Hello doctor, my son is 14 years old. He is going through puberty and there are quite a lot of psychological and physical changes, so I am very worried. Recently, I read an article saying that insomnia can be a sign of mental illness, and teenagers are especially prone to depression during puberty, so I am quite anxious. My son has actually been sleeping very little for about a year now, and his emotions also change quite frequently. I would like to ask whether my son needs to see a psychologist, or if this is just normal developmental changes. Could you please tell me: does prolonged insomnia mean mental illness? Thank you very much.