In several countries suicidality in prison is the leading cause of death (1–5). This phenomenon is not necessarily linked to incarceration. In many countries, including Hungary, the number of completed suicides and attempted suicides during incarceration is extremely low (6–8). However, the incarcerated population is significantly more at risk of suicide during their entire life history: among prisoners 8.6% of men (95% CI 6.1-11.2) and 12.2% of women (95% CI 7.1-17.3) attempt suicide over the course of a lifetime, compared with 2.7% in general population (9). It could mean that prisoners belonged to a risk group even before incarceration, and that the risk of suicide attempts also can be increased even after release. This disparity highlights the crucial need to understand the factors contributing to the high rates of suicide attempts, thereby facilitating the establishment of appropriate screening procedures and interventions.

Meta-analyses (2, 4) have identified key risk factors associated with suicide attempts and self-harm among incarcerated individuals, including factors preceding suicide, comorbid mental disorders, single-person cell placement, lack of visits, abuse during incarceration, violent offenses, life sentences, and remand. The strongest clinical factors associated with an increased risk of suicide include current or recent suicidal ideation, which raises the likelihood of suicide by over ten times. Additionally, a history of previous non-suicidal self-injury (NSSI) or suicide attempts (SA) represents an eight-fold risk (2, 4).

Prisoners are exposed to heightened levels of chronic stress, stemming from interpersonal, financial, and legal factors. The emotionally taxing nature of prison life necessitates effective coping mechanisms, often leading to the development of adjustment and mental disorders (10, 11). The chronic stress factors affecting prisoners often precede the time of imprisonment, they are often exposed to childhood and adult traumas (abandonment, emotional, physical or sexual traumas as well) (12). During incarceration, prisoners face stressors such as the possible disruption of partner and family relationships, lack of social support, being assaulted; having major financial difficulties or institutional conflicts with other inmates or staff (10). The primary concerns can manifest as substance-related and addictive disorders, impulsivity-related conditions such as personality disorders, impulse control disorders, and major depression (13–18). Despite the elevated incidence of mental disorders among incarcerated individuals, coupled with their heightened vulnerability, healthcare resources in this context remain limited (13).

Several theories and research have investigated the risk factors of suicide in the general population. One of the most comprehensive models for suicide attempts is the integrated motivational-volitional (IMV) model of suicidal behavior by O’Connor and Kirtley (19). The model underscores vulnerability to suicide across three phases: pre-motivation, motivation, and action. The pre-motivation phase considers diathesis, environmental factors, and early life events that underlie suicidal ideation. The motivation phase centers on entrapment due to failure and humiliation, influenced by variables affecting self-regulation. The action phase involves transitioning from thought to suicide attempt, influenced by access to means, pain sensitivity, and impulsivity (19).

Additionally, various models delve into the complexities of NSSI. The cognitive-emotional model (20) posits that emotional reactivity, mental representation of self-harm, negative self-representations, and thoughts related to NSSI contribute to it as a maladaptive coping strategy. Similarly, the four-function model (21) describes processes maintaining NSSI through automatic/social and negative/positive reinforcement, primarily serving intrapersonal functions, such as emotion regulation and reducing negative emotional states. Furthermore, the cognitive-emotional reactivity model (22) integrates insights from recurrent depression, applying them to borderline personality disorder, where maladaptive coping strategies like self-harm reinforce connections between negative thoughts, emotions, and bodily sensations. Therefore, NSSI becomes more and more automatic because of the repetitions.

Research has investigated the potential similarities between SA, NSSI, and behavioral addictions (23–28). This concept challenges traditional views and suggests that considering recurrent suicidal behavior as an addiction could transform treatment approaches, perhaps comparing them with approaches typically used for substance addiction.

Behavioral addictions are triggered by specific patterns and involve compulsive engagement in a particular activity, despite negative consequences. It should be mentioned that these addictions are not officially recognized in the DSM-5. Unlike substance addictions, behavioral addictions are defined by behaviors that become overwhelmingly dominant in an individual’s life, profoundly impacting their daily functioning, physical and mental health, and the surrounding environment (29). While this classification remains a subject of ongoing debate among experts, numerous studies have unearthed intriguing connections that warrant exploration.

The addictive model of self-harming behavior by Blasco-Fontecilla, Fernández-Fernández (25) emphasizes that individuals with frequent SA or NSSI (≥5 attempts in a lifetime) may be considered behavioral addicts. The recurrence of self-harm and SA is primarily linked to negative emotions, such as relieving emptiness or helplessness seeking attention. This model suggests common neurobiological mechanisms, including the involvement of the mesocorticolimbic reward system and the release of endogenous opioids, shared between self-harm and addiction. Both self-harm and addiction provide relief from psychological pain and activate the stress and opioid systems. Similarly to addiction, self-harming behaviors may become more persistent and severe over time. Self-harm can sensitize individuals to suicidal thoughts and behaviors, making them more susceptible to triggering by stressful life events. There is also a risk of relapse in both self-harm and addiction, often precipitated by similar life events (25).

