Letter to the Editors

Psychotic-like experiences as overdetermined phenomena: When do they increase risk for psychotic disorder?

The field of psychosis risk research has been remarkably productive and useful, as illustrated in the preceding chapters. There are a number of significant paradigm shifts underway in the field of early psychosis research, involving a combination of theoretical models of mental disorder, how best to index level of risk, and new statistical approaches. These new developments have developed partly from lessons learnt within the field itself and partly from cross-disciplinary dialogue. The particular areas we focus on here include the concepts of pluripotency, the clinical staging model, dynamic modeling, and network theory within the context of the formative “at-risk mental state” concept.

The Ultra-High Risk (UHR) for psychosis group is known to be heterogeneous with diverse outcomes. This study aimed to: 1. Identify subclasses of UHR individuals based on trajectories of symptomatic and functional change over time, 2. Identify predictors of these trajectories.

A sample of 304 UHR individuals participating in the Neurapro trial were followed over an average of 40 months. All participants received cognitive-behavioural case management (CBCM). Symptomatic and functional profiles were investigated using latent class growth analysis. Multinomial regression was employed to investigate predictors of classes.

Identified trajectories showed mostly parallel slopes (i.e. improving symptoms/functioning over time), which were primarily distinct regarding the severity of symptomatology/level of functioning at baseline (i.e. the intercept). Higher symptomatic/lower functioning classes were predicted by higher substance use, older age, female gender, and lower cognitive functioning.

No divergent trajectories were identified as all classes improved over time. This may reflect effective treatment through CBCM, natural illness course, or effective engagement with mental health services. Nonetheless, classes highest in symptoms/lowest in functioning still showed considerable impairment during follow-up, highlighting the need for targeted intervention in these subgroups. The study emphasizes the need for more clinical attention directed towards UHR patients being female or using substances.

This study addresses the psychometric properties of a Spanish validation of the REF scale of ideas of reference (IRs) in detecting and following at-risk mental states and psychosis.

A total of 9447 participants were distributed in three groups: 676 patients with various diagnoses—154 with psychotic disorders, 6291 youths aged 11 to 20, and 2480 adult participants aged 21 to 84.

Youths had higher scores than adults on IRs, observing a progressive decrease and stabilization in the twenties. Exploratory factor analysis provided a structure for the overall IRs score, with five first-order dimensions and one second-order dimension. Confirmatory factor analysis supported the structure with excellent fit. The REF scale was invariant across sex and samples. The internal consistency of the complete scale was excellent and acceptable across the five first-order factors. Strong relationships were found with the positive dimension of the community assessment of psychic experience-42, as well as with aberrant salience. Low and moderate relationships were found with public self-consciousness, anxiety, and depression. Youths and patients diagnosed with schizophrenia and other psychotic disorders had a high mean IRs frequency. Male sex, greater age (among the adults), and the “causal explanations”, “Songs, newspapers, books” and “laughing and commenting” REF subscales showed predictive power in the diagnostic categories of schizophrenia and other psychotic disorders.

The results provide satisfactory that the REF scale could be used to study psychosis.

Schizotypal personality disorder (SPD) symptoms or features are common in patients with psychosis and their healthy relatives. However, the long-term stability of these SPD features and therefore their constituting enduring traits underlying vulnerability to psychosis remain to be clarified. Thirty-two patients with psychotic disorders and 29 of their healthy siblings were included from the long-term follow-up study of 89 nuclear families. Participants were clinically assessed by means of a semi-structured diagnostic interview, whereas the Schizotypal Personality Questionnaire-Brief (SPQ-B) was applied for the self-assessment of SPD symptoms. The assessments were carried out upon admission to the study and at follow-up, about 10 years later. The patients had higher scores than their siblings on the SPQ-B both at baseline and follow-up. In addition, self-reported SPD symptoms remained stable over time in total scores and in all the SPQ-B subscores, except for the SPQ-B Disorganization subscale. Self-reported SPD symptoms were stable over the long term among patients with psychotic disorders and their healthy siblings. This finding provides new support for including the SPD construct as a trait measure for studies addressing both vulnerability to psychosis in first-degree relatives of patients with psychosis and long-term persistence of symptoms in patients suffering from psychosis.

Persisting psychotic-like experiences (PLEs) are associated with an increased risk of internalising symptoms in adolescence. Whether this association holds similarly for externalising symptoms, and from mid-childhood, is unclear. This prospective study investigated the extent to which PLE persistence was associated with internalising and externalising psychopathology in a community sample of children aged 9–11 years at study commencement.

8099 children (mean age 10.4 years) completed questionnaires assessing PLEs, externalising and internalising symptoms. A subsample of 547 children completed reassessment, on average, two years later.

Two-thirds (66%) of children reported PLEs at baseline. Approximately two years later, PLEs persisted in 39% of those children. After adjustment for previous psychopathology and other potential confounds, children with persisting PLEs were at higher risk for internalising (odds ratio [OR] = 1.94; 95% confidence interval [CI] 1.13–3.34) and externalising (OR = 1.97; 95% CI 1.19–3.26) psychopathology than children whose PLEs remitted; and, than children who never presented PLEs.

Persistent PLEs from mid-childhood are associated with later internalising and externalising psychopathology in the general population, whereas transitory PLEs may be part of a spectrum of normative childhood development. Interventions that target persistent PLEs may contribute to a reduction in common childhood psychopathology.

The main goal of the present study was to examine the relationship between the schizotypy dimensions, emotional–behavioural problems and personality disorder traits in non-clinical general adolescent population. A total of 1455 participants (M = 15.9 years; S.D. = 1.2) were administered the Oviedo Schizotypy Assessment Questionnaire (ESQUIZO-Q), the Strengths and Difficulties Questionnaire (SDQ) and the Personality Diagnostic Questionnaire-4+ (PDQ-4+). Correlation analyses revealed significant associations between the schizotypy and emotional–behavioural problems self-reported by adolescents. Participants with high scores in schizotypy dimensions, reported higher rates of affective and behavioural problems than those with low scores. Also, schizotypy dimensions and personality disorder traits were closely related in adolescent population. These data indicate, as occurs in clinical samples, the high overlap between schizotypy and personality disorder traits. Affective dysregulation and behavioural problems are present at the subclinical level in non-clinical adolescent population. These results have implications for the integration of schizotypy studies within the paradigms of developmental psychology and dimensional models of personality.