I am BD1, but for me, the sun has an enormous affect upon me.
As soon as the first week of November arrives, no matter what, I plummet into depression. That week is when our (Calif.) temperatures drop and the sunlight is low. Horrible anxiety and depression and mixed states. Med increases. Med changes. I'm at my mental health clinic they might as well give me my own room.
With the first bit of spring in March my mood stabilizes; by later spring I feel manic-y. Summer can get intense. If I was not on meds, I know the entire cycle would be far more intense.
Even now, with the dreariness of COVID I feel much more energized and jumpy.
Anyway, my point is that I am very much affected by the sunlight. I have come to dread fall and winter.
__________________
|