Abstract
The Strain Theory of Suicide and mental disorders proposes that psychological strains precede suicidal behaviors and psychiatric disorders. This study was designed to test the theory with a large sample of suicide notes collected from Tasmania, Australia. The content of 261 suicide notes was analyzed for the presence of four psychological strains. It was found that 39.6% of the 261 suicide notes had at least one of the four psychological strains, with aspiration and coping strains being the most prevalent. We then compared the ratings of psychological strains with ratings of thwarted belonging and perceived burdensomeness and found that the presence of aspiration strain and coping strain was associated with thwarted belonging, while aspiration and deprivation strains were associated with perceived burdensomeness.
To elucidate the etiology of suicide, Zhang (2005) formulated a Strain Theory of Suicide. A strain consists of at least two stressors that pull the individual in different directions, resulting in frustration and anger which, in turn, leads to suicidal behavior. The Strain Theory of Suicide is based on the theoretical frameworks established by previous sociologists, including Durkheim (1897/1951), Merton (1957), and Agnew (1992, 2006), and on cognitive dissonance theory (Aronson, 1998; Festinger, 1957). Cognitive dissonance is a feeling of discomfort caused by holding two or more inconsistent cognitions. For example, you like to smoke cigarettes, but you also do not want to die from cancer. The presence of cognitive dissonance motivates people to reduce the dissonance. For example, the person can try to quit smoking or refuse to believe the research shows that smoking increases the risk of cancer. Psychological strain is a feeling of discomfort, frustration, anger, and even psychological pain, much stronger than cognitive dissonance and is much more likely to result in psychiatric symptoms and suicidal behavior.
Psychological strains may come from four major sources (Zhang, Wieczorek, Conwell, & Tu, 2011):
Value strain can result from (a) traditionalism versus modernity in the status of women, (b) traditionalism versus modernity in love and marriage, (c) Eastern versus Western values, and (d) collectivism versus individualism. Aspiration strain, in which individuals may have high aspirations and goals for themselves, but reality may force them to settle for less, can result from (a) choice of marriage partner, (b) educational attainment, (c) career, and (d) social and political achievements. Deprivation strain occurs when those in a society who are economically poor are aware of others from similar backgrounds who are living better lives (the strain is between one’s own less than ideal life and the perceived wealth of others). This can result from (a) low income compared with others, (b) a lack of educational opportunities, and (c) poor employment options. Coping strain, which refers to the inability of people to cope with the crises and the problems that they face, can result from any crisis, including (a) job loss, (b) loss of face, (c) loss of loved ones, (d) failure at school, or (e) loss of money (investments) or property. Crises in themselves do not involve strain, but only when the individual cannot cope with the negative life events.
Zhang et al. (2014; Zhang & Lyu, 2014) devised an inventory to measure these four strains in individuals. In samples of Chinese and American college students, scores on these four strains were positively associated with measures of trait anxiety, depression, and suicidal ideation. The more the strain is experienced, the higher the level of psychopathology (such as depression, anxiety, and suicidal behavior).
Most research on suicidal behavior typically studies only one theory of suicide. This study sought to compare the roles of two theories, Strain Theory and Joiner’s Interpersonal Theory of Suicide, which has been the focus of a great of research in recent years. Joiner (2005) proposed an Interpersonal Theory of Suicide that asserts that three elements must be present in order for suicidal behavior to occur: two motivations for suicide and the capacity for self-harm. The motivation for suicide is comprised of two components: thwarted belongingness and perceived burdensomeness. Thwarted belongingness is a sense of social alienation or a failure to form close social bonds, while perceived burdensomeness is the sense that one is a burden on those around you. Together these two elements create the motivational force for suicidal behavior. In addition to being motivated for suicide, the capacity for engaging in a self-destructive act must also be present. This requires a lowered fear of death, elevated tolerance for physical pain, and habituation arising from past experiences such as childhood abuse, combat exposure, and previous self-destructive behavior (Van Orden et al., 2010).
Van Orden and colleagues (2006) tested his theory in a sample of 343 outpatients at a psychological clinic. A self-report measure of perceived burdensomeness was associated with suicidal ideation and a history of attempted suicide even after controlling for hopelessness. In a sample of 73 Mexican American outpatient females, Garza and Pettit (2010) found that self-reported perceived burdensomeness was associated with an interview measure of suicidal ideation.
The purpose of this study was to examine the presence of the four types of strain in a large sample of suicide notes and to examine whether the presence of these strains was associated with the two motivational components of Joiner’s theory (thwarted belongingness and perceived burdensomeness). The hypothesis guiding the study is that psychological strains are the etiological factors for suicide, explaining why an individual becomes suicidal, while perceived burdensomeness and thwarted belongingness are the mediating factors between strains and suicidality. It is also possible that role of some sources of strain may be impacted by age and sex.
Method
The suicide notes (N = 261) were obtained from Tasmania, Australia, with the permission of the coroners (Gunn, Lester, Haines, & Williams, 2012). The sample was 24.5% female and 75.4% male. (The sex of one suicide was not listed.) The mean age was 41.8 (standard deviation = 17.1; range: 12–86). The most common methods for suicide were guns (n = 98), solids and liquids (n = 63), and gas (n = 42). Previous research on these notes reported that those who left suicide notes in Tasmania during this time period differed from those who did not leave notes in being more often involved in interpersonal conflicts, less often psychiatrically disturbed, and less likely to be under medical supervision (Haines, Williams, & Lester, 2011). Those who left suicide notes were significantly younger than those who did not (41.2 vs. 44.4, standard deviations = 16.9 and 18.0, t1037 = 2.74, two-tailed p = .006).
