Hello there, the answer is definitely.
SAD is a reaction of adrenal gland, when there is less sunshine your mood changes. Reflexology is helpful to work on the hormonal glands and will help balance the hormonal secretions in your body.
You will feel better.
But hey if you want Reflexology you cannot have just one session.. you gotta have 4 or 5 sessions, then see how you feel.
Another very good (and simpler) remedy for SAD is those lamps. You shine that lamp at yourself for 20 mins a day and your body thinks it's like sunshine and produce the right hormones again.
See here: http://www.google.co.uk/search?hl=en&q=SAD+lamp&btnG=Search&meta=
Good luck this winter !