Understanding the potential mechanisms of disease modifying effects of physical activity and exercise in people with schizophrenia.

Schizophrenia is a serious chronic mental health problem that usually starts during adolescence and early childhood. It is characterized by positive symptoms (delusions, hallucinations and grossly disorganized speech and behaviour), negative symptoms (apathy, isolation and diminished affect), and cognitive impairment that negatively affect quality of life. Its treatments include the use of pharmacological interventions, exercise, non-invasive brain stimulation and cognitive remediation training. Exercise is a very simple and cost-effective intervention. However, it is important the mechanisms of its effects are understood so that it can be trusted in clinical practice. In addition, understanding the mechanisms is important for its modification and safe use. Similarly, it may help provide the basis for invention of safe and cost-effective pharmacological or alternative therapies. From the literature, the mechanisms of diseases modifying effects of exercise seem to include increased cardiorespiratory fitness, biochemical changes (increased level of BDNF, increased N-acetylaspartate (NAA)/cr (creatine) ratio, decreased level of triglycerides, increased high density lipoprotein (HDL) and decreased salivary cortisol), structural changes (increase in cerebral volume, increased white matter integrity and increased cortical thickness) and anthropometric changes (reduced body weight and body mass index (BMI), increased muscular strength and decreased waist-hip ratio or waist circumference or hip circumference).