[Childhood insomnia].
AIMS: This work reviews the causes of insomnia in children and attempts to show the difficulties involved in performing a diagnosis to differentiate it from other sleep disorders. METHOD: Insomnia is a disorder in which the sufferer has difficulty in falling or staying asleep. There are multifactorial causes involved in the aetiology of childhood insomnia. In order to understand and diagnose insomnia in childhood it is necessary to have a good knowledge of the mechanisms involved in the genesis of sleeping and waking. We must also take the possible existence of other types of disorders into consideration. Insomnia appears as an imbalance between the systems that maintain the waking state and those that are in charge of activating sleep generating systems. In children, this imbalance depends on the state of functional immaturity peculiar to each age. Rather than a shortage of sleep, childhood insomnia takes the form of a lack of matching between the child s own rhythm or need to sleep and his or her family or social environment. Insomnia is most frequently caused by environmental, behavioural and psychological factors. A correct diagnosis of childhood insomnia has to be based on determining a procedure to differentiate it from parasomnias or motor disorders affecting waking and sleep. CONCLUSIONS: Identifying the causes of childhood insomnia, differentiating it from real insomnia and other sleep disorders, and resolving it are no simple matter because of the influence exerted by the environment and the child s behaviour on how he or she sleeps.