Neural correlates of exercise training in individuals with schizophrenia and in healthy individuals: A systematic review

• Published in: NeuroImage clinical 2018-01, Vol.19, p.287-301
• Main Authors: van der Stouwe, E.C.D., van Busschbach, J.T., de Vries, B., Cahn, W., Aleman, A., Pijnenborg, G.H.M.
• Format: Article
• Language: English
• Subjects: Brain - diagnostic imaging; Exercise; Exercise - physiology; Hippocampus; Humans; Magnetic Resonance Imaging; Magnetic resonance imaging (MRI); Neuroimaging; Physical activity; Regular; Schizophrenia - diagnostic imaging; Schizophrenia spectrum disorder; White Matter - diagnostic imaging
• ISSN: 2213-1582; 2213-1582
• DOI: 10.1016/j.nicl.2018.04.018

A body of evidence has revealed positive effects of physical exercise on behavioral, cognitive and physical outcomes in patients with schizophrenia. Notably, the effect of exercise at the neural level may be particularly relevant as well as it is hypothesized that exercise may stimulate the brain in a way that might normalize neural alterations related to the disorder. The aim of the current systematic review was to provide an up to date overview of studies investigating the neural effects of exercise in individuals with a schizophrenia spectrum disorder and healthy individuals. The majority of included studies focused on hippocampal effects, reporting beneficial effects of exercise. In addition, in schizophrenia increased extrastriate body area (EBA) activation and increased white matter fiber integrity in tracts relevant to the disorder were found and in healthy individuals decreased connectivity of the dorsolateral prefrontal cortex (DLPFC) indicating greater cognitive efficiency was reported. Comparing individuals with a schizophrenia spectrum disorder and healthy individuals within a similar age range, most studies found similar effects on hippocampal volume and white matter tracts for both groups, although the effect in schizophrenia spectrum disorders may be attenuated which is in line with previous literature on brain plasticity. The current review indicates a lack of studies investigating neural correlates other than the hippocampus. Although those studies that did focus on other neural correlates revealed promising results, these have not been replicated in other studies and call for replication. Furthermore, future studies should expand their focus, by investigating neural mechanisms underlying positive effects of physical exercise on positive symptoms, negative symptoms and symptoms such as depression, social withdrawal and social cognition. •MRI studies on exercise found positive effects on the hippocampus post training in schizophrenia spectrum disorders and controls.•Positive effects were also found in the EBA and in white matter tracts in schizophrenia spectrum disorders.•Positive effects were also found in DLPFC connectivity in healthy individuals.•Effects in schizophrenia may be attenuated.•There seems to be a dose-response relationship between exercise and neural effects.