Attempting suicide changes the brain?

Introduction

In this brief article we posit a rationale as to why a past clinical history of attempted suicide is a strong risk factor for suicide. We hypothesise that the process of making a suicide attempt, with the clear intention of dying, fundamentally alters the brain and that this increases the likelihood of considering suicide in the future.

Suicide Risk Factors

Amongst the many risk factors for suicide, a past history of a suicide attempt increases the likelihood of further attempts by 8-fold (Parra-Uribe et al., 2017; Bostwick et al., 2016). In addition, there are many other factors which increase the ‘risk’ of future suicide e.g. being male, engaging in substance misuse and having a mental illness, in particular a mood disorder (Bostwick et al., 2016), but none are as predictive as having a history of a previous attempt. This is thought to be because having gone through the process of contemplating and then attempting suicide, the individual has revisited the thinking involved in this process and this ‘rehearsal’ consolidates their thoughts at some level – such that when similar precipitants present once again e.g. they become depressed, they are more likely to reconsider suicide as an option. Another reason is that the circumstances that contribute to suicide, e.g. illness and loss, are often extreme and are unlikely to have immediately and fully resolved following a suicide attempt, and so the ‘risk’ of suicide remains relatively high.

However, in practice, the period between suicide attempts can vary considerably, and often years can pass between an attempt and subsequent suicide. This somewhat argues against the rehearsal explanation or the possibility that the factors contributing to suicide remain unchanged and causally active. This is why we proffer an alternative explanation, that not only allows for rehearsal and predisposing factors to play a significant role, but also explains how the impact is long-lasting and many months and even years can pass between attempts, and between an attempt and subsequent suicide.

Attempting Suicide Alters the Brain

Along the lines of the rehearsal explanation we propose that the brain is fundamentally altered by the process of seriously contemplating and then attempting suicide. This is because the process that leads to suicide involves the appraisal of many critical factors, including the evaluation of one’s self worth, one’s relationships with others, and one’s current situation in life. Distancing oneself from these attachments and deciding to actively take one’s life is a very significant step. It involves breaking connections with vital elements within one’s life, and thus life itself. We postulate that this is mirrored by ‘neural breakages’ that result in reorganisation of brain circuitry involved in the generation of self and its relations. Preliminary functional neuroimaging evidence supports this hypothesis, and has shown that neural networks in depressed individuals that have attempted suicide are discernibly different when compared to those that are depressed but have not attempted suicide (Malhi et al., 2019a; Malhi et al., 2019b). This is logical. Suicide is an extremely traumatic act. It is understandable that it may cause damage to the brain, at least functionally, if not structurally, and that like other traumas it imprints brain function and alters neural processes. The precise nature of these changes, in particular their severity and the degree to which they disrupt normal brain function; and what happens to them over time, needs to be determined. But the finding that the brain is altered, and possibly irreversibly so, by the process of attempting suicide is of immense importance clinically, and perhaps even more so because of potential implications for future research.

Suicide: A Process

An essential first step towards better understanding the mechanisms of suicide is to appreciate that suicide is not an event per se but the culmination of a ‘process’; one that may have begun a long time before the act of suicide itself (Malhi et al., 2018). Figure 1 illustrates the various components of a model that we have proposed for suicide in the context of mood disorders. It shows that the process essentially begins with appraisal (and reappraisal), and that prior neurobiological and neurocognitive factors, and in particular negative cognitions that occur as part of mood disorders, create a state of defeat and entrapment, which then generates suicidal ideation. At each step, many factors can drive the process forward whilst at the same time rescue factors can prevent progression. In this model, the development of suicidal ideation is important, but it is the development of intent that is critical in triggering a suicide attempt. The model clearly illustrates that preventing attempts once intent has crystallised is a belated measure that is difficult to implement because of a very limited window of opportunity, and that instead the process should ideally be interrupted much earlier.

Figure 1.

