Suicidal thoughts and behaviors (STBs) are major public health problems that have not declined appreciably in several decades. One of the first steps to improving the prevention and treatment of STBs is to establish risk factors (i.e., longitudinal predictors). To provide a summary of current knowledge about risk factors, we conducted a meta-analysis of studies that have attempted to longitudinally predict a specific STB-related outcome. This included 365 studies (3,428 total risk factor effect sizes) from the past 50 years. The present random-effects meta-analysis produced several unexpected findings: across odds ratio, hazard ratio, and diagnostic accuracy analyses, prediction was only slightly better than chance for all outcomes; no broad category or subcategory accurately predicted far above chance levels; predictive ability has not improved across 50 years of research; studies rarely examined the combined effect of multiple risk factors; risk factors have been homogenous over time, with 5 broad categories accounting for nearly 80% of all risk factor tests; and the average study was nearly 10 years long, but longer studies did not produce better prediction. The homogeneity of existing research means that the present meta-analysis could only speak to STB risk factor associations within very narrow methodological limits-limits that have not allowed for tests that approximate most STB theories. The present meta-analysis accordingly highlights several fundamental changes needed in future studies. In particular, these findings suggest the need for a shift in focus from risk factors to machine learning-based risk algorithms. (PsycINFO Database Record

Risk factors for suicidal thoughts and behaviors: A meta-analysis of 50 years of research.

About one million suicides and ten million suicide attempts occur worldwide each year. Suicide is not simply a response to stress, but generally a complication of a psychiatric disorder. A proposed stress–diathesis model is described in clinical and neurobiological terms. Neurobiological correlates of the diathesis for suicidal acts point to the involvement of the serotonergic and noradrenergic systems, and the ventromedial prefrontal cortex. Some treatments seem to reduce suicide risk independently of an effect on the primary psychiatric disorder, perhaps by reducing the diathesis.

Neurobiology of suicidal behaviour.

In an earlier, separate study, the authors found that human aggression and suicide (a specific aggression-related behavior) were associated with lower levels of CSF 5-hydroxyindoleacetic acid (5-HIAA), a serotonin metabolite. That study focused on subjects with personality disorders without affective illness. In the present study they examine the life history of aggression and history of suicidal behavior in 12 subjects with borderline personality disorders without major affective disorder. Histories of aggressive behaviors and of suicide attempts were significantly associated with each other, and each was significantly associated with lower 5-HIAA levels. Altered serotonin metabolism may be a highly significant contributing factor to these behaviors in whatever diagnostic group they occur. Language: en

Aggression, suicide, and serotonin: relationships to CSF amine metabolites.

Sociopaths are “outstanding” members of society in two senses: politically, they draw our attention because of the inordinate amount of crime they commit, and psychologically, they hold our fascination because most ofus cannot fathom the cold, detached way they repeatedly harm and manipulate others. Proximate explanations from behavior genetics, child development, personality theory, learning theory, and social psychology describe a complex interaction of genetic and physiological risk factors with demographic and micro environmental variables that predispose a portion of the population to chronic antisocial behavior. More recent, evolutionary and game theoretic models have tried to present an ultimate explanation of sociopathy as the expression of a frequency-dependent life strategy which is selected, in dynamic equilibrium, in response to certain varying environmental circumstances. This paper tries to integrate the proximate, developmental models with the ultimate, evolutionary ones, suggesting that two developmentally different etiologies of sociopathy emerge from two different evolutionary mechanisms. Social strategies for minimizing the incidence of sociopathic behavior in modern society should consider the two different etiologies and the factors that contribute to them.

The sociobiology of sociopathy: An integrated evolutionary model

Six depressed patients free of recent serious suicidal ideation developed intense, violent suicidal preoccupation after 2-7 weeks of fluoxetine treatment. This state persisted for as little as 3 days to as long as 3 months after discontinuation of fluoxetine. None of these patients had ever experienced a similar state during treatment with any other psychotropic drug.

Emergence of intense suicidal preoccupation during fluoxetine treatment.

• Cerebrospinal fluid concentrations of the monoamine metabolites 5-hydroxyindoleacetic acid (5-HIAA), homovanillic acid (HVA), and 3-methoxy-4-hydroxyphenyl glycol (MHPG) were measured in 30 psychiatric patients who had attempted suicide and 45 healthy volunteers. The suicide attempters had a significantly lower CSF 5-HIAA level than the controls, especially those who had made more violent attempts. After adjustment for differences in body height and age between controls and patients, the difference in 5-HIAA level became even more marked. Concentrations of 5-HIAA also were lower than normal in suicidal patients who were not diagnosed as depressed at the time of lumbar puncture, while HVA levels were lowered only in the depressives. A follow-up study of these and 89 more patients (depressed and/or suicidal) revealed a 20% mortality by suicide within a year after lumbar puncture in patients with a CSF 5-HIAA level below the median.

https://jamanetwork.com/HttpHandlers/ArticlePdfHandler.ashx?journal=psych&articleId=492558&pdfFileName=archpsyc_38_6_002.pdf

Lars Sjüstrand

Papers

Monoamine metabolites in CSF and suicidal behavior.