Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Nov 16;21(1):574.
doi: 10.1186/s12888-021-03498-3.

Testing extra-linearity across a psychosis continuum

Jeremy W Coid #  1 , Yamin Zhang #  1 , Jinkun Zeng  1 , Xiaojing Li  1 , Qiuyue Lv  1 , Wanjie Tang  2   3 , Qiang Wang  1 , Wei Deng  1   4 , Wanjun Guo  1 , Liansheng Zhao  1 , Xiaohong Ma  1 , Yajing Meng  1 , Mingli Li  1 , Huiyao Wang  1 , Ting Chen  1 , Min Yang  5   6 , Tao Li  7   8
Affiliations

Testing extra-linearity across a psychosis continuum

Jeremy W Coid et al. BMC Psychiatry. .

Abstract

Background: It is unclear whether psychotic experiences (PEs) gradually merge into states of clinical psychosis along a continuum which correspond to a dimensional classification or whether latent classes appear above a certain severity threshold which correspond better to diagnostic categories of psychosis.

Methods: Annual cross-sectional surveys, 2014-19, among Chinese undergraduates (N = 47,004) measured PEs, depression and etiological risk factors using standardized self-report instruments. We created a psychosis continuum with five levels and tested linear and extra-linear contrasts in associated etiological risk factors, before and after adjustment for depression. We carried out latent class analysis.

Results: Categorical expression of psychosis, including hallucinations and delusions, nuclear symptoms, and nuclear symptoms and depression were found at severe level 5. Etiological risk factors which impacted linearly across the continuum were more common for depression. Child maltreatment impacted extra-linearly on both psychosis and depression. Family history of psychosis impacted linearly on psychosis; male sex and urban birth impacted extra-linearly and were specific for psychosis. Four latent classes were found, but only at level 5. These corresponded to nuclear schizophrenia symptoms, nuclear schizophrenia and depressive symptoms, severe depression, and an unclassified category with moderate prevalence of PEs.

Conclusion: Quantitative and qualitative changes in the underlying structure of psychosis were observed at the most severe level along a psychosis continuum, where four latent classes emerged. These corresponded to existing categorical classifications but require confirmation with clinical interview. PEs are non-specific and our findings suggest some are on a continuum with depression, whilst others are on a continuum with non-affective psychosis. Differing patterns of impact from etiological risk factors across the spectrum of psychopathology determine outcome at the most severe level of these continua.

Keywords: Etiology; Extra-linearity; Psychosis continuum; Psychosis subtypes; Psychotic experiences.

PubMed Disclaimer

Conflict of interest statement

There are no Competing interests.

Figures

Fig. 1
Fig. 1
.ᅟ
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

References

    1. van Os J, Linscott RJ, Myin-Germeys I, Delespaul P, Krabbendam L. A systematic review and meta-analysis of the psychosis continuum: evidence for a psychosis proneness-persistence-impairment model of psychotic disorder. Psychol Med. 2009;39(2):179–195. doi: 10.1017/S0033291708003814. - DOI - PubMed
    1. Binbay T, Drukker M, Elbi H, Tanik FA, Ozkinay F, Onay H, Zagli N, van Os J, Alptekin K. Testing the psychosis continuum: differential impact of genetic and nongenetic risk factors and comorbid psychopathology across the entire spectrum of psychosis. Schizophr Bull. 2012;38(5):992–1002. doi: 10.1093/schbul/sbr003. - DOI - PMC - PubMed
    1. van Os J, Verdoux H. The Epidemiology of Schizophrenia. Cambridge: Cambridge University Press; 2003. Diagnosis and classification of schizophrenia: categories versus dimensions, distributions versus disease; pp. 364–410.
    1. Claridge G. Single indicator of risk for schizophrenia: probable fact or likely myth? Schizophr Bull. 1994;20(1):151–168. doi: 10.1093/schbul/20.1.151. - DOI - PubMed
    1. Johns LC, van Os J. The continuity of psychotic experiences in the general population. Clin Psychol Rev. 2001;21(8):1125–1141. doi: 10.1016/S0272-7358(01)00103-9. - DOI - PubMed

Publication types