The neuromuscular basis of functional impairment in schizophrenia: A scoping review

Patients with schizophrenia exhibit functional impairments in their locomotory tasks, which decreases their quality of life. Due to the limited current research, the neuromuscular mechanisms behind the functional impairments in patients is not fully understood. Thus, this review aims to summarize the neuromuscular mechanisms that underlie these deficits in daily functioning. These deficits are speculated to stem from abnormalities at various levels from neurons through to the skeletal muscles. The neurological abnormalities are exhibited as lower motor neuron dysfunction whereas the skeletal muscle pathology is shown as increased muscle fibre (type 1 and type 2) atrophy, reduction in maximal force generation, and increased strength loss per decade. Although antipsychotics effectively reduce positive symptoms, functional impairments remain unresolved. Both endurance and resistance training have shown potential benefits in alleviating deficits in daily functioning by increasing muscular strength, increasing fat-free mass, and preserving neuromuscular properties from degradation. In summary, the review elucidates various possible mechanisms for the onset of functional impairment experienced by patients with schizophrenia and highlights the potential utility of endurance and resistance training to alleviate these deficits in daily functioning.