The National Institute of Mental Health estimates that 26.2 percent of U.S. adults ages 18 and older suffer from a diagnosable mental health disorder each year, with almost half who suffer from two or more disorders. Psychiatrists use the Diagnostic and Statistical Manual of Mental Disorders, fourth edition, also known as the DSM-IV, to diagnose anxiety, mood, eating, attention deficit hyperactivity, autism, personality and other disorders. Mental health disorders have some biological causes.
Genetics
In a landmark research study, Ronald Kessler, Ph.D., and colleagues at Harvard Medical School discovered that half of all lifetime cases of mental health disorders start by age 14 and three-fourths start by age 24. This study reveals that unlike most physical diseases, mental health disorders begin in youth and continue throughout life. Nonetheless, long delays between onset of symptoms and treatment are common.
Genes and environmental factors play a role in the onset, severity and progression of mental health disorders. Defects in the interaction of multiple genes can increase the risk for disorders. Although the specific genes involved are unknown, heritability studies on prevalence of disorders within families support the genetic cause. Scientists at Ben Gurion University of the Negev in Israel discovered that there is a high prevalence of mental health disorders in parents of severely dysfunctional families compared with well-functioning families, 43.2 percent versus 6.6 percent. The prevalence is even greater among children, 56.6 percent versus 3.8 percent.
Nutrition
L-tyrosine, l-tryptophan and l-glutamic acid are amino acids found in most protein foods that produce the neurotransmitters dopamine, serotonin and GABA, respectively, in the brain. Alterations of plasma levels of these dietary amino acids can contribute to deficiencies in the production of neurotransmitters associated with depression, eating disorders, anxiety and other mental health disorders. Diets high in protein and low in carbohydrate can inhibit these amino acids from transporting across the blood brain barrier and cause reduced neurotransmitter production.
Vitamin B6 is essential for the production of neurotransmitters. According to scientists at the University of Manitoba in Canada, low serotonin levels in various areas of the brain are associated with vitamin B6 deficiency. Scientists at Cochin University of Science and Technology in India discovered that dietary deficiencies of vitamin B6 can affect the ability of neurotransmitters to bind to receptors on nerve cells, increasing risk for mental health disorders.
Infections
According to the National Institute of Mental Health, infectious agents can penetrate the brain and cause mental health disorders. Examples of these cases include syphilis and psychosis, HIV and dementia, and streptococcal pharyngitis and obsessive compulsive disorder in children; this latter disorder is now called PANDA, which stands for pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection. Tumor viruses such as hepatitis B virus, hepatitis C virus, T-cell leukemia virus, Epstein-Barr virus and human papilloma virus, can also cause cancer and affect the onset of mental health disorders. Research scientists at Yale University found that patients with advanced cancer experience major psychiatric disorders at a prevalence similar to the general population.
References
- "Archives of General Psychiatry"; Lifetime Prevalence and Age-of-Onset Distributions; Kessler, R.C.; Jun 2005
- "Harefuah"; Mental Disorders in Severely Dysfunctional Families; Ben-Noun, L.; May 1989
- "Journal of Neuroscience Research"; Effect of Pyridoxine Deficiency on Serotonin Dopamine Receptors; Paulose, C.S.; 1985
- National Institute of Mental Health: Mental Health: A Report by the Surgeon General
- "Cancer"; Psychiatric Disorders in Patients with Advanced Cancer; Kadan-Lottick; Dec 2005
