So the different types of insomnia in childhood include insomnia due to inadequate sleep hygiene. You know children have computers, TVs, phones in their bedroom, and all those devices do delay sleep onset. What they don't realize is that these activities can hamper their sleep for two different reasons. One is if you're using the computer or you're watching TV you become engaged in what you're doing, and that will cause you to become stimulated which makes it harder to fall asleep and stay asleep.
Another reason is that light from TVs and computers can also hamper your melatonin secretion. Melatonin is a hormone that is secreted by our pineal gland which helps with sleep onset. Now, light is the most activating factor for us. We have receptors that are located in our retina which will take that light and send that signal to our brain that it's time to stay awake. So increasing light exposure in the evening hours will suppress our melatonin secretion. So what I tell patients is to avoid electronics starting an hour before your bedtime and stay in dim light to help with the sleep onset process.
You could also have behavioral insomnia of childhood which includes sleep onset association insomnia. This is when kids tend to develop an association with a certain object or their parents and require them to be present to be able to fall asleep. You can also have limit setting insomnia where parents fail to enforce bedtime routines and strict sleep schedules and their children do not fall asleep at the same time every day and wake up at the same time every day.
You can also have certain circadian rhythm disorders that are causing insomnia, especially in the teenage population. This is where delayed sleep phase syndrome comes into play. Your body's own circadian rhythm is offset where you have a tendency to want to sleep later and wake up later. Unfortunately, we can't wake up later because we have school in the daytime.
You can also have other primary sleep disorders such as sleep apnea or restless leg syndrome which will fragment prevent sleep at night and also delay sleep onset.
So further evaluation by your physician is definitely needed to determine whether there's a medical cause or behavioral cause for insomnia in your child.