No longer seen that often in the 21st century, but back when I was young, we were the last of many generations being told not to use our left-hands to write, whether it was due to culture, religion, or “because mummy said so”. Even though there are positive characteristics attributed to left-handedness such as it being linked to wisdom, left-hand in Latin is known as “sinistral” with its English derivative being sinister, while in the Chinese tradition, left-hand usually gets linked to “improper”.
As the left side of the brain favours logical, rational, analytical and objective thinking; the right side of the brain goes for intuitive, subjective, beliefs, and spatial perception. We know that the right side of the brain controls muscles on the left side of the body and the left side of the brain controls muscles on the right side of the body, thus left-hand = right brain.
Subjectivity and perception is a major challenge for patients with mental illness as the biggest fear for all of us is the fear of the unknown. A meta-analysis in 2001 found that left and mixed handed subjects may be at increased risk of schizophrenia, and strong evidence indicating decreased cerebral lateralisation (specialisation of the hemispheres) in schizophrenic patients. It is also noteworthy that psychiatric hospital stays are longer for, and more strongly associated, with left-handers.
In 2003, mental illnesses were among the ten leading causes of disease burden in Australia, accounting for 13% of the total burden of disease. These illnesses not only lead to high levels or morbidity and mortality, but they significantly impact families, carers and other people in the community.
The aim of having a balanced life is achieved with outcomes outlined by the Mental Health Commission of Western Australia, from health, wellbeing and recovery, all the way through to having a sense of community belonging. General exercise, which stimulates both sides of the brain contributes to this balance and has been shown to produce antidepressant effects, especially when the exercise training program is longer than nine weeks and involves more sessions.
Handedness is a result of genetic expression. A recent study has shown that the five common mental disorders: schizophrenia, bipolar disorder, autism, major depression and Attention Deficit Hyperactivity Disorder (ADHD) are pointing towards a commonality at the biological/genetic level. The fact that genes only express when they are signalled, by external or internal factors, further emphasises that lifestyle, including diet, does play a significant role.
Dietary consumption is important for patients with mental illness. A “balanced meal” is important for a healthy body and mind. A diet high in sugar and high in saturated fat is associated with a poor two year outcome for schizophrenia.
Supplementations such as cholecalciferol (vitamin D) is also important in patients with mental illness as there have been studies showing adolescents with vitamin D levels below 20ng/ml presenting for hospital treatment of acute mental illness were four times more prevalent than adolescents with normal vitamin D levels (greater than 30ng/ml). There is also recent evidence suggesting that fish intake may have positive effects on psychotic-type symptoms.
Based on the facts above, health professionals should move forward together to improve the patient’s condition by finding the right balance, no matter if they are “right” or “left”, and even if there may be a genetic predisposition for mental illness.
All mental health patients should be provided full counselling on their medications and also be given recommendations about their pharmacotherapy to find their particular balance, instead of being dictated to by their medications due to health illiteracy, or trying to following an over-strict schedule based on their pharmacotherapy which may lead to non-adherence.
Advice should include the proven interactivity of herbal supplements with medications used in mental illness. Examples are: St John’s Wort interacting with SSRIs (selective serotonin reuptake inhibitors) and SNRIs (serotonin-noradrenaline reuptake inhibitors), and kava and chamomile (Matricaria recutita) having benzodiazepine like effects.
Assist patients to seek help from organisations such as Beyond Blue, or give important phone numbers that they can hold on to such as the one for Lifeline (13 11 44), and provide support each time the patient visits as a good start in their ongoing battle with mental illness.
- Australian Institute of Health and Welfare. Australia’s Health 2006. Australia’s Health no. 10. Cat. no. AUS 73. Canberra: AIHW; 2006.
- Chudler EH. One Brain… or Two? Seattle: Neuroscience for Kids; 2010. Available from http://faculty.washington.edu/chudler/split.html. Accessed 28 January 2011.
- Sommer I, Ramsey N, Kahn R, Aleman A, Bouma A. Handedness, language lateralisation and anatomical asymmetry in schizophrenia: meta-analysis. Br J Psychiatry 2001; 178: 344-51.
- Mirabile CS Jr, Teicher MH. Hand preference and length of psychiatric hospital stay by month of admission [abstract]. Percept Mot Skills 2002 Dec; 95(3 Pt 1): 835-6.
- North TC, McCullagh P, Tran ZV. Effect of exercise on depression. Exerc Sport Sci Rev 1990; 18: 379-415.
- Simopoulos AP(ed.). Nutrition and Fitness: Mental health, aging, and the implementation of a healthy diet and physical activity lifestyle. Part 2. Washington: Karger Publishing; 2005, p.20-22.
- Zoler ML. Low Vitamin D Linked to Psychosis in Teens. Family Practice News 2010; 40 (20): p.62.
- Hedelin M, Löf M, Olsson M, Lewander T, Nilsson B, Hultman CM, Weiderpass E. Dietary intake of fish, omega-3, omega-6 polyunsaturated fatty acids and vitamin D and the prevalence of psychotic-type symptoms in a cohort of 33,000 women from the general population. BMC Psychiatry 2010 May 26; 10: 38.
- Mental Health Commission. Mental Health Outcome Statements. Perth: Government of Western Australia; 2010.
- Cross-Disorder Group of the Psychiatric Genomics Consortium, Smoller JW, Craddock N, Kendler K, Lee PH, Neale BM, Nurnberger JI et al. Identification of risk loci with shared effects on five major psychiatric disorders: a genome-wide analysis. Lancet 2013; 381(9875): 1371-9.