I recently received an email questioning whether mental illness might in whole or in part be related to diet and nutrition.  It is clear to me that the two are intimately related.  Around the turn of the prior century the mental asylums of the southern United States were filled with patients suffering from dementia, melancholy, psychosis and a host of related ailments.  The disease responsible for this malady became known as pellagra.  The prevailing view of the medical profession at this time was that such an epidemic could only be caused by an infectious agent.  It took the knowledge and willpower of Dr. Joseph Goldberger to convince his colleagues that pestilence was not the cause.  He proved that the deficiency of a single nutrient from the diet, niacin (nicotinic acid) in this case, was the causative factor.  To change the mindset of the medical establishment he and his associates held 'filth fests' where they, acting as human guinea pigs, injected themselves with blood and ingested the excreta from patients severely afflicted with pellagra.  Other than for squeamishness in several of the study participants, no symptoms of disease developed over the ensuing six months.  This served to dispel any further investigations into the 'germ' theory of pellagra (niacin, or nicotinic acid, deficiency disease).  Nicotinic acid therapy produced miraculous results.  In spite of this discovery, it still took five years to cure the large number of patients suffering from the disorder.  Part of the problem was the persistence of poor dietary habits.  Poor nutrition remains a major health problem today.

Because of sporadic food fortification, pellagra has become a relic of the past.  However, the broad role of nutrition, and more specifically the impact of prolonged, less severe, dietary deficiencies appears to be playing an increasing role in the production of an array of illnesses.  Mental diseases are no exception.  This is being recognized in the clinic and in the laboratory.  Based on such insights physicians have started recommending dietary interventions alone, or in addition to pharmaceutical treatments to help their patients.  A Harvard-based psychiatrist, Dr. Andrew Stohl, thought one reason responsible for the increase in depressive disorders he was seeing was related to changes in the essential fatty acid content in the modern diet.  There are two essential fats required by the body.  They are the groups of omega 3 and omega 6 fatty acids.  We are consuming much more omega 6 fatty acids than required, and much less omega 3 fat.  Not only is the absolute amount of each class of fats important, their  ratio is also key.  Today we are experiencing an absolute deficiency of the omega 3 fats and a dramatic increase in the omega 6/omega 3 ratio in our diet.  When persistent, these alterations produce inflammation and cause changes in cellular attributes of neuronal function. 

To test his theory, he studied the response to essential fatty acid (EFA) therapy in a group of depressed patients.  Using pharmacological doses of the omega 3 EFAs (meaning about 5-10 times the amount required on a daily basis), he noted a marked improvement in their depressive symptoms.  Additional studies documented improvement in patients with Bipolar Disorder.  He also observed that in a number of his patients he was able to lower the dosage of medication when he incorporated omega 3 EFAs to the treatment regimen.  Obviously this is something that should not be considered without the input of your personal physician.  It does show the power of nutrition to beneficially impact brain function specifically in the arena of mood disorders.

When provided in amounts in excess of the RDI, other nutrients such as folic acid have been shown to beneficially impact depressive symptomatology.  This suggests that they have functional utility beyond their established role in basic metabolic processes. 

Mental illness clearly also has a genetic component, but the clinical phenotype-meaning if, when, and how it expresses itself- is clearly modulated by nutritional factors.  This reasoning even applies in the realm of ADD/ADHD (attention-deficit disorder/attention-deficit-hyperactivity disorder) where symptomatic improvement has coincided with EFA therapy.  This suggests to me there are intimate links between brain function, diet and mental illness and one component in the prevention and/or treatment of these devastating conditions should involve dietary recommendations.