Background During a psychotic episode, patients frequently suffer from severe maladaptive beliefs known as delusions. Despite the abundant literature investigating the simple presence or absence of these beliefs, there exists little detailed knowledge regarding their actual content and severity at the onset of illness. Aims This study reports on delusions during the initiation of indicated treatment for first-episode psychosis (FEP). Method Data were systematically collected from a sample of 636 patients entering a catchment-based early intervention service for FEP. The average severity and frequency of each delusional theme at baseline was reported with the Scale for the Assessment of Positive Symptoms. Delusional severity (globally and per theme) was examined across a number of sociodemographic and clinical variables. Results Delusions were present in the vast majority of individuals experiencing onset of FEP (94%), with persecutory (77.7%) being the most common theme. Persecutory delusions remained consistent in severity across diagnoses, but were more severe with older age at onset of FEP. No meaningful differences in delusional severity were observed across gender, affective versus non-affective psychosis, or presence/absence of substance use disorder. Globally, delusion severity was associated with anxiety, but not depression. Delusions commonly referred to as passivity experiences were related to hallucinatory experiences. Conclusions This community sample offers a rare clinical lens into the severity and content of delusions in FEP. Although delusional severity was consistent across certain sociodemographic and clinical variables, this was not always the case. Future research should now consider the course of delusion themes over time.

Background During a psychotic episode, patients frequently suffer from severe maladaptive beliefs known as delusions. Despite the abundant literature investigating the simple presence or absence of these beliefs, there exists little detailed knowledge regarding their actual content and severity at the onset of illness. Investigating delusions in early clinical samples is critical, because their relatively young, treatment-naïve presentations are less likely to be confounded by the effects of long-term illness or previous interventions. Furthermore, a more detailed view of the association between clinical factors and delusion severity, both globally and per theme, in a larger and more representative sample may improve psychological models and ultimately treatment options. This study reports on delusions during the initiation of indicated treatment for a first episode psychosis (FEP). Methods Data were systematically collected from a sample of 637 service users entering an early intervention service for FEP. The FEP service provides a comprehensive standardized assessment battery with longitudinal follow-up for two years of treatment. The average severity and frequency of each delusional theme at baseline was reported using the Scale for Assessment of Positive Symptoms. Delusional severity, both globally and per theme, was examined across a number of sociodemographic and clinical variables. Results Delusions of a moderate severity or higher were present in the vast majority of individuals experiencing onset of a FEP (94.0%), with persecutory (77.7%), reference (65.5%), and grandiose (40.2%) being the most common themes. Eighty-one percent of service users presented with two or more delusion themes. Persecutory delusions remained consistent in severity across diagnoses, but were more severe with older age of onset (r = .144). No meaningful differences in delusional severity were observed across sex, affective versus non-affective psychosis, or presence/absence of substance abuse or dependence. Global delusion severity was associated with anxiety (r = .205) but not with depression (r = .052), with specific relationships emerging per theme. Delusions commonly referred to as passivity experiences and/or thought alienation, mind reading delusions (r = .242) and delusions of control (r = .247), were related to hallucinatory experiences. We will also examine delusions longitudinally by investigating their relationship to the duration of untreated psychosis and outcomes, along with the stability of delusional content across episodes. Discussion Unlike the more selected samples, confounded treatment effects, and/or varying levels of chronicity seen in previous reports, this community representative sample offers a rare clinical lens into the severity and content of delusions in FEP. While delusional severity remained consistent across certain sociodemographic and clinical variables, this was not always the case. Future work may wish to investigate the evolution of delusions over time, including focusing on specific themes and/or their overlaps, including with smaller samples and in-depth, phenomenologically oriented interviews.

Background There exist few direct studies of delusional content in psychosis across geo-cultural contexts, especially those in which treatment protocols and measures are comparable. To directly examine an illness outcome that is potentially culturally mediated, this study investigated the baseline presentation and longitudinal trajectory of delusions in first-episode psychosis (FEP) across 2 similar treatment settings in Montréal (Canada) and Chennai (India). Study Design Patients entering an early intervention program for FEP in Chennai (N = 168) and Montréal (N = 165) were compared on site-level differences in the presentation of delusions across specific time points over 2 years of treatment. Delusions were measured using the Scale for Assessment of Positive Symptoms. Chi-square and regression analyses were conducted. Study Results At baseline, delusions were more frequent in Montréal than in Chennai (93% vs 80%, respectively; X2(1) = 12.36, P < .001). Thematically, delusions of grandiosity, religiosity, and mind reading were more common in Montréal than in Chennai (all P < .001); however, these baseline differences did not persist over time. Regression revealed a significant time-by-site interaction in the longitudinal course of delusions, which differs from the trajectory of other FEP-positive symptom domains. Conclusions To the best of our knowledge, this is the first direct comparison of delusions in similar programs for FEP across 2 different geo-cultural contexts. Our findings support the notion that delusion themes follow consistent ordinal patterns across continents. Future work is needed to unpack the differences in severity that present at baseline and minor differences in content.

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