Seasonal affective disorder can be thought of as a depression which comes about with the winter months where sunlight is less. Its symptoms are; hypersomnia (over sleeping), increased appetite, increased weight gain and profound fatigue (Clark & Kumar, 2002). A possible explanation of the weight gain is that serotonin is thought to be absorbed better with carbohydrates (Lam & Levitan, 2000). So far the pathology of the disease is not quite settled on. There are three options which have been researched in the paper I viewed; the possibility of high melatonin levels, the possibility of a delayed circadian rhythm and the possibility of hypersensitivity to a decrease in light (Lam & Levitan, 2000).

The pineal gland gives us our night and day cycle. It is fed information about light by the retina via the suprachiasmatic nucleus. However, research in which participants were sent to dwell with only artificial light has shown we have a natural rhythm we maintain without light (this would only work in healthy participants of course). These natural rhythms are called circadian rhythms. The suprachiasmatic nucleus produces melatonin which inhibits gonadotrophins from the anterior pituitary which is involved with sexual development. It also produces serotonin which slows down activity at puberty and is often calcified in adults (Waller, 2010).

Different treatments have been used to suit each theory. It has been found that supplementing people with melatonin does not make much difference to their mood. This indicates that using melatonin to cause a negative biofeedback doesn’t work. A negative biofeedback is when the body is given more of something it already has a lot of it reduces those amounts because it can tell there is too much.

Usually SSRI’s (selective serotonin reuptake inhibitors) are given to treat SAD. This is because when there is too much melatonin (the hormone which reacts to light) there is too little serotonin (one of our mood hormones). Therefore, giving an SSRI should raise serotonin and decrease melatonin via a positive feedback. However, the treatment is subject to side effects such as; nausea, anorexia, insomnia, loss of libido and failure to orgasm (Rang, Dale, Ritter, & Flower, 2008).

An alternative treatment is that of phototherapy which provides light of the same frequency to that of natural sunlight. It was found that it was more important that light exposure occurred in the morning between 6-9am than in the evening (Lam & Levitan, 2000). Moreover, it was deemed to be more effective than the use of SSRI’s. The fact that it was more effective in the morning than in the evening supports the delayed or lengthened circadian rhythm hypothesis as well as the sunlight sensitivity hypothesis. One would hope that for the partners of those requiring phototherapy in the morning that it wouldn’t disturb their sleep patterns if they have the correct circadian rhythm but are also sensitive to sunlight as this could create mood disorders in the partner whilst treating the patient!

Gloth, Alan, & Hollis (1999) found that vitamin D was more effective than all the above treatments perhaps indicating a totally different hypothesis for the pathology. More research is needed and I intend to look into vitamin D in the future and post something else about that as well.

Phototherapy is a great natural way to jump start the circadian rhythm of someone with SAD. It is also possible to provide natural SSRI’s in the form of Hypericum perforatum (St. Johns Wort) and Zingiber officianlis (Ginger) (Bone & Mills,2007). Of course these should not be taken along side other SSRI’s and it must always be accounted for that Hypericum interferes with the metabolism (absorption) of products through the gastro-intestinal system. Herbs should never be used along side allopathic medications unless supported by a qualified herbalist. Contact Natasha (our resident herbalist) on our contact us page for more. Below is a picture of Hypericum perf.

Seasonal Affective Disorder

References
Bone, K., and Mills, S. (2007) Principles and Practice of Phytotherapy Modern Herbal Medicine. London: Churchill Livingstone.
Clark and Kumar (2002) Clinical Medicine. London:Elsevier
Lam, R. & Levitan, R. (2000) Pathophysiology of Seasonal Affective Disorder: a review. Journal of Psychiatry and Neuroscience. Vol.25. No.5.
Rang, H., Dale, M., Ritter, J. & Flower, R. (2007) Rang and Dale’s Pharmacology. Philidelpheia: Churchill Livingstone Elsevier.
Waller, P. (2010) Holistic Anatomy,; an integrative guide to the human body. California: North Atlantic Books.