Completed suicide occurs most commonly in older adolescents, and, although it can also occur in children as young as 6 years of age, it is excessively rare before puberty.⁽⁷⁾ Psychological-autopsy studies have shown that about 90 per cent of adolescent suicides occur in individuals with a pre-existing psychiatric disorder, often present for several years.^(3,4,5) In teenagers, the most common disorders are some form of mood disorder, substance and/or alcohol abuse, often comorbid with a mood disorder in boys over age 15, and anxiety disorders.^{(3, 4)} At a trait level, many suicide completers have been noted to be irritable, impulsive, volatile, and prone to outbursts of aggression. However, this pattern of behaviour is by no means universal, and anxious suicides have usually shown no evidence of prior behavioural, academic, or social disturbances.⁽³⁾

Although some adolescents—predominantly girls suffering from a major depressive disorder—appear to have thought about suicide for some time before death, most adolescent suicides appear to impulsively follow a recent stress event, such as getting into trouble at school or with a law-enforcement agency; a ruptured relationship with a boy- or girlfriend; or a fight among friends. In many instances, these stress events can be seen as a by-product of their underlying psychiatric disorder.⁽¹²⁾

It also appears that a completed suicide can be precipitated—in a presumably already suicidal youth-by exposure to news of another person’s suicide, or by reading about or viewing a suicide portrayed in a romantic light in a book, magazine, or newspaper.⁽¹³⁾

About a third of completed suicides have made a previous known suicide attempt, more commonly girls and those who suffered from a mood disorder.⁽³⁾ Completed suicide must be distinguished from autoerotic asphyxia, which is rare in teenagers.⁽³⁾ Suicide pacts, common between middle-aged or elderly married couples and/or other family members, are similarly rare in adolescents, but are not unknown.⁽³⁾

Assessment of a suicide attempt involves an evaluation of the short-term risk for suicide and attempt repetition, and an assessment of the underlying diagnosis or other promoting factors. If the child or teenager has been referred to as an ideator, it is important to determine whether they are contemplating or have secretly attempted suicide.

Repeated attempts, attempts by unusual methods (other than ingestions or superficial cutting), medically serious attempts, and attempts where the patient has taken active steps to prevent discovery all increase the risk for further attempts or death.^(18,19) Children and adolescents systematically overestimate the lethality of different suicidal methods, so that a child with a significant degree of suicidal intent may fail to carry out a lethal act.^(20,21,22)

The mental states leading to suicidal behaviour include anticipatory anxiety, pessimism, or hopelessness, as well as paranoid or other cognitive distortions arising from an underlying psychiatric diagnosis.⁽²³⁾ Inappropriate coping styles (e.g. impulsivity or catastrophizing) in response to external stress may also contribute to the behaviour. Motivating feelings may include the wish to effect a change in interpersonal relationships, to rejoin a dead
relative, to avoid an intolerable situation, to get revenge, or to gain attention.⁽²²⁾

Psychiatric diagnoses commonly associated with a suicide include depression, bipolar disorder, substance abuse, conduct disorder, and overanxious and panic disorders.^(3,4,5) Although the rate of suicide in schizophrenics is high, because of the rarity of the condition, it accounts for very few suicides.

Recurring suicidal behaviour has been associated with hypomanic personality traits and cluster B personality disorders.⁽²²⁾ A history of impulsivity, mood lability, with rapid shifts from brief periods of depression, anxiety, and rage to euthymia and/or mania—associated with transient psychotic symptoms, including paranoid ideas and auditory or visual hallucinations-is associated with a risk for further suicide attempts and is compatible with the diagnosis of borderline personality disorder. Many of these symptoms are also features of bipolar mood disorder.

There is a strong inverse relationship between attempted suicide and age. A large epidemiological survey of four suicide-related behaviours (ideation, plan, gesture, and attempt) in the United States has shown a significantly higher rate of all four behaviours in the youngest age group (15-24 years).⁽²⁹⁾ This study also compared rates of these four behaviours across two decades (1990-1992 and 2001-2003). It found that rates did not decrease, despite a dramatic increase in pharmacologic treatment.

Suicide attempts in adolescents are at least twice as common in females as males (see Figs 9.2.10.1 and 9.2.10.2). Considerable ethnic variation is seen in the United States, with, for unknown
reasons, Hispanic high-school students having twice the rate of black or white teenagers.⁽³⁰⁾