INTEGRATIVE MODELS OF SUICIDAL BEHAVIOR

INTRODUCTION
Suicide is a major public health issue worldwide. Forecasts from the World Health Organization (WHO) estimate that by 2020, the global death toll from suicide will be an annual 1.54 million, with approximately 30 million suicide attempts per year . Current research in suicidology reveals the complex and multifaceted nature of this phenomenon, involving effects of social, psychopathological, neurobiological and hereditary factors occurring throughout the process of suicidal ideation to suicidal behavior. Suicidal behavior also remains the most serious emergency to confront mental health professionals, given the significant correlation of suicidal risk with psychiatric disorders . This article aims to review the most influential theoretical models and psychopathological mechanisms involved in suicidal behavior. The development of integrative theoretical constructs, combined with a multidimensional approach to suicidal risk factors, increase the odds of detecting and preventing suicidal behaviors in the general population, while also allowing for the possibility of new research on the topic.

THE SOCIOLOGICAL MODEL
Until the 19th century, suicide was considered to be a moral choice that contravened prevailing religious norms. Emile Durkheim’s ‘Le Suicide’, published in 1897, was the starting point for the scientific understanding of suicidal behavior. The sociological approach provided the first explanation to the various aspects of suicide, defining it as ”all cases of death resulting directly or indirectly from a positive or negative act of the victim himself, which he knows will produce this result”. Durkheim claimed that suicide is either the product of an excess, or comes about out of a lack of what is moral, economic or social in nature, classifying suicides by cause into egotistic, a n o m i c , a l t r u i s t i c a n d f a t a l i s t . D u r k h e i m ‘ s conceptualization has exerted a major influence on subsequent psychological approaches by highlighting the essential role of social factors and correlated beliefs and moral value .

PSYCHODYNAMIC MODELS
Sigmund Freud offered the first psychological explanation for suicide, describing it as an initially repressed desire of destroying another. Subsequently, by means of internalization of the object, the individual ends up turning his aggressive impulses against himself . Reflecting on Freud’s perspective, Jean-Michel Quinodoz concludes that ”the pleasure we derive from life must constantly be regained in the face of the tendency towards self-destruction” . Menninger extends Freud’s psychoanalytical explanation, by describing a triad of desires that precede the suicidal act: the desire to kill, the desire to be killed and the desire to die. After introjecting into his own ego the object towards which the individual is repressing his aggressive drives, the person experiences feelings of guilt for wanting others to die, then becomes depressed and hopeless, ultimately punishing himself through suicide. . Current psychoanalytical approaches describe thoughts, feelings and sensations that are attached to distorted cognitive-affective schemas about the self and others, resulting in excessive dependency or self-criticism. Suicidal ideation and behavior are are interpreted as attempts to cope with the helplessness and despair generated by feelings of failure or abandonment by the loved object. These often imply feelings of anger directed at first towards others, and then towards the self, desperate attempts to catch the attention of the absent object, fantasies of annihilating the abhorred parts of one’s self, or reuniting with lost or imaginary loved ones . Studies have confirmed the role played by dissociation , ego vulnerability , primitive object relationships and distorted self-representations within psychoanalytical constructs in suicide but more research is needed given existing methodological challenges in measuring and controlling variables.

PHENOMENOLOGICAL MODELS
Edwin Shneidman applied a phenomenological perspective of the structures of experience and consciousness to the topic of suicide. He defined it as a structure with two essential components, the first being the generally applicable dimension, which includes biological, social and philosophical factors, and the second being the subjective experience within the mind of every individual . Following this view, and as a result of his research work on suicide notes, Shneidman identified an overwhelming, unbearable pain suffered by the individual, which he termed psychache. This concept is intrinsically linked to the unmet, vital psychological needs of the individual. According to Shneidman, a person’s needs can be divided into modal needs, which define his personality within the intra-psychic and interpersonal daily functioning, and vital needs that can lead to suicide when they are not met (love, belongingness, a positive s e l f – i m a g e , c o n t r o l , s i g n i f i c a n t i n t e r p e r s o n a l relationships). Suicidal behavior occurs when the individual cannot stand the psychache anymore but there are, however, different individual thresholds of tolerance to this mental pain .
