The chemical mechanism of depression remains controversial. For decades, psychiatrists have been telling us that a deficiency of monoamine neurotransmitters, usually serotonin, causes depression. But what causes that deficiency? And why do different patients have such different responses to antidepressant drugs?
There is another theory in the medical literature. Inflammation is strongly associated with depressive symptoms. It is well known that autoimmune diseases can damage almost any tissue or organ with an excessive inflammatory response to triggers that may or may not be identified. Some researchers report that inflammatory cytokines may be the true chemical imbalance for at least some depressed patients. Thus, anti-inflammatories have potential to be more effective than conventional antidepressants in some or all cases. There are many types of drugs currently used to reduce the immune system's attack on healthy tissue, with varying degrees of success for most autoimmune and inflammatory conditions.
I found three clinical trials currently in progress for immune therapies for depression. Two are dietary supplements and two are prescription drugs:
Vitamin D. This option is immediately available to anyone who wants to try it. Researchers at Loyola University in Maywood, Illinois, are testing dietary supplement capsules containing 50,000 IU of vitamin D once a week for six months to improve metabolic control and treat depressive symptoms in women with type 2 diabetes. Vitamin D has been associated with protection from multiple sclerosis, an autoimmune condition that affects the nervous system.
Omega-3 fatty acids. This is another nutritional option, under investigation by the University of Cincinnati. The dosages are 2.4 g/day and 15 g/day.
Cimicoxib. Affectis Pharmaceuticals is developing this non-steroidal anti-inflammatory drug (NSAID) for the treatment of depression and schizophrenia. It selectively inhibits the action of COX-2. This means it is similar to other drugs such as celecoxib (Celebrex). However, the manufacturer reports that their new drug is better absorbed into the brain, and has demonstrated antidepressant effects in animal models.
Infliximab (Remicade). This drug is already used for the treatment of inflammatory conditions such as Crohn's disease and rheumatoid arthritis. It is a tumor necrosis factor alpha inhibitor. Emory University in Atlanta, Georgia is sponsoring the trial for treatment of depression.
More information is available online in the references.
References:
1. Dantzer R et al, “From inflammation to sickness and depression: when the immune system subjugates that brain”, Nat Ref Neurosci. 2008 Jan; 9(1): 46-56.
2. Vitamin D clinical trial:
http://clinicaltrials.gov/ct2/show/NCT01185574?term=depressive+vitamin+D&rank=1
3. Omega-3 fatty acids clinical trial:
http://clinicaltrials.gov/ct2/show/NCT00511810?term=depressive+inflammation&rank=18
4. Vitamin D and omega-3 fatty acids in multiple sclerosis:
https://www.empowher.com/multiple-sclerosis/content/nutrition-autoimmune-conditions
5. Cimicoxib information:
http://www.affectis.com/pipeline/cimicoxib
6. Infliximab trial:
http://clinicaltrials.gov/ct2/show/NCT00463580?term=depressive+infliximab&rank=1
Linda Fugate is a scientist and writer in Austin, Texas. She has a Ph.D. in Physics and an M.S. in Macromolecular Science and Engineering. Her background includes academic and industrial research in materials science. She currently writes song lyrics and health articles.