Suicide and suicidal behaviour

Abstract

Suicide is a complex public health problem of global importance. Suicidal behaviour differs between sexes, age groups, geographic regions, and sociopolitical settings, and variably associates with different risk factors, suggesting aetiological heterogeneity. Although there is no effective algorithm to predict suicide in clinical practice, improved recognition and understanding of clinical, psychological, sociological, and biological factors might help the detection of high-risk individuals and assist in treatment selection. Psychotherapeutic, pharmacological, or neuromodulatory treatments of mental disorders can often prevent suicidal behaviour; additionally, regular follow-up of people who attempt suicide by mental health services is key to prevent future suicidal behaviour.

Figure 1. Cross-national prevalence of SB

Non-fatal SB data are from the cited references. Suicide fatalities (solid bars) reported are from the World Health Organization’s 2014 report, Mental health: suicide prevention.

Figure 2. Model for suicide risk

Suicide risk is modulated by a range of factors both at the population and individual levels. Population factors related to social cohesion include wide-scale changes to the social structure, societal pressures such as economic turmoil, and social isolation of individuals or groups of individuals. Environmental factors in the population that could impact an individual’s risk for suicide include representation of suicide in the media, accessibility of lethal means of suicide and difficulties in accessing appropriate healthcare. Individual risk factors can be grouped into distal (or predisposing), developmental (or mediating), and proximal (or precipitating) factors, and many of these factors interact to contribute to the risk of developing SBs.

Figure 3. Biological changes in the suicidal brain

5HT, 5-hydroxytryptamine, or serotonin; AMPA, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid; BDNF, Brain-derived neurotrophic factor; Cx, connexin; GABA, γ-aminobutyric acid; GLUL, Glutamine synthetase; IL, interleukin; NMDA, N-Methyl-D-aspartic acid; SERT, serotonin transporter; SLC, solute carrier family; TNF, tumour necrosis factor; TRKB, Tropomyosin receptor kinase B