Comparable to Shneidman’s model, Roy Baumeister’s escape theory of suicide involves the breakout from the unbearable psychological pain that occurs prior to the suicidal act. According to Baumeister, suicidal behavior follows a specific sequence. At first, the discrepancy between one’s own expectations and actual results causes frustration. This state can be determined either by unrealistic standards or negative life events, and leads to feelings of guilt that is attributed exclusively to oneself. Subsequently, the individual becomes excessively self-aware, comparing himself to an ideal or remote self from the past. Thus, an intolerable negative affect is generated, which in turn causes the cognitive deconstruction of reality that implies focusing only on current moment, unpleasant experiences. According to Baumeister, this time distortion mechanism constitutes a defense mechanism that enables the individual to cognitively distance himself from past failures, but also from the anxiety generated by an unbearable, hopeless future. The process of cognitive deconstruction gradually determines a decreased capacity for impulse control, thus enabling the emergence of suicidal behavior. The escape theory provides an explanation for the individual going against his survival instinct and integrates the role of the cognitive processes in managing psychological pain .
Building on Baumeister’s conceptualization of suicide as an escape from psychological pain, Mark Williams offers a comprehensive cognitive model called the cry of pain model of suicide. This approach highlights s u i c i d a l i n d i v i d u a l s ‘ i n c r e a s e d s e n s i t i v i t y t o environmental cues that suggest defeat or humiliation. Consecutively, arises a strong need to escape, given the lack of any alternatives, as well as a feeling of hopelessness strengthened by the belief that the current circumstances will linger indefinitely . Williams’ model also integrates the ethological perspective of Gilbert and Allan, where defeat and entrapment are seen as suicidal risk factors by potentiating depression. Defeat is understood as the perception of a lost battle for one’s own status or identity, whereas captivity can be defined as the inability to move forward or to escape a certain situation. .

COGNITIVE MODELS
Aaron Beck began formulating his cognitive theory of suicide in 1967, following his studies on depressive disorders. He came to the conclusion that an individual’s own perceptions and interpretations are ultimately crucial in understanding his experiences and associated behaviors. Thus, Wenzel and Beck have introduced, in 2008, a cognitive model of suicidal behavior that comprises three fundamental dimensions: dispositional vulnerability factors, cognitive processes associated with psychiatric disturbance and cognitive processes associated with suicidal acts. The authors have identified five dispositional vulnerability factors in suicide: impulsivity and its related constructs, problem-solving deficits, an over general memory style, a trait-like maladaptive cognitive style and personality.
Impulsivity is, perhaps, one of the most well studied characteristics of populations with suicidal risk. The ways in which it increases the risk of self-harm are not, as yet, adequately understood. The lethality of suicide attempts generally correlates with planning, suggesting the absence of impulsivity. Conversely, impulsivity is associated, as a character trait, with serious or even lethal suicide attempts for patients with comorbid affective disorders. These results confirm the models of suicidal behavior that involve a certain degree of disinhibition even in the case of premeditated attempts, showing that impulsivity together with depression increase suicidal risk. Displaying impulsive suicidal behavior in correlation with environment factors also described in the diathesis-stress model.
Problem-solving deficits manifest themselves in suicidal individuals as a reduced capacity for generating solutions, a decreased capacity for using alternatives, estimating negative consequences to the proposed solutions and an increased likelihood of using denial or avoidance as defense mechanisms . Research has shown that cognitive rigidity and dichotomous thinking can also result in a deficient impersonal and inter-personal problem-solving abilities, by creating difficulties in generating alternate solutions. Furthermore, cognitive flexibility is seen as playing an integral role in the general executive function, allowing for a distinction between high and low lethality suicide attempts . Numerous studies have shown a significant relationship between different aspects of executive functioning (particularly the problem-solving ability) and stressful life events, depression, hopelessness and suicide .
An over general autobiography memory style can also influence problem-solving abilities in suicidal individuals because they have difficulty remembering the details of certain events, offering non-specific answers. This concept has been introduced by Williams in the study of suicidal behavior . According to the author, an over general memory style prolongs episodes of emotional disturbance, reduces the ability to solve interpersonal problems (because previous experiences cannot be used efficiently as coping strategies to current situations) and diminishes the individual’s ability to see the future in a certain way . Moreover, Wenzel and Beck concur that an over general memory style disturbs decision-making capabilities. The individuals’ perception of no escape results in exacerbated feelings of hopelessness and suicidal ideation.
