Sufferers of Seasonal Affective Disorder, depression caused by a lack of sunlight in winter months can be treated with a new gadget that emits a powerful light.

The new “Litebook” is small enough to put onto a desk and needs to be used for only 15 minutes daily to be effective.

The condition which may affect as many as 1 in 50 people is common in winter because there is less sunlight to stimulate the part of the brain which controls mood, appetite and sleep.

Due to be launched in the UK this month, it costs £149.99. For more information, call 0845 456 7040