Due to the lack of studies focusing on multisensory and multidomain functioning in schizotypy, we are forced to assume that the benefits of multivariate biomarkers will be as helpful in characterizing those with high schizotypy as it should be in the diagnosed population.
The deficits in SM and WM along the schizophrenia spectrum offer insight into how these previously disparate abnormalities interact and accrue downstream effects. Furthermore, they highlight the value of investigating the use of early-stage sensory interventions for treatment. There is already some evidence of training in SM or WM to alleviate deficits. The effectiveness of sensory training on symptoms has implications for other conditions associated with sensory abnormalities. Assessing biomarkers along the sensory pathway and treating early sensory symptoms is being used in autism (Dinstein et al., 2015; Haigh, 2018; Whitaker et al., 2016)) and in bipolar depression (for a review, see (Sit & Haigh, 2019)). However, it will be important to demonstrate whether these mechanisms are (1) causal, and (2) sensory modality specific.
Comparing SM and WM has the added benefit of identifying biomarkers and neural mechanisms that are unique to schizophrenia symptomatology. For example, schizophrenia is indistinguishable from autism on neuropsychological tests, including WM (Eack et al., 2013). Whereas the schizophrenia population differs from autism in their sensory responses, namely that individuals with schizophrenia typically under-respond whereas individuals with autism tend to over-respond (Haigh et al., 2016; Haigh et al., 2022). Identifying multiple biomarkers associated with schizophrenia and SSD more broadly can help with diagnostic specificity with greater accuracy than single markers.
To improve outcomes associated with schizophrenia, new approaches are needed. We advocate for collecting multiple biomarkers from available, subclinical populations that can collectively monitor symptomsand reveal the mechanisms underlying the symptoms . Alternatively, they may identify treatment successes. With a more complete mechanistic understanding of schizophrenia, such a suite of biomarkers could identify appropriate courses of treatment that will improve long-term outcomes.