CONTENTS -- AUTHORS' APPOINTMENTS -- FOREWORD -- INTRODUCTION -- 1 INTELLECTUAL DISABILITIES AND THEIR COMORBIDITIES -- Terminology -- Features associated with intellectual disability -- Reasons for psychiatric and psychological comorbidities -- Down syndrome: an illustration of a specifi c aetiological cause of intellectual -- Frequent clinical common fi nal pathways -- Self-injury -- The need for a conceptual shift -- Example of multidimensional aetiologically driven developmental and -- Conspicuousness by absence -- Conclusion -- REFERENCES -- 2 HETEROGENEITY IN CEREBRAL -- Introduction -- Terminology -- Brain syndromes -- Neurological heterogeneity and cerebral palsy -- Pervasive developmental disorders and cerebral palsy -- Conclusions -- REFERENCES -- 3 GILLES DE LA TOURETTE SYNDROME -- Symptoms and diagnosis of Gilles de la Tourette syndrome -- The comorbidities of Gilles de la Tourette syndrome -- Relationship between Gilles de la Tourette syndrome and its comorbidities -- Management -- REFERENCES -- 4 COMORBIDITY IN NEURODEVELOPMENTAL DISORDERS: -- Impact of classifi cation schemes on comorbidity -- Associations with other neurodevelopmental problems -- Common disorders of mental health -- Associations with brain disorders -- General conclusions -- REFERENCES -- 5 EARLY LANGUAGE DISORDER AS A FREQUENT COMORBIDITY IN MANY DEVELOPMENTAL DISORDERS IN YOUNG CHILDREN -- Preliminary comment regarding comorbidity -- Some conditions associated with inadequate language development -- Conclusion -- REFERENCES -- 6 AUTISM AND EPILEPSY: COMORBIDITY, COEXISTENCE OR COINCIDENCE? -- Prevalence of epilepsy in autism and of autism in epilepsy -- Gender aspects -- Diagnostic/differential diagnostic aspects including electroencephalogram -- Types of seizures -- Electrophysiology -- Conclusion -- REFERENCES.

7 GENETIC CORRELATES OF PSYCHIATRIC COMORBIDITY: -- Molecular biology of fragile X syndrome -- Comorbidities of fragile X syndrome -- Intellectual disability -- Psychosis and fragile X syndrome -- Anxiety and fragile X syndrome -- Autism and fragile X syndrome -- The premutation and fragile X-associated tremor/ataxia syndrome -- Conclusion -- REFERENCES -- 8 CHANNELOPATHIES -- The primary episodic ataxias -- Dravet syndrome and other SCN1A-related infantile epileptic encephalopathies -- REFERENCES -- 9 INCREASED LONGEVITY AND THE COMORBIDITIES ASSOCIATED -- Comorbidities associated with intellectual and developmental disabilities -- Down syndrome -- Projected health trends -- REFERENCES -- 10 COMORBIDITY: CLASSIFICATION ARTEFACT AND CLINICAL REALITY -- Comorbidity as a question of definition -- On classification and diagnosis -- Comorbidity as clinical reality -- Future directions -- REFERENCES -- INDEX.