The last two dispositional vulnerability factors that Wenzel and Beck have identified are a trait-like maladaptive cognitive style and personality. The former refers to the individual’s tendency to make decisions based on a cognitive distorted thought pattern (rigid, dichotomous thinking, rash decisions) that augments sensitivity to everyday stressors . Personality is also considered to be a dispositional risk factor for suicidal behavior, with multiple studies showing correlations between neuroticism, psychoticism and introversion, on one hand, and suicidal ideation and behavior, on the other . Other research has shown that having impossible to achieve expectations about oneself is another important vulnerability factor in suicide. In the literature, perfectionism has been the most widely studied personality trait with regards to suicide. The construct has been divided into self-oriented perfectionism (choosing and maintaining unrealistic standards for oneself), others- oriented perfectionism (expecting others to be perfect) and socially-prescribed perfectionism (the belief that others expect one to be perfect) . Out of these three types, socially-prescribed perfectionism and self-oriented perfectionism correlate most with suicidal behavior . Wenzel and Beck have even suggested that socially- prescribed perfectionism is a better predictor of suicidal ideation than depression and hopelessness. The authors have argued that, in addition to perfectionism, there are many other personality traits that influence suicide, overlapping with a trait-like maladaptive cognitive styles .
Cognitive processes associated with psychiatric disturbance refer both to maladaptive thought contents, as well as biased information processing, particular to multiple psychiatric symptoms and pathologies (anxiety disorders, substance abuse, personality disorders, schizophrenia) .
Cognitive processes associated with suicidal acts refer to the maladaptive cognitive contents and information processes believed to be present during a suicidal crisis. Wenzel and Beck have argued that, out of all the symptoms of depression, hopelessness is the most important risk factor involved in suicidal crisis. Moreover, research has shown that hopelessness correlates with suicidal behavior, independently of depression . A distinction is made in the literature between state and trait hopelessness. The former represents the level of hopelessness at one particular moment (e.g., during a suicidal crisis), whereas the latter refers to the level of an individual’s stable negative expectations . The research conducted thus far has shown that a stable level of hopelessness is an important predictor of suicide, Chronic, trait hopelessness can be seen as a type of suicide schema that, once activated by stress, induces cognitive processes that are also relevant to suicide. ,. Attentional fixation is another element described by Beck’s model with respect to cognitive disturbances associated with suicidal acts. Attentional fixation is a cognitive phenomenon that involves not only a narrowing of attention, as implied by Baumeister’s cognitive deconstruction, or Shneidman’s cognitive constriction, but also an exaggerated preoccupation with suicide as the only means to satisfy the individual’s needs.
Dispositional vulnerability factors and cognitive processes associated with psychiatric disturbance present as a distinct network for each individual. The greater the burden of these variables and stress factors, the higher the likelihood of suicidal behavior to occur. The cognitive model posits an integrative approach, allowing for further research of the dynamics of suicidal behavior.
Starting from Beck’s notion of hopelessness, David Lester suggested the complementary concept of helplessness. This can be useful in distinguishing individuals displaying hopelessness from those that seem to experience it but are mostly unable to take the necessary steps to overcome life predicaments. Lester also mentions the impostor phenomenon, as described by Harvey and Katz , as a type of cognitive schema for individuals with suicidal tendencies where they perceive themselves to be incompetent but are not actually so. Lester includes shame and lack of self-worth within the larger category of cognitive distortions, while highlighting their affective component .
Suicide’s significant correlation with depression entails research on the cognitive process of rumination. Smith, Alloy and Abramson have shown that a ruminative cognitive style can predict hopelessness and suicidal ideation . Other research conducted in this field has shown that rumination may be described and even prolonged by cognitive rigidity .
David Rudd enveloped the cognitive approaches by elaborating the Fluid Vulnerability Theory. Building on Beck’s definition of suicidal modes (cognitive, affective, behavioral, motivational, and physiological networks, interconnected and activated by internal and external factors) Rudd explains that the repeated triggering of suicidal modes causes a lowering of the activation threshold and an increase of future vulnerability to suicide. Individual vulnerability is influenced by cognitive susceptibilities (problem-solving deficits, attentional fixation, over general memory style, cognitive rigidity), biological susceptibilities (psychopathological symptoms characteristic on a Axis I disorder) and behavioral susceptibilities (lacking abilities in multiple domains, including interpersonal self-regulation and general emotional regulation) that are interdependent and interactive . The system is based on elements such as: a feeling of being unwanted (”I don’t deserve to live”), helplessness (”I can’t fix this problem”), lowered frustration tolerance (”I can’t bear this pain”) and perceiving one’s own life as a burden (”others would be better off if I were dead”) .
