I also find myself going into hibernation mode in autumn. My metabolic rate, always low, falls further and if I don't wear gloves my skin cracks. I'd like to mention a few things - first vitamin D. Dr Sasha Gominak (a neurologist) says you need to keep this within a certain band for restful sleep. http://drgominak.com/vitamin-d-3/ So over-supplementation wouldn't produce greater gains. I had my levels measured, they were low (at the end of summer and after supplementing with 400 iu), I supplemented with 2000 iu overwinter and date a slow recovery from being practically bedbound to being able to do a little to the supplementation. I also eat a lot of oily fish, a good source of vitamin D. I've just gone back to supplementation after stopping for the summer and will take at least 1000iu per day. I'm considering a UVB sun lamp like this http://www.amazon.com/KBD-Vitamin-D-Lite-Flourescent/dp/B004GYB6X6/ref=pd_sim_sbs_hpc_4/190-3535071-8511601 although I'd have to have the expensive uk version http://www.phbhealthcare.com/uvb/ but as we age the skin becomes less effective at producing vitamin D and I'm no youngster Secondly there is a theory that hydrogen sulphide gas is an issue in ME http://www.cortjohnson.org/blog/2013/10/10/atp-hydrogen-sulfide-natural-killer-cells-heart-mecfs-associations-video-series-back/ If anyone knows where to get DL-propargylglycine I'd try that but as it is I'm working on trying to change my gut flora, as that may reduce hydrogen sulphide. Could diet changes affect while we feel worse in autumn? I know that in summer I eat a lot more fruit, it's been a good apple year in England so I'm still eating a lot and not feeling as bad as usual. I've also tried the "better on holiday" route and it does help me a little but that could be that I don't have the energy to keep my home dust free.