i dont believe its about the colder climate as much as i do believe it is about vitamin d and serotonin to your brain. ive lived in maine for my whole life except for the years i lived in the florida keys. major difference in mood and Depression when the sun starts setting at 4:20 instead of 8:00 i noticed. even with plenty of outdoor winter activities sometimes the sun just isnt in the right place to help our troubled minds.