Marsha Linehan’s cognitive approach evaluates suicide risk by concentrating on identifying the protective factors that might guard against it. Linehan has shown that individuals with a history of suicidal behavior lack adaptive beliefs that prevent suicide and offer fewer Depressed bipolar patients have presented dysfunctions in several cognitive areas, such as attention (13, 34, 35), learning, memory (36, 37) and psychomotor speed (6, 38, 39).
The severity of the disorder also seems to be associated with cognitive deficits (6, 40). According to previous studies (21, 23, 24, 36, 41), chronic patients or patients with a history of multiple episodes and hospitalizations, present stronger cognitive deficits (6). The duration of the illness appears to interfere with attentional process and consequently, in the patients capacity to concentrate (6).
Little however is known about the presence of nature of cognitive deficit at the time of illness onset, nor its evolution throughout the course of illness (4). Results indicate that core neuropsychological deficit in sustained attention, learning and recall, spatial/nonverbal reasoning and several aspects of executive function are present at illness onset. Cognitive impairment in bipolar disorder are, thus, most likely not exclusively attributable to progressive decline associated with increased illness burden, cumulative treatment effects or chronicity of illness (5). Indeed, current conceptualizations posit that bipolar disorder is most likely characterized by both early and progressive dysfunction (5, 42, 43).
Elshahawi (14) showed that the earlier age of onset is associated with more declines in executive function and attention. The age of onset did not correlate significantly with total memory score, but showed a negative correlation with verbal memory and non verbal memory. Elshahawi (14) showed that later age of onset was inversely correlated with attention and executive function and this is consistent with Martinez-Aran (11). In contrast, El-Badri (44), Zubieta (27) and Deckersbach (25) did not find a significant correlation between age of onset and cognitive performance.
Mur (45) suggest that impaired executive function and loss of inhibition might be an important feature of bipolar disorder regardless of the severity of the disease or the effects of medication. Also, these executive- type cognitive traits may constitute and endophenotype for further studies on the ethiology of bipolar disorder. Psychotic symptoms were also described as having a significant impact on cognition, even when patients were examined in a first episode (6, 46).
R e c e n t s t u d i e s h a v e r e p o r t e d g r e a t e r neurocognitive impairment in euthymic bipolar disorder patients with a history of psychosis relative to patient without such a history (47). Psychosis has come into focus, as it often constitutes an important clinical marker for a more severe course of illness in bipolar disorder. Several authors found no differences between patients with and without a history of psychotic episodes. (47, 48,
49, 50, 51, 52) In contrast, Albus (53) reported an overall more compromised performance on cognitive measures in first-break patients who presented with psychotic symptoms. Similarly, Zubieta (27) found that patients with a history of psychosis obtained lower scores on measures of attention, verbal memory and executive functioning than healthy controls. Specific to executive functioning, Bora (54) concluded that deficits in cognitive flexibility may be the trait marker of psychotic features among patients with bipolar disorder. In the nonverbal domain of cognitive functioning, Glahn (55) reported significantly weaker performance on measures of spatial working memory in patients with a history of psychosis compared with patient without such a history (47).
Besides the influence of depressive and manic symptoms over cognition, it is reported that anxiety may affect cognitive function as well (56, 57). Bipolar disorder significantly co-occurs with anxiety disorders at rates that are higher than those in the general population (58) and the presence of the anxiety disorder (6, 59). Treatment of comorbid anxiety features may also help to improve apparent cognitive problems that might otherwise be misattributed to other aspects of psychopathology (1). While cognitive deficits are typically less pronounced than those found in other neurological or psychiatric illnesses (e.g. schizophrenia, Alzheimer dementia), reduced neuropsychological ability appears to significantly affect psychosocial functioning in bipolar patients (2).
Despite periods of symptomatic recovery, individuals with bipolar disorders often continue to experience impairments in psychosocial functioning, particularly occupational functioning (60). They do not regain premorbid level of occupational functioning even after mood episodes have resolved (61). Cognitive impairment has been associated with poor social and work performance even after long remission periods and controlling for subclinical mood symptoms (10, 16, 24, 27, 58). However, there are recent results suggesting that the functional disability may be restricted to a subgroup of cognitively impaired bipolar patients (6, 62).
