current situations.

Don't be too hard on yourself about fatigue, losing concentration, and letting things pile up. Do pay attention, but don't increase your stress by railing on yourself because you aren't keeping the same schedule or keeping everything spotless and organized. The stress from relating with people who have possible mental illness or P.D's can cause serious fatigue, even if that illness is temporary, from a physical illness, age, or from trauma that happened to them. The stress we feel is from how we ourselves are dealing with what's happening, more so than what they are doing ~ (obviously the more severe the behavior, the more stress it would cause anyone, but we always have the ability to reduce our own stress to some degree, we just need the "how"). 

Watch your language (for real) and pay attention to the language and behaviors of people you're interacting with. We can actually set ourselves up for more stress, and often do, by using hostile, aggressive, or 'ugly' language, especially when we keep using it. Also, by being around people who's speech and manner is hostile and aggressive. On a conscious level, we can feel like we're getting our aggression out, venting, and feeling strong and powerful, but if we keep repeating hostile language and behaviors, and exposing ourselves to others who repeat them, we can actually keep ourselves in a loop of reaction and anxiety without realizing it.

Last one, same as the first:
Make self-care your priority. Those with Narcissism make self-care their ONLY priority, INSTEAD OF care for others. Those with codependency issues make caring for OTHERS their top priority, instead of caring for themselves.
Shame and blame play a role in both of these behavioral patterns.
Narcissists can feel justified in putting their self-care first and only "because no one else is going to do it", but they reject and resent caring for others, which means they're actually doing what they're using as a justification for their own behavior. Also, Narcissists can feel very resentful about having to share, care, and compromise, even in small ways that would benefit themselves.
Codependents, on the other hand, will do the opposite; they care for and give to others first, INSTEAD OF themselves, to the detriment of their own life, career, future, financial well-being, mental and emotional well-being, reputation, and health. They were most likely "trained" directly or indirectly to do this during their childhood and youth, and may believe that NOT being this way would mean being a bad person.
Both Narcissists and Codependents are missing the bigger picture about how the world works and how human beings need both cooperation and respect for optimum functioning.

The example about oxygen masks on planes demonstrates this very well. Airlines instruct passengers that in the event of an emergency, when the oxygen masks drop from the ceiling, for each person to put their OWN MASK ON FIRST, AND THEN HELP WHOEVER IS NEARBY. We put the oxygen mask on ourselves first, so we can breathe, so we have strength, so we can function. Then, as soon as ours is secure on our face, we help whoever is nearby put theirs on. We don't help them first, we help them second. But we help them, we don't ignore them, and we help them QUICKLY, IMMEDIATELY, as soon as OUR mask is in place and helping us to breathe. We don't trade our life for theirs, and then not be able to help anyone ever again... because we're dead... NOR do we trade THEIR lives for ours, ignoring their struggles, refusing them help. We do BOTH things, save ourselves AND help them, in that order.

Both Narcissists and Codependents seem to see it as a CHOICE between ourselves and the other person, EVERY TIME, in EVERY INSTANCE.
The realistic fact is that we're hardly EVER faced with that kind of choice.
We can pretend that it happens all the time, and we can embellish and create situations that seem like it's happening in order to feel justified, but unless our personal living situation is dire and there's no relief in sight, then being forced to make a choice between our own life and someone else's is a rare event

(An important note: those who have lived through life-threatening events in real life, and especially where they did make a choice to sacrifice themselves for someone else but survived, may have PTSD, and may actually be trying to deal with their trauma by recreating similar situations in their lives, seeking resolution and closure. However without competent help it can turn into a pattern, especially if they're not aware that they're traumatized).

That happens all the time in the movies, because it's MOVIES, not real life. The drama is there to make the story interesting. We can also find this in a lot of religious texts; again, when a martyr sacrificed their life for others, they only did it ONCE. A "martyr" is a person who literally gives their life for the life of another, or others, in order to save them. One is not a martyr if one gives over the money for their rent every other month in order to give someone else car payment money. Nor is one a martyr if one gives away their resources or their life just to prove that they are a "good enough person". If there's no one in immediate danger of losing their life or their soul, honestly, then why give away everything, one's resources or one's life, when both of those things are such precious gifts and could have been used to help others on a larger scale, over a longer time period?

Put the oxygen mask on one's own face first, and when the oxygen is flowing, then turn and help those nearby who need help, right away, without prejudice.
When we are strong and healthy because we are taking care of ourselves, we are able to be supportive of others in a healthy way, and can much better discern if someone is manipulating us, or if they're NOT. And, when we're strong and healthy, we can take a heck of a lot more bumps and bruises, and are much more able to protect ourselves and our loved ones when we happen to run into a manipulator.

For healing from abuse, seek sanctuary. Seek support, knowledge, traditional healing and counseling, spiritual counseling, and safe forms of spiritual and emotional healing. Make contact with animals, plants, nature, they are filled with life force and spirit. Sit in sun rays. Sleep. Eat well. Take warm baths. Pray. Love yourself.