Dr Ping-I Daniel Lin ( left ) Senior lecturer , school of psychiatry , UNSW Sydney ; South Western Sydney Local Health District , Sydney , NSW .

Dr Michael Dudley ( right ) Senior lecturer , school of psychiatry , UNSW Sydney ; South Eastern Sydney Local Health District , Sydney , NSW .

Dr Nabilah Islam ( left ) Registrar in psychiatry , South Western Sydney Local Health District , Sydney , NSW .

Professor Valsamma Eapen ( right ) Chair of infant , child and adolescent psychiatry , UNSW Sydney ; South Western Sydney Local Health District , Sydney , NSW .

First published online on 2 September 2022

INTRODUCTION

SUICIDE is a tragedy that affects not

only the individual victim but also families , friends , communities and society as a whole ; it is the leading cause of death among individuals aged 15-24 years in Australia . 1 The total economic cost of youth suicide in Australia is estimated at $ 22 billion a year . 2 Despite significant efforts and government investment , the suicide rate remains unchanged and is even increasing in some groups of individuals , such as the Indigenous populations . 3 To lower the suicide rate , we need to improve both prevention and intervention strategies .

GPs play a key role as firstline responders to suicidal crisis . Although a proper and timely triage protocol is a priority , GPs also provide aftercare following the acute or intensive interventions . There is a need , therefore , to raise awareness about the often-intertwined youth suicide prevention and intervention strategies to de-escalate the recurrent / ongoing suicide risk . A good understanding of various care pathways , including hospital , community and school-based mental health services , is also critical . In addition , knowledge of the unique neuropsychological features in young people

may hold the key to insightful clinical information questioning and individualised treatment planning .

This How to Treat offers an overview of factors associated with suicide in children / adolescents and aims to provide evidence-based suggestions for the management of suicide in young people .

AETIOLOGY

CAUSES of suicide are complex and involve biological , psychological and social ( environmental ) factors . Aetiology is often heterogeneous and triggered by combinations of biopsychosocial risk factors or cascading events in a person ’ s life . Protective factors include early healthcare support , connectedness with family and community , self-worth and self-esteem and personal , religious or cultural beliefs against suicide . These factors also interact in unique ways ( for example , different sequences ) that may vary with demographics , making risk assessment challenging .

Biological factors

Biological factors associated with

suicide have been studied using neuroimaging , genetics and immunological studies , among others . A growing body of literature on neuroimaging has implicated brain regions

that subserve emotion and impulse regulation such as the ventral prefrontal cortex and dorsal prefrontal cortex , among several other brain regions ( see figures 1 and 2 ). 4 These regions and their connections play a role in the excessive negative as well as blunted positive internal states that can stimulate suicidal ideation , with the dysregulated co-ordination between ventral prefrontal cortex and dorsal prefrontal cortex considered to weaken top-down inhibition of maladaptive behaviours and inflexible decision-making and planning — resulting in progression of suicidal ideation to lethal behaviours . 4 Differences in dorsal prefrontal cortex responses have also been linked to processing of negative emotional stimuli , highlighting the importance of dysregulated processing of negative emotions and in particular specific emotions ( for example , passive viewing of angry faces , but not happy faces ) as well as impulse disinhibition in youth suicidal ideation or attempts . 5 , 6

While genome-wide association studies are inconclusive , several variants in the serotonin transporter gene ( 5-HTT or solute carrier family 6 member 4 [ SLC6A4 ]), the tryptophan hydroxylase 1 gene ( TPH1 ), the gene encoding brain-derived

neurotrophic factor ( BDNF ) and its receptor neurotrophic receptor tyrosine kinase 2 ( NTRK2 ), have all been implicated , although with contradictory findings . 7 , 8 The SLC6A4 and TPH1 genes encode key proteins in the metabolism of serotonin , a neurotransmitter closely related to depressive disorders — the most commonly associated mental illness .

Epigenetic phenomena , such as DNA methylation levels , may reflect environmental exposure , such as childhood maltreatment / trauma , with a recent meta-analysis suggesting methylation changes are independent of comorbid psychiatric disorders . 9 , 10 Further , genes related to other psychiatric conditions , such as BDNF and GABAAα1 genes , may moderate the suicide risk via changes in methylation patterns . 11-13

Psychological factors

Mental health issues , and in particular

substance use , may predispose to suicidality through disinhibition , impulsiveness and impaired judgement . 14 However , no substantial reduction in suicide despite the decrease in alcohol drinking in the young age group implies that the role of alcohol consumption is smaller in adolescents compared with adults . 15 , 16 However , 57 % of