Yesterday was the most unproductive day of the year, according to a survey, as workers' morale is hit by the darker evenings brought on by the clock change.

Researchers found productivity will drop by 50 per cent this week as depressed staff around the country struggle to come to terms with the dark nights closing in.

A staggering 52 per cent of workers admitted they struggled to get to grips with their work-load on Monday.

And 14 per cent said last year's slump was so bad that they were spoken to by their boss about it.

Worryingly for employers, eight per cent even admitted to phoning in sick because they were so depressed at the thought of going to work amid the shorter, darker days.

The stats emerged in a study of 2,000 workers by Promotur, The Canary Island tourism board.

On Sunday, Dr. Christian Jessen of Channel 4's Embarrassing Illnesses, said: "The Winter Blues are no joke.

"They can affect your work performance by making you unable to concentrate and carry out your normal routine, your relationship by affecting your libido and your social life by making you feel irritable and anti-social.

"Feeling low as the nights draw in and the days get shorter is something many people experience, but some will struggle with lack of motivation, tiredness and depression.

"If you find the winter months tough, particularly during December and January you may suffer from Seasonal Affective Disorder, which causes a low mood caused by the lack of light during winter.

"It's thought to affect two million people in the UK and the best treatment is to get more light.

"If these all ring bells then you may be a sufferer and should consider ways you can get more light into your life over winter."

一项调查表明，昨天（10月26日）是这一年中人们工作效率最低的一天，由于本周冬令时开始，黑夜变长，人们的工作积极性也受到了打击。

调查人员发现，本周人们的工作效率将会下降50%,因为全国郁闷的"上班族"们正努力适应黑夜的"来袭".

多达52%的员工承认昨天他们只是勉强应付了工作。

14%的受访者称去年的经济衰退程度之深，以至于老板还专门找他们讨论了这一问题。

让雇主们担忧的是，8%的受访职员甚至坦言自己谎称生病请了假，因为他们一想到在白天变短、黑夜变长的日子里还要工作就感到郁闷。

这些数据来自加纳利群岛分管旅游的Promotur机构对两千名职员开展的一项调查。

在上周日（BBC）第四频道的节目《让人困窘的疾病》中，克里斯蒂安？杰森医生说："冬季抑郁可不是闹着玩的。

"冬季抑郁会让人无法集中精力，完成日常工作，从而影响你的工作表现；它会影响性欲，从而影响你和伴侣之间的关系；此外，它还会让人感到焦躁易怒和厌恶社交，从而影响你的社会交际。

"很多人在黑夜变长、白天变短的冬季都会感到心情低落，但有些人则会感到缺乏动力、疲倦和抑郁。

"如果你觉得冬天很难熬，特别是在十二月和一月份，那么你可能患上了'季节性情绪失调',这是由于冬日里缺少阳光而引起的情绪低落。

"有说法称，英国有两百万人患有这种季节性的情绪失调，而最好的治疗方法就是多接触阳光。

"如果你有以上这些症状，那么你可能患上了季节性情绪失调，那就应该考虑一下如何在冬季让自己的生活多一些阳光了。"