Q2. What is the main advantage of the PRS approach?
One of the main advantages of the PRS approach is the ability to study how genetic risk for schizophrenia is manifest across the general population, and during different stages of development.
Q3. What is the significance of the SZ-PRS?
Future increases in size of discovery samples may also enable PRSs to make a meaningful contribution to risk prediction models, as has been shown for some non-psychiatric disorders (Chatterjee et al. 2016).
Q4. What was the common symptom of adolescence?
The population-based Longitudinal Experiences and Perceptions (LEAP) study found that SZPRS was associated with decreased anhedonia (strongest PT<0.5; one-tailed p=0.003) and parent-rated negative symptoms in adolescence (one-tailed p=0.029) (Sieradzka et al. 2014).
Q5. What is the main advantage of the SZ-PRS approach?
The SZ-PRS was consistently associated with poorer cognition in population-based studies and from childhood through to older age (McIntosh et al. 2013; Hubbard et al. 2016).
Q6. What was the common symptom dimension in the Dutch case-control study?
In the Netherlands case-control study of schizophrenia, SZ-PRS was associated with five symptom dimensions (strongest PT<0.5): positive (p=<0.01), negative (p= <0.001), mania (p= <0.01), depression (p= <0.001) and disorganisation (p=0.04) within the combined casecontrol sample, but not with these dimensions in cases and controls examined separately (Derks et al. 2012).
Q7. What was the reason for the inconsistency of the results?
the inconsistency of reporting of results across studies meant that only a narrative approach to this review was feasible, and assessment of publication bias was not possible.
Q8. What other outcomes were associated with the SZ-PRS?
The SZ-PRS was also associated with a number of other, non-psychiatric outcomes, including diabetes, RA and CD (Stringer et al. 2014), though results were not consistent across studies.
Q9. What is the association between SZ-PRS and adolescent negative symptoms?
Higher SZ-PRS was associated with lower total IQ in a combined schizophrenia case–control sample (strongest PT<0.3, p=8x10-4), but this was attenuated when analysing cases only (p=0.067), with no association in controls (van Scheltinga et al. 2013).