This is the first national study to examine the prevalence and characteristics of firesetting in the US general population. We found that: 1) the prevalence of firesetting in the general population is about 1%; 2) individuals with a lifetime history of firesetting, even those without ASPD, are more likely than the individuals without a history of firesetting to engage in other antisocial behaviors; 3) almost all individuals with a lifetime history of firesetting have lifetime or current psychiatric comorbidity (even when those with ASPD were excluded from the analysis); and 4) approximately half of the individuals with lifetime history of firesetting have used mental health services at some point of their lives, more than threefold the rate in individuals without a history of firesetting.
Confirming results from clinical samples11
, we found that individuals with a history of firesetting were more likely than those without history of firesetting to be male, young and never married. Gender differences may be due a greater rate of impulsivity and risk-taking behaviors among men, 34, 35
while the relationship of lifetime history firesetting and young age in this study may indicate a birth cohort effect of the youngest group, a recall bias of remote events, or higher mortality of firesetters in the oldest age group.36
Although about 60% of cases of firesettings occurred before age 15, almost 40% of the cases persisted after that age.
In accord with previous research in clinical samples, 11, 13, 37, 38
we found that individuals with a history of firesetting were significantly more likely to have other psychiatric disorders associated with impaired impulse control, such as substance use disorders, bipolar disorder, pathological gambling, and ASPD even after adjusting for other psychiatric disorders. Dysthymia and anxiety disorders had the weakest association with firesetting in this study. Although obsessive compulsive disorder (OCD) was not assessed in the NESARC, obsessive-compulsive personality disorder (OCPD) was. Firesetting was significantly associated with OCPD, but its association with ASPD was much stronger, suggesting that firesetting may be closer to disorders of impulsivity than to obsessive-compulsive spectrum disorders. These findings are supported by the strong association of firesetting with other antisocial behaviors reported in this study. Overall, these data are consistent with prior research indicating that antisocial behavior, substance use, and impulsivity share a common underlying vulnerability.39–41
These findings suggest that firesetting may be better understood as a behavioral manifestation of a broader impaired control syndrome and part of the externalizing spectrum rather than the internalizing spectrum disorders.
The finding that a lifetime history of firesetting and a family history of antisocial behaviors, even in the absence of ASPD diagnosis, is strongly associated with a history of other antisocial behaviors and substantial axis I comorbidity, raises questions about the current conceptualization of ASPD. About one half of the individuals with a lifetime history of firesetting met criteria for ASPD. Removal of those individuals from the analysis diminished the strength, but did not alter the direction or significance of our findings regarding psychiatric comorbidity, associated antisocial behaviors or treatment seeking (data available upon request). Consistent with the recommendations of the DSM-V Research Planning Nomenclature Work Group to conduct research on dimensional models of existing typologies42, 43
and specifically on the conceptualization of ASPD44, 45
and on the broader category of externalizing disorders,39, 45
our findings suggest that antisocial behaviors tend to be strongly associated with each other and increase the risk of lifetime and current psychiatric disorders, even in the absence of a DSM-IV diagnosis of APSD. These findings underscore the importance of antisocial syndromes of behaviors currently considered subthreshold. There may be certain nosological advantages of a dimensional rather than categorical conceptualization of ASPD. Future research should examine clinical, research and policy-making utility of dimensional, categorical or a combination of both approaches to better define ASPD and the implications of selecting specific diagnostic thresholds.
Our study also identified higher rates of lifetime and past year treatment utilization across a broad range of service settings. Respondents in the NESARC study were not specifically asked whether they sought treatment for other reasons but rather if they sought treatment for any Axis I disorder. Based on prior reports1
, it appears that very few individuals seek treatment for firesetting, and, when they seek treatment for other reasons, they are rarely queried about their history of firesetting behavior. Given the high rates of comorbidity, disability and treatment utilization of individuals with a lifetime history of firesetting documented in this study, it seems important to screen for history of firesetting among psychiatric patients.
This study has the limitations common to most large-scale surveys. First, information was based on self-report, potentially resulting in over- or underestimation of the true rates of firesetting. The NESARC did not examine the reliability of individual items. However, the ASPD module of the AUDADIS, which contained the firesetting questions, had a kappa=0.67, which compares favorably with other standardized assessments of ASPD.29
Furthermore, the reliability of the ASPD module, as measured by Cronbach α, is 0.86, and does not change whether or not the firesetting questions are included in the calculation, supporting the reliability of the firesetting questions. Third, because the NESARC sample only included civilian households and quarters populations, information on individuals in prison, who may have higher rates of firesetting, were unavailable. Fourth, frequency, severity and the negative consequences of firesetting were not assessed, leaving the possibility that the behavior occurred only once in the individual’s life and/or may not have resulted in substantive damages. Even with this broad definition, the results of the study suggest that a lifetime history of firesetting is strongly associated with high rates of psychopathology and treatment seeking. At present, little is known about firesetting or pyromania in the general population. Longitudinal data are needed to examine the course of firesetting and to distinguish individuals with firesetting from those who develop pyromania. Differences between individuals who set fires and those with the diagnosis could inform on the need of a broader definition of DSM-IV pyromania. Fifth, Wave 1 of the NESARC did not include data on Borderline Personality Disorder or ADHD, both of which are associated with high levels of impulsivity. Finally, because the questions about firesetting were embedded in the ASPD module, the associations detected in this study could have been better explained as correlates of ASPD. However, removal of individuals with ASPD did not change the pattern of associations, suggesting that our findings reflect true associations with firesetting. Future research should evaluate whether the associations found in this study could be also be explained as correlates of pyromania.
Despite these limitations, our study constitutes a critical step improving the understanding of the prevalence and characteristics of firesetting behavior in the US. The study found high rates of other antisocial behaviors and comorbidity with externalizing spectrum disorders in a large nationally representative sample of the general population. Given the legal and social consequences of firesetting, its associated disability and high rates of treatment-seeking, and its cost to society, the results of this study suggest that more attention may be needed to address the needs of individuals with a history of firesetting.