Early-onset schizophrenia: studying the links between cognitive and clinical dimensions

ABSTRACT

Background

Early-onset schizophrenia (EOS), a rare and severe chronic psychiatric condition, is defined by an onset of schizophrenia symptoms before the age of 18. Core symptoms also include cognitive impairments. However, little is known about links between psychiatric symptoms of EOS and cognitive abilities.

Objective

To explore the clinical and neurocognitive profiles of EOS patients and their links.

Method

EOS patients have been phenotyped using standardised psychiatric assessments for DSM-5 diagnoses (K-SADS-PL) and for symptoms (PANSS and SANS), together with neurocognitive evaluations.

Results

The EOS sample (n = 27, 12.4 +/−3.2 years) presented hallucinations (83%), negative symptoms (70%) and delusion (59%). 81% of patients presented comorbidities such as anxiety disorders (33%), autism spectrum disorder (26%) and attention-deficit hyperactivity disorder (26%). Patients presented borderline intellectual deficiency (total IQ = 72.5 +/−4.7), with low performances in working memory subtest. We highlight a positive correlation between the IQ and intensity of positive symptoms (PANSS) and between the IQ and a first treatment being administered at an older age. We also highlight a negative correlation between the IQ and attention items of SANS.

Conclusion

Cognitive skills are correlated with symptom intensity in EOS patients. An older age of onset seems to be a protective factor for cognitive development.

KEYWORDS:

• Early-Onset Schizophrenia
• neurocognitive deficit
• clinical symptoms
• comorbidities
• cognitive remediation

Acknowledgments

We acknowledge the “Direction de la Recherche Clinique” of the Nice University Hospital. As well the Marseille University Hospital Centre, Professor François Poinso and Doctor Xavier Salle-Collemiche and all the medico-social and sanitary centres, partners of the study. The authors are grateful to Anne-Lise Tosello, Fanny Maria and Andreia Santos for specify help and to Maria Capovilla and Xavier Mondoloni for revising the manuscript.

Ethics approval

The study was approved by the ethical committee “Sud Méditerranée V” (ref.2011-A00787-34) and the French National Agency for Medicines and Health Products Safety (ANSM, n°B111395-70).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Additional information

Funding

The research is funded by the French Health Ministry. It is a Programme Hospitalier de Recherche Clinique, PHRC-I 2011.