The 7th Biennial Schizophrenia International Research Society Conference, Florence, Italy, 6 - 10 April 2022, pp.1-2, (Summary Text)
Background: Growing evidence suggests that early
intervention in psychosis is a promising
paradigm
shift. Its utility may be boosted through more comprehensive strategies for
early
detection
in general populations. Robust evidence has linked baseline psychotic
experiences (PEs)
and general
psychopathology, family history of mental disorders, and some environmental
exposures
(e.g. cannabis use) with increased risk for subsequent psychotic disorders
(PDs).
However,
assessments of incidence of PDs attributable to these ‘markers’ in general
populations is
limited. By
combining prevalence rates and relative risk, these assessments might indeed
open a
new era of
community-based early detection in psychosis. The aim of this study is to
estimate the
population
attributable fraction (PAF) of incident PDs for preceding PEs, mood episodes,
general
psychopathology,
and family history of mental disorders/ cannabis use in a six years follow-up
of a
representative
general population
Methods: A community-based sample, representative of
the urban and rural population of a
metropolitan
city (n: 2185) was visited twice at their households (baseline and sixth year
follow-up
assessments).
PEs, mood episodes, general psychopathology, cannabis and alcohol use was
evaluated
using Composite International Diagnostic Interview 1.2. PEs were categorized
into clinical
PEs
(associated with distress or help-seeking or frequent) and subclinical PEs.
Family history of
mental
disorders was assessed using questions derived from the Family Interview for
Genetic
Studies.
Participants with probable PDs were re-interviewed with the SCID-I by team
psychiatrists at
both
assessments. PAF analyses were performed adjusting for age, gender and
education
Results: The incidence rate of PDs was 21.8 per 100,000
person-years. Of the PDs incidence in the
general
population, 62.2% (%95 CI: %32.0-78.9) was attributable to help seeking for any
mental
disorders
at baseline. Only half of the PDs incidence was attributable to baseline PEs
(PAF: 53.3;
95% CI:
%22.8-71.4) at any severity (including clinical and subclinical PEs).
Interestingly, PAFs of
PDs
incidence for baseline clinical PEs and baseline mood episodes were similar
(PAFs respectively;
41.1,
95%CI: 17.5-58.6 and 39.3, 95%CI:12.1-58.1). Furthermore, the PAFs of PDs
incidence for any
family
history of mental disorders (37.0, %95CI: 8.7- 56.5) and cannabis use (PAF:
26.6, %95 CI:
%7.2-41.9)
were also high.
Discussion: These results highlight the importance of
different pathways through psychotic
disorders
outside the ‘exacerbation of positive symptoms’ pathway. Assessments of
multiple
dimensions
of psychopathology next to subthreshold positive domain may be more effective
for