Every day, we hear endless tragic news stories about people killing and abusing family members, co-workers or innocent bystanders. We’re constantly shocked when people we know (or well-known public figures) commit suicide.

Do you ever ask yourself why the family and close friends of these people didn’t intercede before it was too late?

The reason is that very few of us learn to recognise the symptoms of serious mental illnesses (like

,

, etc). We just shrug those signs off as annoying quirks or personality idiosyncrasies when they appear in people

we

know.

As a result of glazing over obvious symptoms and behaviors, serious psychological conditions often go unnoticed because the person in question is still able to work, drive, have

, have children and even achieve success in their professional life.

Because those people function somewhat well in society (and in our lives), we discount and just put up with their puzzling behavior … even when, because of their emotional dysfunction, they’re challenging to live with and love, causing you and those closest to them to suffer physically or emotionally.

"What Sandy didn't know was that Rob was contemplating suicide." Image: iStock.

So, here are four

that are far more common than you realise, and how to recognise their hallmark, symptomatic behaviors:

Sixty-year-old Sandy was still suffering from a terrible trauma that occurred in her 20s. During her senior year in college she fell in love with Rob, her dream man. He was finishing medical school in a distant city. This, of course, happened before email and cell phones, so they wrote daily love letters and looked forward to the occasional weekends they could spend together. Rob wrote how sad he was without Sandy and how dark life seemed. He was lonely and stressed. Sandy thought all of this was tremendously romantic.

After graduation they

and Rob began a gruelling internship at a large hospital, while Sandy entered graduate school. Rob wasn’t eating enough or resting enough. He felt depressed, but Sandy attributed his agitation and exhaustion to the demands of his internship.

What Sandy didn't know was that Rob was contemplating suicide. One day, when she arrived home after school she found him dead. She still can't forgive herself for not recognising these warning signs:

Denise ended up in the hospital for treatment for her deep

after her mother died. With treatment she was able to get a job and function pretty well. The only problem was that she began to spend and spend (and spend)! She went through her entire inheritance and had little to show for it. Denise suffered from serious mood swings throughout her life. She was eventually diagnosed as being bipolar.

This serious problem requires ongoing medical supervision since the primary symptoms are dramatic and unpredictable mood swings. The illness has two contrasting phases, feeling up or down.

Symptoms to look for in the depressed (or "down") stage are:

Symptoms to look for in the manic (or "up") stage are:

Priscilla was unhappily married to Victor for over 10 years and was unable to get him to change. She discovered that he had an affair, and it wasn't the first time. Victor constantly blamed Priscilla for everything, constantly lied to her, and even forged her name on important legal documents. As a result, Priscilla lost her home, her job, and her

due to his heartlessness.

"Their biology shows that they do not have the mental capacity for empathy or understanding." Image: iStock.

People like Victor are often highly intelligent and successful, but leave a trail of unhappy victims behind. Here are some of the qualities of sociopaths that destroy loving relationships. This person is:

Scientists have

of these people and have discovered that their brains are, in fact, different. Their biology shows that they do not have the mental capacity for empathy or understanding. Take care to protect yourself and your loved ones when this kind of person is in your life.

If you are in a relationship with someone who makes you feel like you must constantly walk on eggshells because you never know whether you'll see Dr Jekyl or Mr/Ms Hyde at the breakfast table, there's a chance you're involved with a Borderline Personality. People with this illness often have very tumultuous relationships. It can feel like you're riding a love-hate rollercoaster. They may have a tantrum over minor misunderstandings and often have difficulty accepting grey areas - things appear as either black or white.

Look for these traits:

Don't glaze over the warning signs if the one you love has patterns of long lasting troubled behavior or has a history of

. Learn more about these problems before you make a lifetime commitment. If the relationship is causing you significant stress, you may find it helpful to see a therapist yourself.

Enjoy a free consult with Gloria to discuss your relationship problem. Find out more about relationship challenges in her book

. Make sure to download Gloria’s FREE book Creating Happiness.