Individuals who report psychotic-like experiences are at increased risk of future clinical psychotic disorder. They constitute a unique "high-risk" group for studying the developmental trajectory to schizophrenia and related illnesses. Previous research has used screening instruments to identify this high-risk group, but the validity of these instruments has not yet been established. We administered a screening questionnaire with 7 items designed to assess psychotic-like experiences to 334 adolescents aged 11-13 years. Detailed clinical interviews were subsequently carried out with a sample of these adolescents. We calculated sensitivity and specificity and positive predictive value (PPV) and negative predictive value (NPV) for each screening question for the specific symptom it enquired about and also in relation to any psychotic-like experience. The predictive power varied substantially between items, with the question on auditory hallucinations ("Have you ever heard voices or sounds that no one else can hear?") providing the best predictive power. For interview-verified auditory hallucinations specifically, this question had a PPV of 71.4% and an NPV of 90.4%. When assessed for its predictive power for any psychotic-like experience (including, but not limited to, auditory hallucinations), it provided a PPV of 100% and an NPV of 88.4%. Two further questions-relating to visual hallucinations and paranoid thoughts-also demonstrated good predictive power for psychotic-like experiences. Our results suggest that it may be possible to screen the general adolescent population for psychotic-like experiences with a high degree of accuracy using a short self-report questionnaire.
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"Krebs, Paris), ou le Structured Interview for Prodromal Symptoms (SIPS). Un outil simple d'emploi a également démontré son excellente valeur prédictive en population générale : le 7-items Adolescent Psychotic-like Symptom Screener (APSS) (Tableau 1)  . Une étude EMC -Psychatrie/Pédopsychiatrie menée chez 7900 enfants âgés de 9 à 11 ans a effectivement pu montrer que l'item 4 de l'APSS portant sur les expériences hallucinatoires auditives et l'item 6 portant sur les expériences hallucinatoires visuelles possédaient le plus grand pouvoir discriminant dans la détection d'un construct « psychose » dans cette tranche d'âge  . "
[Show abstract][Hide abstract] ABSTRACT: Les psychoses sont sans doute la préoccupation constante des psychiatres d'adolescents qui craignent avant tout l'entrée dans la schizophrénie qu'ils sont conduits à évoquer devant des symptômes très divers venant exprimer de façon polymorphe la souffrance psychique fréquente à cet âge. En effet, l'adolescence, qui est un moment de profondes mutations internes et externes, est aussi l'âge où s'installent la plupart des maladies psychiatriques de l'âge adulte, celles-ci n'ayant pas, à leur début, les caractéristiques cliniques qui les rendront plus tard plus facilement reconnaissables. Devant des symptômes psychotiques à l'adolescence, le clinicien doit donc envisager un large éventail de diagnostics différentiels sans pouvoir se fier aux descriptions nosographiques. Il est donc, plus qu'à d'autres âges de la vie, amené à prendre en compte la dimension psychopathologique des troubles autour de deux grands axes théoriques : l'Œdipe et le corps génital d'une part et la psychopathologie des liens d'autre part. S'interroger sur les psychoses à l'adolescence aujourd'hui c'est aussi tout à la fois tolérer un certain degré d'incertitude pronostique et se poser la question de la valeur des manifestations prémorbides apparaissant à cette période de la vie : facteurs de vulnérabilité ou prodromes de la maladie avec pour conséquence des modalités de traitement et de prévention qui peuvent être très différentes.
"However, briefly, a total of 1131 pupils from 16 schools in the 5th and the 6th class (that is, the two most senior years in the Irish national/primary school system), aged 11 to 13 years, participated in a survey of psychiatric symptoms, using the Strengths and Difficulties Questionnaire (SDQ) (Goodman et al., 2000), which is a validated self-report instrument that assesses emotional symptoms, conduct problems, hyperactivity/inattention, peer relationship problems , and prosocial behaviour. This sample was also assessed for psychotic experiences, using the Adolescent Psychotic Symptom Screener (APSS), which is a validated self-report instrument that assesses hallucinations and delusions (Kelleher et al., 2011). These instruments were completed in school, with a member of the research team present in the classroom. "
"For instance, recent studies of children in Ireland and Greater London found that children's questionnaire endorsement of hallucinations (e.g., " yes, definitely " to the question " Have you ever heard voices or sounds that no one else can hear? " ) was associated most closely with a latent psychosis construct, and had the highest predictive power for psychotic-like symptoms on interview (Kelleher et al., 2011a; Laurens et al., 2012). Yet, the retrospective report of symptoms by FES participants in the current study suggests that their childhood experience of attenuated psychotic symptoms was not dominated by hallucinatory experiences; delusional and persecutory ideas were just as common. "
[Show abstract][Hide abstract] ABSTRACT: Background
Psychosis prevention and early intervention efforts in schizophrenia have focused increasingly on sub-threshold psychotic symptoms in adolescents and young adults. Although many youth report symptom onset prior to adolescence, the childhood incidence of prodromal-level symptoms in those with schizophrenia or related psychoses is largely unknown.
This study reports on the retrospective recall of prodromal-level symptoms from 40 participants in a first-episode of schizophrenia (FES) and 40 participants at “clinical high risk” (CHR) for psychosis. Onset of positive and non-specific symptoms was captured using the Structured Interview for Prodromal Syndromes. Frequencies are reported according to onset during childhood (prior to age 13), adolescence (13–17), or adulthood (18 +).
Childhood-onset of attenuated psychotic symptoms was not rare. At least 11% of FES and 23% of CHR reported specific recall of childhood-onset of unusual or delusional ideas, suspiciousness, or perceptual abnormalities. Most recalled experiencing non-specific symptoms prior to positive symptoms. CHR and FES did not differ significantly in the timing of positive and non-specific symptom onset. Other than being younger at assessment, those with childhood onset did not differ demographically from those with later onset.
Childhood-onset of initial psychotic-like symptoms may be more common than previous research has suggested. Improved characterization of these symptoms and a focus on their predictive value for subsequent schizophrenia and other major psychoses are needed to facilitate screening of children presenting with attenuated psychotic symptoms. Accurate detection of prodromal symptoms in children might facilitate even earlier intervention and the potential to alter pre-illness trajectories.
Schizophrenia Research 09/2014; 158(1-3). DOI:10.1016/j.schres.2014.05.017 · 3.92 Impact Factor