This study showed that, generally, women are more likely to commit suicide via self-immolation. Several factors are reported as risk factors for self-immolation, the most important of which are domestic violence and stressful events such as family conflicts. Most of the self-immolation victims had a history of psychiatric disorders, were less educated, and were married. Studies performed in various regions of Iran have reported different rates for self-immolation. These studies reported higher rates in the western and northern parts of Iran and border provinces. Self-immolation is a significant social and medical problem all around the world. Suicide by self-immolation is more frequent in developing (40.3% of all suicides) than the developed countries (0.06% - 1% of all suicides). It comprises 0.37% to 40% of total burn center admissions worldwide, and, in Iran, it ranges from 4.1% to 36.6% (
5,
18).
Self-immolation is the fourth leading cause of death and the sixth leading cause of disability among people aged 15 to 44 years (
1,
5).
The mean age of self-immolation victims in Iran is relatively low compared to the western countries (
12). Studies have shown that the mean age of self-immolators in the world is one decade older than the corresponding age in Iran (
44,
45). Several factors contribute to this issue, including arranged marriage and children’s wedding (
8,
10,
18,
41,
46-
49). A review study performed in Iran has reported that in border provinces, which have higher rates of self-immolation than other regions of the country, family size (5.2 versus 4.1; P < 0.05) and age at first marriage are significantly different than the national averages (P < 0.05) (
14).
The results of studies on suicidal patterns about gender differences are controversial. In the present study, self-immolation was more common among females. In contrast to Iran, studies conducted in Australia and North America have shown that men committed self-immolation more than women (
50,
51). This difference might be due to the fact that self-immolation is considered as a method of crying for help by women in some regions of Iran (
21).
Previous studies conducted in Iran and other developing countries have reported an inverse association between self-immolation and level of education (
18). Also, those with lower levels of education tend to use more violent methods for suicide, which can be attributed to poor problem-solving skills (
8). Moreover, a low level of education is usually associated with lower socio-economic status (
11).
There are studies that mentioned socio-economic status as an important factor that contributes to self-immolation in less developed countries, which is in line with findings of the present study, that most of the female self-immolators were from low socio-economic classes. Deprivation, poverty, and humiliation in Uzbekistan, problems related to marriage and trousseau in India, and arranged marriage in Afghanistan have been reported as the main causes of attempting self-immolation by young women (
52-
54).
In Iran, self-immolation is more a cultural issue rather than a religious (
8). Similar to other studies, Iranian studies have also reported that there are cultural factors that increase the risk of self-immolation, including imitative acts by women who imitate self-immolation threats from their peers and sisters (
8,
18). Both socio-cultural and psychiatric factors have been found to be associated with self-immolation (
10). Easy access to inflammable materials may have an important role in committing suicide by self-immolation; Kerosene is the most commonly used tool (85%) for self-immolation (
12).
Domestic violence is reported to be associated with self-immolation. Family conflicts, intimate relationship break-ups, divorce, and financial issues might also have a similar role (
14,
34). Arranged marriage, unwanted pregnancy, being financially dependent on the husband, unfair divorce laws, unemployment, and limited job opportunities for women may bring social hopelessness in women. In this context, suicidal behaviors may be an automatic reflection, particularly in the first years of married life for women (
5,
9,
24). Similar cultural factors might contribute to self-immolation in different provinces of Iran. The results of studies conducted in East Azerbaijan (
41), Mazandaran (
10), Kohgiluyeh-and-Boyer-Ahmad (
48), Kurdistan (
36), Ilam (
6,
19), Kermanshah (
18), Tehran (
55,
56), Khuzestan (
57), Lorestan (
33), and Sistan-and-Baluchestan (
24) suggest that tension with husband and his family has a crucial role in women’s deciding to commit self-immolation. Economic opportunities are often lower in border provinces of Iran, and, therefore, their unemployment rate is higher than the national average. Moreover, people of these provinces are usually more illiterate, suffer from higher rates of psychological distress, and have limited access to health facilities. Furthermore, in these regions, divorce is associated with a high stigma, and women feel uncertain about their future. Overall, studies have shown that almost all border areas of Iran suffer from a high prevalence of self-immolation, compared to central regions of the country. Future studies are needed to elaborate on this phenomenon and understand its underlying mechanism. Self-immolation in Iran particularly affects young married women living in rural areas (
8,
41,
47,
48,
58), and 73% of self-immolation cases occur in families with physical or verbal aggression (
24).
The findings of the present revealed that although mental disorders may contribute to deciding to commit suicide, but social and cultural issues seem to better predict self-immolation. This finding is somehow inconsistent with studies conducted in western countries, in which major depressive disorder, psychosis, alcoholism, and drug use disorders were strongly associated with suicide (
59-
63).
In many countries, self-immolation is a type of radical political protest. For example, during the “Arab Spring” in recent years (
64). Our review revealed no association between a particular political challenge and self-immolation in Iran. The present study had limitations. First of all, due to the limitation of data, we couldn’t perform a meta-analysis. Also, there were differences between the included studies concerning the sampling method, data collection instruments, and methods applied to assess the outcomes. We limited the data collection process to studies performed on women in Iran.