When was the last time you kissed passionately?

If you can't remember you could be in trouble. Never mind the agonies of living a sexless life, a jobless life or even a penniless life -- it's a kiss-less life that could be the hallmark of misery on a number of levels.

Yes, I made up that word -- kiss-less -- because all the while we don't have a word for living without kissing we could be overlooking one of the leading causes and indicators of unhappiness in our time.

Sound far-fetched? A first-world problem? Bear with me...

Everything from our mental, emotional and physical health to our relationship satisfaction can be improved by regular, intimate kissing.

In case you are in any doubt, I am primarily talking about passionate, heartfelt adult kisses, usually on the mouth and often sexual but not necessarily so.

Shakespeare himself, in King Henry VI, said: "I can express no kinder sign of love, than this kind kiss."

But it's not just literature that has long hailed the superlative powers of kissing -- there is some science to back it up too.

Isn't this really all about love? Yes, partly, but as it turns out, kissing could be a better barometer of love (in couples) than almost anything else, including sex. After all, people don't have sex for a number of reasons, but about the only excuse for not kissing is a lack of love, affection or intimacy.

And kissing creates more warm feelings by triggering a surge of oxytocin (in men) -- the love hormone -- boosting our nurturing instincts. Research also suggests couples who kiss more are happier, healthier and more likely to stay together.

Family communications scholar, Kory Floyd, and his colleagues at Arizona State University, examined this phenomenon several years ago. Fifty-two long-term relationship participants were randomly assigned into two groups. Members of the experimental group were instructed to kiss their partners more for six weeks.

Blood tests and questionnaire data collected before and after showed that members of the experimental group experienced lowered cholesterol, decreased stress, and improved quality of relationships.

A kiss can dissolve stress. Researcher Wendy Hill, of Lafayette College in Pennsylvania, found that kissing for fifteen minutes led to a significant drop in the level of the stress hormone cortisol.

A kiss is a bond of trust. Studies on the role of kissing in mate selection might partly explain why. One hypothesis is that the glands of the face and mouth communicate imperceptible genetic, immunological and hormonal information. If this biochemical potion is well received, a deep reciprocal kiss will ensue, establishing or maintaining primal feelings of acceptance, approval and an intense sense of wellbeing.

This might also explain the 'turning away from a kiss' phenomenon and why some kisses are bland, phoney or forgettable while others are intimately and indelibly life affirming.

Perhaps Sylvia Plath was more accurate than she knew when she said: "Kiss me and you will see how important I am."

A kiss can keep hope alive. One of the most poignant photos of 2015 was that of a couple kissing inside a tent on a packed refugee site in Keleti station in Budapest (Sept 2015). The photo, A Kiss Knows no Borders, by Istvan Zsiros, went viral and captured the hearts of millions. Even when sex, food, safety, warmth and health are compromised, the power of a kiss can be transformative.

Why do I feel so evangelical about all this? Well, I have lived through the bliss of kissful (another new word) relationships and the emotional wasteland of kiss-less ones and seen my health and happiness soar in the former and crumble in the latter.

Like many others, in the course of my life I have survived painful separations, paralysing losses, life threatening illness and heart stopping betrayals. In the end, some of the most potent soul restoring magic was to be found in the tender kisses of friends, lovers and occasionally even strangers.

Self-medicating? Perhaps, but those kisses helped me heal. They soothed my spirit and imbued my mind and body with more will to live than any amount of therapy or medication could.

But what recently renewed my belief in kissing was a Facebook status update I ran asking my friends "What's in a Kiss?" for a feature I was writing about the health benefits of kissing.

I was surprised and moved by the number and intensity of the private messages I received, of just how important kissing, or the lack of it, is to people.

One middle-aged man, who preferred not to be named, expressed it beautifully: "With all the objectivity of distance, what keeps coming back to me is how much more important kissing is than almost any other single act in a relationship.

"The essence of kissing is all about intimacy and communication...the kind of kiss that really fires my imagination is the one that establishes intimacy -- or re-establishes it for the thousandth time."

As a disabled man, he also reflected: "I could probably -- very reluctantly -- accept the idea that there is little likelihood of a sexual relationship again, but the idea of never knowing the intimacy of kissing again would be quite devastating."

Regular, passionate kissing could be one of the best tools we have for measuring, predicting and enhancing the joy in our lives. That's why it's time for a kissing revival, time to acknowledge the sorrow of a kiss-less life, time to increase the frequency and quality of our kisses.

It's time to kiss like your life depends on it.