Gunn et al. (2012) had judges rate these notes for the presence of the themes of thwarted belongingness and perceived burdensomeness. These ratings were used for this study. Two different judges from those by Gunn et al. rated the presence or absence of the psychological strains which minimized the possibility of experimenter bias.
The two new judges were graduate students who learned the Strain Theory of Suicide and who were trained in coding the presence or absence of the strains. They worked independently of each other and were not allowed to communicate with each other before the ratings were finished. The results of each judge are presented separated in order to provide evidence for the reliability of the results. Table 1 reports the ratings of the two judges on each of the four strains based on their understanding of the Strain Theory of Suicide. Cohen’s κ coefficient is a statistic which measures interrater agreement for qualitative (categorical) items. It is generally thought to be a more robust measure than simple percentage agreement calculation. κ assumes its theoretical maximum value of 1 only when both observers distribute codes identically. Scores from 0.40 to 0.60 can be considered moderate agreement, and scores above 0.60 are excellent (Landis & Koch, 1977). It can be seen in Table 1 that the interrater agreement was excellent for value, aspiration, and coping strains and moderate for deprivation strain. The statistical analyses, primarily Pearson correlations, were performed with SPSS.
Psychological Strain Ratings by the Two Judges.
Results
As shown in Table 1 and averaging the scores of the two judges, value strain was present in 1.9% of the suicide notes, aspiration strain in 12.4%, deprivation strain in 4.3%, and coping strain in 26.0%. No notes had all four strains, 0.7% had three strains, 34.3% had one strain, and 60.4% had no strains.
As noted in the Methods section, the notes have previously been rated for the presence versus absence of the themes of perceived burdensomeness and thwarted belongingness (Gunn et al., 2012). In the present set of suicide notes, thwarted belongingness was present in 30.2% of the notes, while perceived burdensomeness was present in 10.2% of the notes. (Both were present in only 4.2% of the notes.) The associations between the ratings of strains in the suicide notes and the measures of thwarted belonging and perceived burdensomeness are shown in Table 2. It can be seen that the presence of aspiration strain and coping strain was associated with thwarted belonging, while aspiration and deprivation strains were associated with perceived burdensomeness.
Association Between Psychological Strains, Thwarted Belonging, and Burdensomeness.
Note. *p < .05. **p < .01.
There were no associations between sex and the presence of strains in the content of the notes (see Table 2). However, older suicides were less likely to indicate aspiration strain (Point biserial r for the two judges −.15 [two-tailed p < .05] and −.19 [p < .01]).
Discussion
In this study, we identified psychological strains in 39.6% of the 261 suicide notes. The degree and type of strain varied by age. Furthermore, there were associations between the presence of psychological strains and the variables proposed by the Interpersonal Theory of Suicide (Joiner, 2005), thwarted belongingness, and perceived burdensomeness.
Thwarted belongingness was positively associated with the presence of aspiration and coping strains, whereas perceived burdensomeness was positively associated with deprivation strain. This suggests possible mediating variables in the relationships that Joiner (2005) proposed between suicidal behavior and thwarted belongingness and perceived burdensomeness. While the Strain Theory of Suicide explores the original reason why a person considers suicide, Joiner’s Interpersonal Theory of Suicide offers constructs that explain why suicidal ideation leads to suicidal behavior. For example, thwarted belongingness results from frustrated social support, and perceived burdensomeness from being a burden to others, but not everyone with these states becomes suicidal. Strain theory proposes that a critical first step is the presence of strain. Between the path from strains to suicidal actions, thwarted belongingness and perceived burdensomeness are moderators that increase the risk of suicide when they are strong and reduce the risk of suicide when they are weak.
Much research into suicidal behavior examines only one theory of suicide. By examining the relevance of two theories of suicide in this study (Strain Theory and the Interpersonal Theory of Suicide), we have found that both contribute to an understanding of suicidal behavior. Future research is needed to investigate the different roles of the predictors formulated by the two theories.
The findings of this study have implications for both suicide prevention and future research. People are generally aware of the role that stress plays in their lives, and they are typically advised to reduce stress by various means, such as exercise and meditation, People are not generally aware of strain (two stressors which pull the individual in different directions, resulting in frustration and anger). Strain reduction through general education, skills training, and counseling, starting at an early age, could be effective in reducing psychological distress. Those counseling suicidal individuals, or individuals who are at risk of suicide, might look also for signs of strain so that they can provide tactics for coping with strain.
One limitation of the study is of the use of suicide notes. By using suicide notes (rather than, e.g., psychological autopsies 1 ), we lack information on suicides who do not leave suicide notes, typically the majority of suicides (75%–80%), and so we cannot generalize the present findings to all suicides. The present research was conducted on Australian suicide notes and needs to be replicated in other countries and cultures in order to explore the generality of the findings.
Footnotes
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The research was supported by the U.S. National Institute of Mental Health: R01 MH068560 to Dr. Zhang.