From my annual review of articles from psychiatry journals, here is the first of a few which caught my eye: they're very simple studies looking at medication augmentations.
An augmentation refers to adding some type of therapeutic agent (usually a medication) to help make another therapeutic modality work better. Usually an augmentation would not be expected to help much on its own--the term implies that it must be used with something else. Typical augmentations in common use are triiodothyronine (a form of thyroid hormone) or lithium added to antidepressants to treat depression.
It's always nice to see an article which has an extremely simple premise (e.g. to try some new therapy or other), which could be readily applied in an attempt to help someone immediately.
The first article is from a Korean group (Lyoo et al.) published in the American Journal of Psychiatry in September 2012. ( http://www.ncbi.nlm.nih.gov/pubmed/22864465 ) They looked at treating 52 women having a major depressive episode, with either escitalopram 10-20 mg/day plus placebo, or escitalopram 10-20 mg plus 5 grams of creatine monohydrate daily.
From the second week of treatment onwards, the creatine group had better symptom improvement. After 8 weeks, over 50% of the creatine group met criteria for remission, compared to only about 25% of the placebo group.
Creatine has been used for years as a type of muscle-building supplement. It may have some benefits for various neuromuscular and other neurological disorders. Risks and side-effects are minimal, according to my reading of existing evidence, particularly at doses of 5 grams per day or less (see this risk assessment review: http://www.ncbi.nlm.nih.gov/pubmed/16814437 ). In the brain, the mechanism is of improving ATP availability, thereby improving cellular energy dynamics. Humans obtain creatine from the diet (about 1 g/day) and from synthesis inside the body (another 1 g/day). So it makes sense to have therapeutic doses well above the body's baseline supply of 2 g/day. Here is a reference to an excellent review article by Persky (2001 http://www.ncbi.nlm.nih.gov/pubmed/11356982
Creatine is readily available wherever one would obtain nutritional supplements. If one were to try creatine, I might suggest looking for pure creatine monohydrate, as opposed to some mixture (typically with protein powder), as the mixture would be more expensive, and would often contain unnecessary additives such as artificial sweeteners. The creatine could be ingested as a partially dissolved suspension in warm water or juice. The dosing regime could be debated somewhat, as creatine has quite a short half-life in plasma. This current study used a single large dose daily, but the idea of using divided dosing should be explored.