Specificity of childhood psychotic symptoms for predicting schizophrenia by 38 years of age: a birth cohort study

Abstract

Background Childhood psychotic symptoms have been used as a subclinical phenotype of schizophrenia in etiological research and as a target for preventative interventions. However, recent studies have cast doubt on the specificity of these symptoms for schizophrenia, suggesting alternative outcomes such as anxiety and depression. Using a prospective longitudinal birth cohort we investigated whether childhood psychotic symptoms predicted a diagnosis of schizophrenia or other psychiatric disorders by 38 years of age. Method Participants were drawn from a birth cohort of 1037 children from Dunedin, New Zealand, who were followed prospectively to 38 years of age (96% retention rate). Structured clinical interviews were administered at age 11 to assess psychotic symptoms and study members underwent psychiatric assessments at ages 18, 21, 26, 32 and 38 to obtain past-year DSM-III-R/IV diagnoses and self-reports of attempted suicides since adolescence. Results Psychotic symptoms at age 11 predicted elevated rates of research diagnoses of schizophrenia and post-traumatic stress disorder (PTSD) and also suicide attempts by age 38, even when controlling for gender, social class and childhood psychopathology. No significant associations were found for persistent anxiety, persistent depression, mania or persistent substance dependence. Very few of the children presenting with age-11 psychotic symptoms were free from disorder by age 38. Conclusions Childhood psychotic symptoms were not specific to a diagnosis of schizophrenia in adulthood and thus future studies of early symptoms should be cautious in extrapolating findings only to this clinical disorder. However, these symptoms may be useful as a marker of adult mental health problems more broadly.

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

“…First, the association between PE and suicidal ideation and behaviour has been investigated mostly in cross-sectional studies (Capra et al, 2015;DeVylder et al, 2015b;Jang et al, 2014;Kelleher et al, 2012c;Nishida et al, 2010;Saha et al, 2011;Temmingh et al, 2011), disabling causal inferences. Second, several studies included psychiatric diagnoses in the regression models to control for confounding (Calkins et al, 2014;DeVylder et al, 2015b;Fisher et al, 2013;Koyanagi et al, 2015;LewisFernandez et al, 2009;Olfson et al, 2002;Saha et al, 2011;Sharifi et al, 2015). However, it is conceptually impossible to examine a confounder in the association between PE and suicidal behaviour when that confounder, for example depression, is fundamentally associated with the outcome (Miller and Chapman, 2001).…”

Stimulant Medication and Psychotic Symptoms in Offspring of Parents With Mental Illness

“…Several longitudinal studies have suggested that childhood psychotic symptoms may predict psychotic disorders in adulthood, 26,35,36 whereas other studies suggest a relatively good prognosis of psychotic symptoms in children. [37][38][39] It should be noted that most stimulantassociated psychotic symptoms were hallucinations and there is lack of consensus about the predictive value of hallucinations in children.…”

“…41,42 On the other hand, PLEs that were overwhelmingly hallucinations predicted psychotic symptoms and disorders in adulthood in several large cohorts. 26,35,36,43 Although more data are needed on the longterm prognosis of hallucinations in childhood, recent reviews lean toward considering hallucinations in childhood as indicators of increased risk of adult psychiatric disorders. 44,45 At present, it is unclear if psychotic symptoms provoked by stimulant medication carry prognostic implications.…”

Hot and cold executive functions in youth with psychotic symptoms

“…General population studies have found that 10-17% of children and 7.5% of adolescents report unusual experiences that are undistinguishable from delusions and hallucinations that occur in SMI (Kelleher et al 2012a, b). Psychotic symptoms in childhood are associated with family history of psychotic and mood disorders (Polanczyk et al 2010;Zammit et al 2013Zammit et al , 2014 and predict a range of psychiatric disorders in adulthood, including schizophrenia, other forms of SMI, as well as suicide attempts (Poulton et al 2000;Welham et al 2009;Fisher et al 2013). Therefore, psychotic symptoms in childhood and adolescence may represent early manifestations of liability, and understanding their underlying mechanisms may provide clues to the etiology and prevention of SMI.…”