Adolescence is generally looked upon as a time of emotional upheaval ("adolescent turmoil") during which depression frequently occurs, but in fact the vast majority of teenagers are happy and depression as an illness is rather rare in this age group. This remains so despite the major changes experienced during adolescence in terms of physical and sexual maturity, young people finding their identity as individuals within their family.

However, quite concerning is the rising rate of suicidal behaviour, particularly among boys in this group and among the slightly older group of young adults, which contrasts with the generally declining rates in all other age groups.

We must also underline that depression beginning at such an age is likely to be severe and recurrent and it is therefore important that it is detected and treated effectively. Symptoms are in quality not different from those of adult depression, although irritability and social withdrawal may be prominent, and discordant family relationships also noticeable.