Anomalous self-experience in substance-induced and primary psychotic disorders: a cross-sectional comparative study using the EASE interview.
Luisa de Risio, Alessio Mosca, Arianna Pasino, Enrico Pompili, Giuseppe Nicolò, Mauro Pettorruso, Giovanni Martinotti
Annals of General Psychiatry November 25, 2025 DOI: 10.1186/s12991-025-00608-3 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Cross-sectional comparative study Longitudinal Peer reviewed |
|---|---|
| Sample size | 54 |
| Population | Clinically stable patients with schizophrenia spectrum disorders or substance-induced psychosis |
| Topics | Philosophy of mind |
| Keywords | Ease Minimal self Schizophrenia Self-disorders Substance-induced psychosis |
| Key findings | Anomalous self-experiences are present in both primary psychotic disorders and substance-induced psychosis, with self-world boundary disturbances being more prominent in substance-induced psychosis. |
Abstract
Disturbances of the minimal self, or anomalous self-experiences (ASEs), are increasingly regarded as a core feature of primary psychotic disorders (PPDs). However, it remains unclear whether similar self-disorders are present in substance-induced psychosis (SIP), a condition that often mimics PPDs in its early stages. The study aims to compare ASEs between PPD and SIP using the EASE interview, to evaluate the diagnostic specificity of ASEs and determine whether these disturbances are exclusive to primary psychoses or also present in SIP. A total of 54 clinically stable patients were recruited from psychiatric centers in Italy (27 with schizophrenia spectrum disorders (SSD), mean age ≈ 27 years; 27 with substance-induced psychosis, mean age ≈ 28 years).. Diagnoses were established according to DSM-5 criteria. ASEs were assessed using the Examination of Anomalous Self-Experience (EASE) interview, and scores were compared across five experiential domains. Non-parametric statistics and logistic regression were employed to identify domain-specific differences and their diagnostic utility. While total EASE scores did not differ significantly between groups, Domain 4 (Demarcation/Transitivism) was significantly higher in the SIP group (p < .0001, r = .72), contrary to classical phenomenological models that typically associate self-world boundary disturbances with schizophrenia spectrum disorders. In contrast, Domain 2 (Self-awareness and Presence) trended higher in the PPD group (p = .049, r = .27) and Domain 5 (Existential Reorientation) showed a similar trend (p = .098, r = .22)., aligning with classical phenomenological models of schizophrenia. Logistic regression confirmed the predictive value of these domains for group classification. ASEs are not exclusive to PPDs and may also manifest in SIP, particularly in the domain of "self-world boundary" disturbances. These findings challenge the assumption that self-disorders are unique to endogenous psychosis and highlight the need for refined phenomenological assessment in early diagnostic work. Longitudinal studies are needed to clarify whether ASEs in SIP represent transient phenomena or prodromal markers of schizophrenia.
Comparable studies
Other cross-sectional and survey studies on philosophy of mind, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Survey of entity encounter experiences occasioned by inhaled N,N-dimethyltryptamine: Phenomenology, interpretation, and enduring effects. People who had a memorable entity encounter after taking N,N-dimethyltryptamine | 2020 | Survey | n = 2,561 |
| Future directions in meditation research: Recommendations for expanding the field of contemplative science Meditators | 2018 | Cross-sectional online survey | n = 1,120 |
| The Phenomenology of Lucid Dreaming: An Online Survey Respondents to an online survey about lucid dreams | 2014 | Online survey | n = 684 |
| The neurophenomenology of early psychosis: An integrative empirical study. Ultra-high risk for psychosis patients, first episode psychosis patients, and healthy... | 2019 | Cross-sectional | n = 123 |
| Spontaneous Spiritual Awakenings: Phenomenology, Altered States, Individual Differences, and Well-Being People reporting their most powerful Spontaneous Spiritual or Kundalini Awakening | 2021 | Mixed within and between-participants self-report survey design | n = 152 |
Citations in the library
Cites 7
- Substance-related exogenous psychosis: a postmodern syndrome CNS Spectrums June 25, 2020
- Disordered Selfhood in Schizophrenia and the Examination of Anomalous Self-Experience: Accumulated Evidence and Experience. Psychopathology 2021
- Towards a Neurophenomenological Understanding of Self-Disorder in Schizophrenia Spectrum Disorders: A Systematic Review and Synthesis of Anatomical, Physiological, and Neurocognitive Findings Brain Sciences May 23, 2023
- Danilo Cargnello and his contribution to the development of phenomenological thought: an overview. History of Psychiatry December 1, 2023
- The Resurgence of Exogenous Psychosis: A Phenomenological Examination of Substance-Induced Psychopathology. The Journal of Nervous and Mental Disease September 1, 2024
and 2 more in the library