NEW research has revealed the winter blues not only put us in a gloomy mood - they also affect our driving.
And people in Yorkshire are the worst affected.
A new study by on-line research company YouGov has discovered that winter depression affects driving ability.
Privilege Insurance, which commissioned the research, has dubbed the phenomenon Winter Driver's Disorder (WDD).
The company says WDD causes depression, lethargy and irritability for anything from a week to a whole three months.
For the study, 2,213 people were surveyed across the UK between January 7 and 10.
Around 51% with WDD reported overtiredness and 44% were irritable. Once these people got into their cars, these symptoms transformed into road rage for 29% of them.
A further 15% had slower reaction times and 3% became reckless drivers.
Privilege Insurance claims up to 12m people in Britain could suffer from WDD.