Children between the ages of 6 and 12 need about 10 to 11 hours of sleep each night, and teens need about 9 hours of sleep each night.
If parents set a realistic bedtime and child is still not getting a good night's sleep, than common causes of insomnia can include:
 Poor sleep habits
 Caffeine
 Stress
 Obstructive sleep apnea (snoring)
 Side effects of medications, including stimulants used to treat adhd, antidepressants, corticosteroids, and anticonvulsants
 Asthma (coughing)
 Eczema (itching)
 Depression
 Anxiety
 Restless legs syndrome
 Neurodevelopmental disorders, such as autism, mental retardation, and asperger's syndrome

Treatment
Unless there is another or co-morbid diagnosis as a cause of child's insomnia, a prescription is usually not the answer.
Non-drug treatments for primary insomnia, or childhood insomnia that is not caused by another medical condition, can include:
 Restricting time spent in bed to simply sleeping, which means no reading, doing homework, or watching TV in bed
 Having a very consistent schedule of when your child goes to bed and wakes up, including weekends and holidays
 Stopping stimulating activities 30 to 60 minutes before bedtime, such as playing video games, watching TV or talking on the phone
 Getting out of bed and doing something quiet, such as reading, if your child doesn't fall asleep within 10 to 20 minutes
 Avoiding caffeine
 Exercising regularly

Homoeopathic Treatment
Cina : This is a children's remedy corresponding to many conditions that may be referred to intestinal irritation, such as worms and accompanying complaints. An irritability of temper, variable appetite, grinding of teeth, and even convulsions, with screams and violent jerkings of the hands and feet, are all within its range of action. The Cina patient is hungry, cross, ugly, and wants to be rocked. Pain in shocks.
Ill-humor. Child very cross; does not want to be touched, or crossed, or carried. Desires many things, but rejects everything offered. Choreic movements of face and hands.Child gets on hands and knees in sleep; on abdomen.
Night terrors of children; cries out, screams, wakes frightened. Troubles while yawning. Screams and talks in sleep. Grits teeth.

Chamomilla : sensitive, irritable, thirsty, hot, and numb. Oversensitiveness from abuse of coffee and narcotics. Night-sweats. Whining restlessness. Child wants many things which he refuses again. Piteous moaning because he cannot have what he wants. Child can only be quieted when carried about and petted constantly. Impatient, intolerant of being spoken to or interrupted; extremely sensitive to every pain; always complaining. Complaints from anger and vexation. Mental calmness contraindicates Chamom.
Drowsiness with moaning, weeping and wailing during sleep; anxious, frightened dreams, with half-open eyes. Worse, by heat, anger, open air, night. Better, from being carried.

Calc carb: -Ideas crowding in mind prevent sleep. Horrid visions when opening eyes. Starts at every noise; fears that will go crazy. Drowsy in early part of evening. Frequent waking at night. Same disagreeable idea always arouses from light slumber. Night terrors. Dreams of the dead.

Lyco: -Drowsy during day. Starting in sleep. Dreams of accidents. afraid to be alone. Little things annoy, Extremely sensitive. Loss of self-confidence. Hurried when eating. Apprehensive. Weak memory, confused thoughts; spells or writes wrong words and syllables. Cannot read what he writes. Sadness in morning on awaking. worse from about 4 to 8 p.m.

Psorinum : Sleepless from intolerable itching. Easily startled.

Tatrentula : Restless feet. -Drowsiness. Sleep restless. Sleep prevented by harsh cough.

Ars alb : Disturbed, anxious, restless. Must have head raised by pillows. Suffocative fits during sleep. Sleeps with hands over head. Dreams are full of care and fear. Drowsy.

Sulphur : Very forgetful. Difficult thinking. Busy all the time. Irritable. Affections vitiated; very selfish, no regard for others. Talks, jerks, and twitches during sleep. Vivid dreams. Wakes up singing. Wakes frequently, and becomes wide awake suddenly. Catnaps; slightest noise awakens. Cannot sleep between 2 an 5 a.m.

Coffea : Gaiety, easy comprehension, irritability, excited; senses acute. Impressionable, especially to pleasurable impressions. Full of ideas, quick to act. Tossing about in anguishWakeful; on a constant move. Sleeps till 3 a.m., after which only dozing. Wakes with a start, sleep disturbed by dreams. Sleepless, on account mental activity; flow of ideas, with nervous excitability.

Silicea : Nervous and excitable. Sensitive to all impressions. Brain-fag. Obstinate, headstrong children. Abstracted. Fixed ideas; thinks only of pins, fears them, searches and counts them. Night-walking; gets up while asleep. Sleeplessness, with great orgasm of blood and heat in head. Frequent starts in sleep. Anxious dreams. Excessive gaping.

Baryta carb: Children dwarfish, do not grow and develop. Loss of memory, mental weakness. Irresolute. Lost confidence in himself. Talking in sleep; awakens frequently; feels too hot. Twitching during sleep.

Kali phos : Prostration. Weak and tired. Anxiety, nervous dread, lethargy. Indisposition to meet people. Extreme lassitude and depression. Very nervous, starts easily, irritable. Brain-fag; hysteria; night terrors. Somnambulance. Loss of memory. Slightest labor seems a heavy task. Great despondency about business. Shyness; disinclined to converse.