The urge to self-harm in individuals with NSSI parallels addictive features (30), including increased repetition, impulsivity, rumination, and withdrawal symptoms (24, 25, 31). Higher scores at the addictive features subscale of the Ottawa Self-Injury Inventory are associated with greater distress over urges to self-injure, and also with more frequent and severe NSSI (28). Analyzing the language used in forum posts related to NSSI, Himelein-Wachowiak, Giorgi (27) found that over 75% of the users in their sample fulfilled a minimum of two NSSI-adapted diagnostic criteria of substance use disorders in their posts.

Adolescent studies on NSSI also found addictive features, displaying an underlying urge, increasing severity and frequency, difficulty in stopping self-harming behavior, and relief after self-harm (26). High impulsivity and emotional dysregulation were identified as major risk factors for self-harm, leading to the characterization of certain elements of self-harm as behavioral addiction (32). Childhood abuses and traumas were frequently observed among adolescents with NSSI, and three out of five psychiatric outpatients exhibited addictive features in their self-harming behavior, often co-occurring with other substance or behavioral addictions (33).

Our study examines the connection between traditional addiction concepts and the understanding of suicidal behavior as an addiction. It explores the implications of this connection specifically within the incarcerated population.

Suicidality in prison is a major issue, with incarcerated individuals showing higher lifetime suicide attempt rates compared to the general population (9). This study explores the connection between suicidality and behavioral addictions, highlighting that recurrent suicidal behavior may function similarly to addiction. Both behaviors involve negative emotions, provide psychological relief, and can become more persistent over time (23–28). This addiction-like nature of suicidality indicates shared neurobiological mechanisms (25) and highlights the need for targeted interventions within the incarcerated population.

Our multicentre cross-sectional study involved 363 incarcerated individuals. At the study’s outset, a standardized Hungarian questionnaire for assessing suicide or NSSI as behavioral addictions was unavailable, and questions regarding addiction posed challenges during the correctional institutions’ approval process. Therefore, we assessed the behavioral addiction approach indirectly. We deliberately chose measurement tools—assessing depression, cognitive-emotional regulation, impulsivity, mindfulness skills, perceived stress, and lifetime incidents of self-harm and suicide attempts—to capture multifaceted aspects of suicidal behavior among inmates. These instruments are suitable for assessing both suicidal behavior and the underlying psychological mechanisms of behavioral addiction. The datasheet on SA and NSSI helped assess the frequency and severity of suicidal behaviors. Although inmates could provide open-ended responses for triggers, this method proved unreliable, and the data were not analyzed. A semi-structured interview would likely be more effective. Negative emotions such as emptiness or helplessness and elevated stress levels are primary triggers for both self-harm and addiction (19, 22, 25). To assess these, we administered the BDI-S and PSS4. The PAYKEL scale provides information on suicidal thoughts, plans, and intentions, central to the second phase of the IMV model (19) in understanding suicidal behavior. From the perspective of behavioral addictions, it offers insights into craving. High impulsivity and emotional dysregulation increase the risk of self-harm, sharing addictive features such as repetition, difficulty stopping, and relief after self-harm. These factors contribute to the persistence and severity of suicidal behaviors, like substance addiction, especially in individuals with a history of trauma or abuse (30–33). These factors relate to the third phase of the IMV model, turning ideas into action (19). To assess these factors, we used the BIS-S-8, CERQ, and FFMQ.

The analysis revealed the prevalence of mild depression, moderate suicidal ideation, and impulsivity, coupled with a notable history of suicide attempts and self-harm among our sample, underscores the urgent need for tailored interventions. Our findings align with the addiction model, which posits that frequent engagement in suicidal behaviors sensitizes individuals to heightened suicidal ideation during stressful periods. This sensitization mirrors the craving concept in substance addictions, highlighting a potential neurobiological basis shared between behavioral and substance dependencies. We observed a prevalence of mild depression, moderate suicide thoughts, moderate impulsivity, and slightly increased perceived stress in the sample. Furthermore, particularly high percentage of the inmates in our sample attempted suicide or committed non-suicidal self-harm during their life history. Nearly half (43.3%) of the participants attempted suicide at least once. This rate is significantly higher than the approximately 10% reported in large sample studies (9), and also it represents an increased risk for suicidal behavior based on the motivation phase of the IMV model of suicidal behavior (19). According to Hungarian data, this phase usually does not turn into the action phase during detention. Based on 2020 data, the completed suicide rate is 0.36 per 100.000 inmates in Hungarian prisons (8), which is among the lowest rates globally (47). Based on the IMV model, this indicates that the system sets a suitable limit for access to the means and that suicide attempts cannot take place under controlled conditions. However, after release, the possibility of access to means increases, as well as impulsive behavior would be controlled less, so the likelihood of suicidal behavior may increase also. The Hungarian example confirms that restrictive actions and control are extremely important in reducing suicidal behavior during detention, however the deeper understanding of motivational factors can also help to reduce the occurrence of later suicidal behavior.

