Clinicopathological significance of psychotic experiences in non-psychotic young people: evidence from four population-based studies

Abstract

Hallucinations and delusions, the classic symptoms of psychosis, have recently been documented to occur at a much higher prevalence in the general population than clinically diagnosed psychotic disorder.1 A meta-analysis of prevalence studies of psychotic symptoms in young people demonstrated a median prevalence of 17% in children aged 9-12 years and 7.5% in adolescents aged 13-18 years.2 As the term suggests, psychotic symptoms have typically been considered to relate to psychotic disorder. Indeed, research has shown that members of the general population who report psychotic symptoms share a wide range of risk factors with people with schizophrenia (see Kelleher & Cannon for review), [3][4][5][6][7][8][9] and young people who report psychotic symptoms have been found to be at increased risk of psychotic disorder in adulthood.10,11 Individuals who report psychotic symptoms are also more likely to report non-psychotic psychopathological symptoms, especially symptoms of depression; [12][13][14][15][16] Yung et al, for example, reported that individuals who had a diagnosed depressive disorder endorsed an increased number of psychotic symptoms on the Community Assessment of Psychic Experiences questionnaire compared with controls.17 Bartels-Velthuis et al found that young adolescents who disclosed psychotic symptoms were approximately 3-5 times more likely to score in the clinical psychopathology range on the parent-completed Child Behavior Checklist. Community-based studies to date, however, have relied mainly upon questionnaires to assess psychotic symptoms and have involved limited data on non-psychotic psychopathology. In addition, although research suggests that psychotic symptoms are more common in younger than in older children, 2 there is a lack of information on whether there are differences in the clinical significance of psychotic symptoms across different stages of adolescence. In an attempt to improve our understanding of the clinical significance of psychotic symptoms in the general population we examined data from four population studies, comprising two large population surveys and two in-depth clinical interview studies of psychotic symptoms. The aims of this work were to investigate whether psychotic symptoms predicted nonpsychotic clinical diagnoses, and if so, which disorders; to investigate whether psychotic symptoms predicted more clinically severe disorder in terms of comorbid psychopathology (i.e. having more than one diagnosis); and to investigate whether the significance of psychotic symptoms varied as a function of age. MethodSurvey studies Background Epidemiological research has shown that hallucinations and delusions, the classic symptoms of psychosis, are far more prevalent in the population than actual psychotic disorder. These symptoms are especially prevalent in childhood and adolescence. Longitudinal research has demonstrated that psychotic symptoms in adolescence increase the risk of psychotic disorder in adulthood. There has been a lack of research, however, on the immediate clini...

Psychotic experiences and incident suicidal ideation and behaviour: Disentangling the longitudinal associations from connected psychopathology

“…However, more research on underlying mechanisms is 13 required. The results of the present study show that PE serve as an indicator of illness severity and poor outcome in persons with non-psychotic psychopathology, in line with previous research (Guloksuz et al, 2015;Kelleher et al, 2012b;Perlis et al, 2011;Wigman et al, 2012;Wigman et al, 2014). Therefore, assessment of PE in individuals with non-psychotic psychopathology should be incorporated both in clinical practice and in future research, as previously suggested (Kelleher et al, 2013), in order to identify individuals at risk of suicidal behaviour.…”

“…It remains unclear, however, how to isolate this specific association from the association between non-psychotic psychopathology and suicidal ideation and behaviour, since non-psychotic psychopathology is strongly connected to both PE (DeVylder et al, 2014;Guloksuz et al, 2015;Jeppesen et al, 2015;Kelleher et al, 2012b;Van Os et al, 2000), and suicidal behaviour (Cavanagh et al, 2003;ten Have et al, 2009;Ten Have et al, 2013). Suicidality comprises various phenomena on a continuum ranging from suicidal ideation, suicide plans and suicide attempts to completed suicide (Nock, 2010;Sveticic and De Leo, 2012).…”

“…PE were identified as a risk factor for several mental health outcomes including both psychotic (Kaymaz et al, 2012;Linscott and van Os, 2013) and non-psychotic psychopathology (Kelleher et al, 2012b) and are associated with increased treatment use and need for care in general population samples (Murphy et al, 2012). Moreover, PE serve as an indicator of illness severity and poor outcome in persons with non-psychotic psychopathology (Guloksuz et al, 2015;Kelleher et al, 2012b;Perlis et al, 2011;Wigman et al, 2012;Wigman et al, 2014) A recent meta-analysis reported that general population individuals with PE had an increased risk of both suicidal thoughts (i.e. suicidal ideation or suicidal plans) and suicidal behaviour (i.e.…”

“…At least half of all individuals with PE have a diagnosable mental disorder (DeVylder et al, 2014;Jeppesen et al, 2015;Kelleher et al, 2012b;Van Os et al, 2000). Moreover, individuals with PE without a mental disorder are at increased risk to develop one (Kaymaz et al, 2012;Kelleher et al, 2012b;Linscott and van Os, 2013).…”

“…Moreover, individuals with PE without a mental disorder are at increased risk to develop one (Kaymaz et al, 2012;Kelleher et al, 2012b;Linscott and van Os, 2013). Therefore, it remains unclear whether there is a specific association between PE and suicidal behaviour or whether the association reflects the increased risk of suicidal behaviour in more severe states of mental distress associated with multidimensional psychopathology (Guloksuz et al, 2015;van Nierop et al, 2015b).…”