Nat Rev Neurosci. 2008 December; 9(12): 947–957.
Recent data from the National Comorbidity Survey Replication study55, 57, a nationally representative epidemiological survey of mental disorders, suggest that about half of the population fulfill criteria for one or other psychiatric disorders in their lifetimes. The majority of those with a mental disorder have had the beginnings of the illness in childhood or adolescence. Some anxiety disorders such as phobias and separation anxiety and impulse-control disorders begin in childhood, while other anxiety disorders such as panic, generalized anxiety and post-traumatic stress disorder, substance disorders and mood disorders begin later, with onsets rarely before early teens. Schizophrenia typically begins in late adolescence or the early twenties, with men having a somewhat earlier age of onset compared to women56. Psychiatric disorders with childhood or adolescent onsets tend to be more severe, are frequently undetected early in the illness, and accrue additional co-morbid disorders especially if untreated. It is therefore critical to focus efforts on early identification and intervention.