Sleep, seen in its various aspects, suffers modifications over the individual's life and these are more significant in the first years of life. A baby, right after birth, sleeps approximately 16 to 20 hours a day, whereas a two-year-old child sleeps approximately 12 hours. In pre-adolescence, the waking period is at a maximum, and the need for a daily nap is very rare. The lack of daily sleepiness may disguise primary sleep dysfunctions such as sleep apnea and narcolepsy. During puberty, there is an increase in daily sleepiness, as assessed through the multiple sleep latency test, possibly accompanied by an increased need for sleep. Whether there is alteration of the biological (circadian) clock has been questioned, although some authors suggest that there is a trend toward a delay in its phase.

The most frequent psychiatric disorders that may affect sleep in children and adolescents are depression, anxiety, and attention deficit hyperactivity disorder (ADHD). The anxiety profiles present sleep complaints and polysomnographic findings similar to those of adults. However, the occurrence of multiple awakenings during the night is relevant, when the patient reports a sensation of fear and imminent danger.^.

1. Childhood depression

The symptoms of childhood depression are similar to those observed in the adult population, although with some peculiarities such as exaggerated fears and refusal to go to school. It has been shown that, among children presenting altered sleep patterns, 75% complain of insomnia, and 25% report excessive sleepiness. Those with insomnia mainly complain of difficulty in initiating sleep and have the impression that their sleep is superficial and of poor quality, consequently xperiencing difficulty in waking up early to go to school, together with daytime tiredness.^.

1) Polysomnographic findings

Findings have been inconsistent and hardly specific: in childhood (Tanner stages 1 and 2), there is increased sleep latency and decreased latency for the first episode of REM sleep. In adolescents (Tanner stages 3, 4 and 5), in addition to these findings, there is increased REM density.^.

2. Attention deficit hyperactivity disorder

Children with ADHD complain of difficulty in waking up in the morning (perhaps due to sleeping too little), fragmented sleep, poor quality sleep and increased movement during sleep. It has been observed that children with obstructive sleep apnea syndrome, with periodic limb movements or narcolepsy, present more ADHD-related symptoms.^.

1) Polysomnographic findings

In ADHD, increased physical activity during sleep, increased frequency of periodic limb movements and reduction in REM sleep have been observed.

The treatment of ADHD, combined with careful orientation regarding appropriate sleep rhythm, has proven effective. Patients, when untreated, can present increased daytime sleepiness (observed in the multiple sleep latency test). Nevertheless, re-assessment of the treatment with stimulants - better scheduling, reduction of total dosage, etc - when carried out, propitiates better quality sleep and a consequent improvement in daytime behavior.

By: John Garcia, MD;

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