There is evidence that dopamine plays an important role in Seasonal Affective Disorder (SAD) (Depue et al, 1990; Arbisi et al, 1994; Neumeister et al, 2001; Lam et al, 2001). So, it stands to reason that increasing dopamine levels in natural ways might help with Seasonal Affective Disorder. I have found this to be very true in my own personal experience.
It never made sense to me that the depression and restlessness that would strike me on cloudy days and during the winter months was due only to the reduced sunlight. If that were true, why didn't I feel depressed every evening when the sun went down? Nevertheless, I tried the special lights designed to help people with SAD, sitting in front of them as much as I could stand it. I even bought one that attached to the top of my computer screen to shine on me while I worked. Despite my best efforts, they didn't really help me.
I'll tell you what has helped me though! It is a system I am developing for raising dopamine levels naturally, and I'm it calling "Pleasure Power". I am using natural ways such as thought management and mental focus techniques, music, and sensory stimulation to increase my dopamine levels, and it is really working for me. Not only do I feel really good and not depressed at all, even on the cloudiest winter days, but I am losing weight instead of gaining weight this winter!
Dopamine is a neurochemical which is released every time we feel pleasure of any kind. It reduces appetite, increases energy, increases focus, heightens physical senses, increases our ability to feel pleasure, and gives us a youthful, happy, healthy, and sometimes even euphoric feeling. It makes sense to me that my dopamine levels may decrease on cloudy days and during the winter months, simply because there is less visual pleasure. On bright sunny days, everything looks pretty. There are lots of colors to look at, and even beautiful sparkles from the sun on the leaves and the water. That pleasure causes a rise in dopamine levels, which I think is why I feel so much better on bright sunny days.
I think it is possible to compensate for the lack of visual pleasure on cloudy days, and to achieve good dopamine levels from other sources of pleasure. For example, I have found that my favorite way to increase my dopamine levels naturally is to put on headphones and listen to Pandora Internet Radio with my $5/month plan for unlimited skips. I skip songs until I find the ones I really, really love. Then, I focus all of my attention on those songs and the pleasure they give me. From there, I begin to spread my focus to any other physical sensation which might be giving me pleasure, such as the smell of the ocean air, or the breeze on my skin, or how good it feels to move my body to the beat of the music. The more physical pleasure I experience, and the more I focus on the pleasure, the more I feel my dopamine levels rising.
Arbisi PA, Depue RA, Krauss S, Spoont MR, Leon A, Ainsworth B et al (1994). Heat-loss response to a thermal challenge seasonal affective disorder. Psychiatry Res 52: 199–214.
Depue RA, Arbisi P, Krauss S, Iacono WG, Leon A, Muir R et al (1990). Seasonal independence of low prolactin concentration and high spontaneous eye blink rates in unipolar and bipolar II seasonal affective disorder. Arch Gen Psychiatry 47: 356–364.
Lam RW, Tam EM, Grewal A, Yatham LN (2001). Effects of alphamethyl-para-tyrosine-induced catecholamine depletion in patients with seasonal affective disorder in summer remission. Neuropsychopharmacology 25(Suppl): S97–101.