Two determinants of psychosocial functioning of euthymic (neither fully depressed nor manic) individuals with bipolar disorder are residual depressive symptoms and cognitive impairment. (60) Rates of unemployment and disability among individuals with bipolar disorder are considerably higher in normal population (60, 63). Two- thirds of patient with bipolar disorder experience a moderate to severe impact of the illness on occupational functioning (60, 64). Following treatment for a mood episode many people remain functionally impaired during follow-up periods despite syndromal and/or symptomatic recovery (60, 65, 66, 67). In terms of work productivity, bipolar patients miss an average equivalent of 1 week of work every month due to missed days at work and impaired work performance (68). Various determinants of functioning in bipolar patients include depressive symptoms, early onset, more and longer recent hospitalizations, comorbidity, lower socio-economic status and poorer premorbid functioning (60, 69, 70). Based on a review of studies investigating functional outcomes in bipolar individuals Bauer (71) concluded that depressive symptoms appear to be the determinant most consistently related to lower overall psychosocial functioning (60, 71, 72, 73, 74, 75). Cognitive difficulties reported by individuals with bipolar disorder at work include sluggish thoughts, difficulties focusing, getting started on task, organizing complex task and managing multiple projects, difficulties remembering and becoming easily overwhelmed (60, 76, 77). Findings of Bearden (61) indicate that better neurocognitive function in multiple domains and improvement in these domains over time are strongly predictive of subsequent occupational recovery (61). Findings of Dickerson (79) indicate that current employment status was significantly associated with cognitive performance, especially immediate verbal memory, total symptom severity, history of psychiatric fewer reasons for staying alive than individuals without a history of suicide attempts . As seen through this perspective, reasons for staying alive can be considered personal and environmental contingencies that act against suicide. The author posits an integrative model of suicide by maintaining that paying attention to regulating emotional balance and environmental factors facilitates understanding and modifying suicidal behaviors in the long term through alternating strategies of acceptance and change. The theory is based on the fundamental principles of determinism. Although Linehan, building on Baumeister or Shneidman theories, has highlighted the importance of negative emotions in the origin of suicidal acts, the author enhances the models by integrating social context and its influence on regulating emotional balance .

DIATHESIS-STRESS MODELS
Schotte and Clum’s diathesis-stress model employs elements from other psychological theories , conceptualizing suicide as a solution due to the lack of alternatives and by highlighting interpersonal deficits. Cognitive rigidity in problem solving, owed to the influence of stressors, causes a predisposition for hopelessness and suicidal ideation. Individuals with a low cognitive ability for flexibility and generating alternate thoughts are unable to identify different solutions and tend to anticipate negative repercussions of the options considered. As a result of stress factors, hopelessness escalates, increasing thus the risk for suicidal behaviors .
John Mann develops a diathesis-stress model that posits psychiatric disorders and socio-demographic factors as triggering elements for suicidal ideation. The theory also supports the existence of a neurobiological backdrop for clinical characteristics of suicidal behavior. According to this model, impulsivity and aggressiveness are independently associated with suicidal behavior and low serotonergic functioning . Research has shown that serotonergic activity at the prefrontal cortex is involved in b e h a v i o r a l a n d c o g n i t i v e d i s i n h i b i t i o n , a n d aggressiveness through a control mechanism that operates independently of psychiatric disturbance . Hopelessness (or, pessimism, according to Mann) correlates neurobiologicaly with low levels of noradrenalin . Post-mortem examinations suggest that suicidal individuals have a low number of adrenergic neurons and within a stressful context, adrenergic hyperactivity connected with HPA axis hyperactivity causes the depletion of mediator, thus inducing hopelessness. The model also correlates attention and problem solving deficits present in individuals with suicidal tendencies and depressive disorders with the emotional regulation system modulated by structures in the prefrontal cortex, amygdala, and the anterior cingulate
. Mann’s diathesis-stress approach also involves a genetic component for suicidal behavior . Studies of subjects with a family history of suicide attempts suggest that behaviors may be inherited by means of a predisposition towards psychiatric disturbance and impulsivity/aggressiveness. These results cannot be solely attributed to a social imitation behavior in family clusters with a history of suicide . Mann concludes that suicide is a result of all psychiatric disturbances and acute psychosocial crises brought on by the emergence of clinical, neurobiological, socio-demographic and genetic factors.

