Clinical presentation of Attenuated Psychosis Syndrome in children and adolescents: Is there an age effect?

Highlights

• APS in early compared to late adolescence have been specifically investigated.

• Earlier age of presentation with APS is associated with more severe presentation and worse functioning.

• Functioning severity could be predicted by age of presentation.

Abstract

There is limited research on clinical features related to age of presentation of the Attenuated Psychosis Syndrome in children and adolescents (CAD). Based on findings in CAD with psychosis, we hypothesized that an older age at presentation of Attenuated Psychosis Syndrome would be associated with less severe symptoms and better psychosocial functioning than presentation in childhood or younger adolescence. Ninety-four CAD (age 9–18) meeting Attenuated Psychosis Syndrome criteria participated in the study. The sample was divided and compared according to the age of presentation of Attenuated Psychosis Syndrome (9–14 vs 15–18 years). The predictive value of age of Attenuated Psychosis Syndrome presentation was investigated using receiver operating characteristic (ROC)-curve calculations. The two Attenuated Psychosis Syndrome groups were homogeneous in terms of gender distribution, IQ scores and comorbid diagnoses. Older Attenuated Psychosis Syndrome patients showed better functioning and lower depressive scores. ROC curves revealed that severity of functional impairment was best predicted using an age of presentation cut-off of 14.9 years for social functioning and 15.9 years for role functioning. This study partially confirmed our hypothesis; older age at presentation of Attenuated Psychosis Syndrome was associated with less functional impairment, but age was not associated with psychotic symptoms.

Introduction

For the first time, the Diagnostic and Statistical Manual of Mental Disorders version 5 (DSM -5) has introduced the Attenuated Psychosis Syndrome in Section III under “Conditions for further study” (APA, 2013). The diagnostic structure of Attenuated Psychosis Syndrome is based primarily on risk criteria from the Structured Interview for Psychosis Risk Syndromes (SIPS; Miller et al., 1999) and the Comprehensive Assessment of At-Risk Mental States (CAARMS; Yung et al., 2005) which relate to attenuated/subthreshold psychotic symptoms and the prodromal states of schizophrenia. The diagnosis of Attenuated Psychosis Syndrome requires the presence of delusions, hallucinations, or disorganised speech in an attenuated form that are present at least once per week for the past month, not better explained by another diagnosis, and which have never been severe enough for the patient to meet diagnostic criteria for a psychotic disorder (APA, 2013).

Several issues have been raised with the introduction of this new category. For example, it is well recognized that attenuated psychotic symptoms are associated with comorbid non-psychotic disorders in individuals who may never develop psychosis (Cannon et al., 2008; Gaudiano and Zimmerman, 2013; Lin et al., 2015). There are also concerns over the treatment implications of ascribing a diagnosis of Attenuated Psychosis Syndrome (Singh et al., 2012). It also remains unclear whether the threshold for psychosis may be lower and/or transient in younger patients (Arango, 2011). Indeed, some studies of adolescent samples have reported that attenuated positive symptoms may be non-specific and/or transient in this population (Gerstenberg et al., 2016) and that the ultra-high risk (UHR) criteria may fail to predict conversion to psychosis (Welsh and Tiffin, 2014; Lindgren et al., 2014; Armando et al., 2015). The validity of screening instruments for children has also been questioned (Schimmelmann and Schultze-Lutter, 2012), and new instruments have been developed specifically for younger children (e.g., The Schizophrenia Proneness Instrument, Child and Youth Version (SPI-CY); Fux et al. (2013)).

Despite these concerns, others have expressed confidence that the development of the Attenuated Psychosis Syndrome diagnosis will encourage the recognition of individuals at UHR or clinical high risk (CHR) for psychosis, particularly in child and adolescent populations (Schiffman and Carpenter, 2015). It has recently been reported that at least 11% of individuals with a first episode of psychosis and 23% of individuals at heightened risk for psychosis reported unusual or delusional ideas, suspiciousness or perceptual abnormalities during childhood (Woodberry et al., 2014).

A relatively small number of studies have specifically investigated the clinical presentation of Attenuated Psychosis Syndrome in children and adolescents. These studies, all in general population samples, reported variability in attenuated psychotic symptoms at different ages of presentation (Schimmelman et al., 2013), with a tendency to decrease and remit from childhood through to adolescence (Bartels-Velthuis et al., 2011, Kelleher et al., 2012, Brandizzi et al., 2014, Schimmelmann et al., 2015). In particular, two studies examined the prevalence of attenuated psychotic symptoms in community samples of children and adolescents and both found an age effect. Kelleher and colleagues (2012) showed that younger adolescents had a higher prevalence of psychotic symptoms (21–23%) than older adolescents (7%). Similarly, findings from the BEARS-Kid Study indicated the important role played by age in both the prevalence and clinical presentation of Attenuated Psychosis Syndrome (Schimmelmann et al., 2015). In particular, younger participants more frequently exhibited perceptive symptoms than older participants. Together, these results indicate a significant shift in the presentation Attenuated Psychosis Syndrome from early to late adolescence, at approximately 16 years of age, in young people in the community.

Less is known about the relevance of an “age effect” of Attenuated Psychosis Syndrome in clinical populations of children and adolescents. We recently reported the effect of age at presentation in a sample of patients with early (<18 years of age) and very early (≤12 years of age) onset psychosis (Lin et al., 2016). Applying receiver operating characteristic (ROC)-curve calculations we found that an optimal age cut-off was 14 years for positive symptoms and 14.7 years for psychosocial functioning, with older adolescents showing less severe positive symptoms and better functioning than children and younger adolescents.

The aim of the current paper was to investigate whether this finding would be replicated in a children and adolescents of a similar age presenting to clinical services with Attenuated Psychosis Syndrome. Therefore, based on our previous findings (Lin et al., 2016), we adopted the cut-off of 14 years of age (inclusive) to distinguish between participants with an early vs later presentation of the Attenuated Psychosis Syndrome. We then used ROC-curve calculations to determine the optimal age cut-off for severity of symptoms and psychosocial functioning.