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

Abstract

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.

Colocalized White Matter Plasticity and Increased Cerebral Blood Flow Mediate the Beneficial Effect of Cardiovascular Exercise on Long-Term Motor Learning

“…Based on animal studies showing that short-term exercise interventions are sufficient to trigger gray matter plasticity in motor-related brain areas (Sumiyoshi et al, 2014), we expected similar results in young, healthy adults. However, there are only few studies examining this population to date and, on closer inspection, they reveal an equivocal pattern of results (van der Stouwe et al, 2018). Thus, our results do not fall out of alignment compared with existing evidence.…”

“…Complementary, functional neuroimaging methods like resting-state func-tional MRI (rs-fMRI) and perfusion MRI are used to study changes in brain connectivity and cerebral circulation. Studies using these methods have shown exerciseinduced changes in functional connectivity (Voss et al, 2010;van der Stouwe et al, 2018) and CBF at rest (Maass et al, 2015).…”

The Effects of Exercise on IL-6 Levels and Cognitive Performance in Patients with Schizophrenia

“…In relation to schizophrenia, current studies indicate that exercise can reduce psychiatric symptoms and improve cognitive functions in different subdomains, as reported in the European Psychiatric Association (EPA) guidance [20]. The benefits of exercise for treating this disorder are related to its effects at the level of the brain, and the protective effect produced in the hippocampus by exercise are similar both in patients with schizophrenia and in healthy adults [11] (Figure 1). Several different studies have observed that these changes caused by exercise at the level of the brain improve both the positive and negative symptoms of schizophrenia.…”

“…This is because, when combined with the adequate prescription of other treatments, it has beneficial effects on the immune system. In fact, some studies have already been published that show a reduction in the symptomology of patients with schizophrenia thanks to exercise interventions [11].…”

Neural changes following a body-oriented resilience therapy with elements of kickboxing for individuals with a psychotic disorder: a randomized controlled trial

“…No differences in brain response between the BEATVIC group and the Befriending group following the intervention period were observed with GLM. This could be due to differences between both analysis methods: ICA is more sensitive in detecting task-related changes in fMRI signal than GLM because ICA uses a data-driven approach and can reduce noise in the final solution by separating artifacts from real fMRI signal [41]. With regard to behavioral data of the EF and the WoF task, formal RM ANOVAs also revealed no significant differences in RT and Acc between groups over time.…”