Thanks for the great post on s.a.d.I have had it for a number of years and only resently found out why it happens,but did'nt know of some of the remedies.Mine seems to have gotten better over the last few years,but its still there.Mine seams to last no more then a month,i think the best thing to do is stay busy,and be around friends and family more.I have also heard of this gland at the base of the bottom back side of the neck,peanil gland ,ok im sure my spelling is'nt correct but it sounds something like that,anyway if that gland does'nt get enough lite then one could possibly get depressed or just not feel 100%.Hope this helps in some small way,Dave.