Seasonal affective disorder (SAD) is under diagnosed in primary care and can be confused with other disorders, an American doctor has warned.
SAD has been linked with alcoholism and attention deficit hyperactivity disorder (ADHD).
Patients with seasonal alcohol abuse could be self medicating to cope with underlying depression.
Stephen Lurie, assistant professor of family medicine at the University of Rochester Medical Center, said patients with a mental illness should not assume any new mental problem was due to that.
He said: 'If you have ADHD and you feel worse in the winter, don't just assume it's your ADHD getting worse - it could actually be SAD.'
American Family Physician (2006) 74: 1,521-1,524.