THE INTERPERSONAL THEORY MODEL
Thomas Joiner’s Interpersonal Theory states that psychological and interpersonal factors converge in predicting the suicidal act, including both the wish to die, on the one hand, and the acquired capability for committing the act, on the other . Interpersonal theory takes into account not only psychological processes, but also the way that the individual relates to his social environment, by grouping suicidal risk factors according to the role they play in the genesis of ideation, and the capability to act on it. A completed suicide attempt requires three elements: perceived burdensomeness, thwarted belongingness and acquired capability for suicide. By delineating suicidal ideation from suicidal behaviors, Joiner highlights the need for acquiring the capability to commit the act. Thus, capability is defined as a diminished fear of dying, an elevated physical pain tolerance, habituation and opponent processes and a history of traumatizing experiences. Joiner describes perceived burdensomeness (”I am a burden”) as the liability that the individual feels he is imposing on others, as well as the affectively modulated self-hate concept. Liability may be influenced by factors such as being homeless, in jail, unemployed, ill, having a feeling that one is useless, unwanted, and that he is a burden for his family. Self-hate originates in a low self-esteem, self- blame and shame. The notion of thwarted belongingness also comprises two dimensions: loneliness (”I feel separated from others”) and the lack of mutual affective relationships (”I have no one to turn to and I don’t help others). Joiner’s hypothesis justifies the transition from passive suicidal ideation, determined by perceived burdensomeness and thwarted belongingness, to the desire to kill oneself by the juxtaposition of hopelessness. The acquired capability to act on suicide thoughts increases as the fear of death diminishes, with suicidal wishes escalating towards suicide intent. Subsequently, the elevated physical pain tolerance threshold produces fatal or violent suicide attempts . Joiner’s interpersonal model of suicide presents a significant advantage by offering quantifiable test variables for multidimensional processes involved in the progression of suicidal thoughts into suicidal behavior.

THE MOTIVATIONAL-VOLITIONAL MODEL
Rory O’Connor has also put forward a new, integrative, framework that includes biological, psychological and social factors, offering a theoretical grounding for constructs that are responsible for suicidal thoughts and their transition into suicidal behavior. O’Connor’s theory draws on the diathesis-stress model , Baumeister’s escape theory , Williams’ captivity model and Ajzen’s theory of planned behavior . According to the Integrated Motivational-Volitional (IMV) model, the evolution of suicidal behaviors begins with a pre- motivational stage (vulnerability factors, environment, life events), followed by a motivational stage (factors involved in the emergence of suicidal thought and intent), and concluding with a volitional stage (factors involved in converting from suicidal thought to the suicidal act). In the first stage, triggering factors overlap with predisposing factors triggering a transition to the motivational phase, thus generating the premises for a heightened susceptibility to feelings of defeat and entrapment.
Subsequently, following copping difficulties and problem solving, emerges a feeling of entrapment, which potentiated by motivational moderators (thwarted belongingness, perceived burdensomeness, attitudes, negative thoughts, lack of social support) leads to the emergence of suicidal thoughts and intent. The transition from thought and intent to suicidal behavior takes place through the intervention of volitional moderators (capability to act, impulsivity, planning, social imitation) in the final stage. O’Connor contributes with valuable empirical prospects to the assessment of suicidal behavior risk factors by integrating multiple psychological constructs into the IMV model with, while supporting the hypothesis that suicidal behavior can be triggered in the absence of psychiatric disturbance.

CONCLUSIONS
In recent years, a clear tendency has emerged towards studying suicide risk factors by integrating multiple sociological, psychological, clinical, situational, neurobiological and epigenetic variables in order to explain the process of suicidal thought and behavior. Psychodynamic theories have offered a comprehensive explanation to account for the intra-psychic processes involved in suicide, while lacking sufficient scientific evidence due to the ambiguity of the constructs and their non-transposable methodologies. Later, cognitive and psychological pain models have brought a valuable, empirical approach, concentrating either on vulnerability traits or on triggering factors for suicidal behavior. Diathesis-stress theories have also contributed significantly in the development of a multidimensional a p p r o a c h t o s u i c i d e b y i n t e g r a t i n g c l i n i c a l , neurobiological and epigenetic variables. W h i l e concepts do not completely overlap, enough empirical support is provided to analyze these suicide rick factors in an interactive and interdependent manner. Contemporary interpersonal and motivational-volitional models further synthetized existing knowledge and endorsed a dynamical perspective on the progression of suicidal thoughts into suicidal behavior, while including many quantifiable moderators with an increased potential for detecting suicidal risk. Thus, important advances can be currently achieved in suicidology by integrating these common approaches and replicating results through longitudinal research studies. A comprehensive model of suicidal processes based on pre-existing constructs and the interaction between social, psychopathological, neurobiological and hereditary factors, might have significant consequences for future research opportunities and the development of efficient suicide prevention strategies.

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