We hypothesized that major repetition (at least 5 times during life history) of suicide attempts (SA) or non-suicidal self-injury (NSSI) would represent a distinct suicidal among repeaters. Our binary logistic analysis did not confirm this hypothesis, but certain trends were identified ( Tables 3 , 4 ). A more frequent history of SA in the past (Model 1-3) correlated with a heightened manifestation of suicidal ideation in the present. This result is consistent with the addiction approach, which suggests that more frequent suicidal behavior sensitizes individuals to later suicidal thoughts in stressful life events (25). The elevated level of suicidal ideation involved not only a cognitive aspect but also an urge and planning, as defined by the Paykel Suicidal Thoughts Scale. This characteristic is comparable to cravings in addictions (24–26, 28, 31). Additionally, individuals engaging in repeated SA exhibited lower levels of non-adaptive emotion regulation strategies (Model 2). Suggesting that suicidal behavior may serve an emotion regulation function, particularly accentuated in those with more frequent attempts. Suicide behavior, in this context, may be distinguished from cognitive emotion regulation strategies, potentially taking precedence as a maladaptive coping mechanism.

Regarding NSSI (Model 4-6), similar tendencies in suicidal thinking were observed, but without noticeable differences in emotion regulation strategies. Conversely, perceived stress levels increased, both in the relationship between self-injurious and non-self-injurious individuals and with an escalation in the number of self-injuries in their life history. This could suggest a diminished level of frustration tolerance in those reporting more frequent self-harm. It is crucial to emphasize that these differences are subtle and indicative of trends, warranting further investigation.

Hierarchical regression models ( Figures 1 , 2 ) supported the addictive model of suicidal behavior. At comparable levels of perceived stress or depression, inmates with a history of more frequent NSSI or SA reported a higher frequency of suicidal thoughts than those with less frequent suicidal behavior throughout their life history. Low distress tolerance or frustration tolerance are also key factors of substance or behavioral addiction. The difficulty in sustaining negative emotions plays an important role not only in the development of addictive disorders but also in their maintenance and relapses (48, 49). This finding aligns also with the sensitization theory of the addiction approach, suggesting that repeated suicidal behavior may affect neurobiological mechanisms related to stress and relief systems (25).

After release the risk of suicide among former inmates can be seven times higher than in general population (50), that is why it is very important to identify the factors that may be risk factors for later suicide, even during detention. Understanding this aspect is particularly crucial for prisoners, as incarceration often limits access to means and opportunities for suicide, despite the elevated stress levels they may experience (10), inmates are under controlled conditions. However, upon release, this controlled environment dissolves, significantly amplifying the risk of suicide, especially for those who previously relied on this kind of maladaptive emotion regulation patterns. Based on our results, severe repeater inmates are at a higher risk of future suicide attempts. They exhibit a behavioral pattern that resembles addiction, suggesting that their suicidal behavior could be interpreted as a form of dependence. In their cases even minor stressors or depressive episodes can substantially escalate suicidal ideation during the post-release period. The addiction perspective can assist in their treatment, with a focus on addressing specific behavioral and cognitive patterns.

The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.

The studies involving humans were approved by Research Ethics Committee of Semmelweis University (TUKEB number: 92/2015) Directorate of the Hungarian Prison Service Headquarters. The studies were conducted in accordance with the local legislation and institutional requirements. The participants provided their written informed consent to participate in this study.

IHP: Conceptualization, Data curation, Investigation, Project administration, Validation, Writing – original draft. SzK: Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Validation, Visualization, Writing – original draft, Writing – review & editing. TSz: Data curation, Formal analysis, Methodology, Validation, Visualization, Writing – original draft. ÁZ-G: Conceptualization, Validation, Writing – original draft. DP-F: Conceptualization, Funding acquisition, Project administration, Resources, Supervision, Validation, Writing – review & editing.