Suicide Model. This model outlines the process that leads to suicide and includes contributing factors that drive the progression through different stages. Neurobiological and neurocognitive factors that may have been impacted by genetic (e.g. familial loading) or environmental (e.g. trauma) factors impact upon the individual’s appraisal system. This system entails appraisal of one’s self, one’s situation and others and is valenced either positively or negatively, with the latter potentially resulting in a sense of defeat and entrapment and thus progressing the suicide process. When this sense of defeat and entrapment increases, especially within the context of thwarted belongingness, perceived burdensomeness or humiliation, the desire to escape arises and suicidal ideation develops. Rescue factors at this stage entail awareness of problematic thoughts and reframing these to facilitate rescue. Within suicidal ideation, the presence of psychic pain and a sense of hopelessness further increase the need for escape and suicide becomes a viable means by which to achieve this. At this ideation stage, if help and social support are sought and received then ideation can be minimised. However, if psychic pain continues, the chance of relief from this pain drives the crystallisation of suicide intent, which when combined with volitional factors leads to a suicide attempt. Volitional factors that facilitate a suicide attempt include disposition and capability. When suicide capability is high, and the individual has the disposition to attempt, and if the individual has access to means, then a suicide attempt is likely. The main rescue factors at the intent stage of the process are the individual’s attachments to others in their life, and their religious beliefs that may prohibit suicide. At the subsequent attempt stage of the suicide process the rescue factors entail the removal of access or the implementation of effective barriers to means.

Naturally, moving systematically through the ‘steps’ in the suicide process is likely to enhance subsequent re-engagement of the process during future episodes of depression – supporting in part the rehearsal explanation as to why the probability of suicide in the context of a mood disorder is increased by having a history of a past attempt. Similarly, a failed attempt is unlikely to meaningfully alter many of the factors that contributed to the prevailing cognitions that propagate the suicide process, and so once again a recent history of an attempt is likely to increase the risk of future suicide. However, the impact of a suicide attempt is much broader, and we argue that it changes not only the self, situational, and relational factors but also, more fundamentally, it alters neurocognitive factors and the neurobiology of the brain. Furthermore, these changes are longer lasting and perhaps even permanent – explaining why the enhancement of risk associated with having survived a suicide attempt is seemingly lifelong.

Implications for Suicide Research

Suicide research has been stymied by an inherent inaccessibility to patients experiencing suicidal ideation because by their very nature many suicidal thoughts are transitory. Furthermore, suicide is largely considered to be an event and the focus of research has centred on risk factors and not the process of suicide itself. In addition, many of the ethical concerns regarding suicide research are valid and given that 40% of individuals attempting suicide manage to do so to completion on their very first attempt – a significant proportion of the population that needs to be investigated and better understood is lost to inquiry.

However, counter to the prevailing view that regards suicide essentially as a sporadic event, we have expatiated upon the psychological processes that lead to suicide, and thus emphasise that it should be modelled not as an incident but rather as a process. This has some immediate implications that are beneficial for research. For instance, modelling suicide as a process allows for dissection of the various ‘steps’ involved - detailed examination of which is likely to provide a deeper understanding of the mechanisms that lead to suicide. Furthermore, understanding these mechanisms may uncover potential targets for treatment that can halt or reverse the suicide process at various points. The proposed model also creates opportunities for the investigation of both psychological and pharmacological interventions, and arguably this is an improvement over current approaches such as containment, which do not lend themselves to mechanistic research to the same extent

The other key implication for research emerges from the hypothesis that the trauma of a suicide attempt alters the brain fundamentally, and that this alters its functioning, in particular in relation to future suicidal ideation. Put another way, the brains of those that have attempted suicide are forever modified and therefore research needs to consider this possibility when sampling and grouping patients for the purposes of investigation. This means that patients who have attempted suicide are a distinct population that is separate from those that have never attempted suicide, and that because their brain function has been significantly altered, the neural and cognitive models that govern suicidal thinking in these individuals will also be different.

Conclusion

In this brief piece we have put forward an idea that has strong theoretical underpinnings and some promising preliminary support. The hypothesis clearly needs to be corroborated and developed further, both theoretically and empirically, and to facilitate this we have shared this concept with the aim of providing an impetus for mechanistic suicide research that may yield clinical advancements based on deeper pathophysiological understanding of the processes that underpin this modern-day plague.