Is it a happy family holiday, or a desperate flight for your life?

The positive mood-altering effects of a vacation – and the chance to learn more about the world – should not be underestimated.

As the thermometer exceeds the 40°C mark, people who can plan a holiday, with a spike in travel during Eid. For months in advance, would-be vacationers have been preparing trips, dreaming of getting away from the heat, abandoning routine and breaking free from the mundane.

So, is a holiday a celebration or an escape? Everywhere in the world, tourists seek a respite, some from the heat and humidity, others from the cold and the wet. All are escaping the routine of their daily lives. The World Tourism Organization suggests that there will be 1.6 billion "getaway" holidays each year by 2020.

Tourism, no doubt, can be a very healthy activity; it's important to relieve stress by occasionally taking a break from the everyday routine. Simply planning a holiday can distract people from things they are overly occupied with, such as work, meetings, deadlines and family responsibilities.

A recent study by Jeroen Nawijn, a tourism researcher at Breda University of Applied Sciences in the Netherlands, tried to measure a holiday's effect on happiness, while also examining the longevity of post-vacation happiness. The largest boost, as expected, actually came from planning the vacation. This is something psychologists call "anticipatory savouring": experiencing imagined future pleasure in the present. Often our imagined holiday is far better than the real thing.

Perhaps a useful tip would be to plan holidays far in advance to maximise anticipatory pleasure. The Dutch study also found that among 974 vacationers, only a small minority reported feeling "very relaxed" while on holiday. Post-holiday highs were also relatively short lived, lasting no longer than two weeks.

Holidays can boost happiness and relieve stress to an extent, but there is another consideration: anything that helps us to escape problems runs the risk of becoming addictive. There are rare cases in which people appear to have become obsessed with travel, overwhelmed by urges to journey to exotic new locations. In extreme cases, such behaviour is termed dromomania (running mania), a kind of pathological tourism.

In reality, dromomania is far more complex than just wanting frequent holidays; it is generally accompanied by other psychological symptoms, such as amnesia, which is convenient if you happen to be a "what happens in Vegas, stays in Vegas" type of vacationer.

The most famous case of dromomania was identified by doctors in the latter part of the 19th century when a 26-year-old gas-fitter from Bordeaux, Jean-Albert Dadas, was diagnosed with extreme physical exhaustion. Dadas would walk up to 70 kilometres a day in year-long walking tours of Europe and beyond. On one excursion, he reportedly travelled as far as Algeria.

A medical student described how Dadas wept in his hospital room over his compulsion to abandon his house, family and job every time he had the urge to travel.

That may be an extreme case, but many of us will experience negative psychological effects after excessive, or excessively long, journeys. Probably the most common problem is jet lag, which occurs when the body's circadian rhythm (internal body clock) is disrupted as a result of crossing time zones. Depending on whether you gain or lose time, people can feel tired, irritable and weary, or slightly light-headed, invincible and giddy.

There is strong evidence linking mood disorders, such as major depression, with the type of circadian rhythm abnormalities caused by jet lag. There are even some who suggest jet lag is related to severe mental health problems such as psychosis. In vulnerable individuals, long-haul flights may trigger or exacerbate existing mood disorders.

Then again, positive mood-altering effects are part of the motive behind holidays. The world, with its different people and cultures, has so much to teach us. Let us not see holidays as an escape, but rather as a means of better appreciating the world, and ultimately ourselves.

Alanood Lari is a communication and media sciences student at Zayed University Abu Dhabi