The role of military identity in substance use and mental health outcomes among U.S. Army Reserve and National Guard Soldiers

ABSTRACT

We investigated how military identity (i.e., veteran identity centrality—the extent to which military service is central to an individual’s sense of self) relates to substance use and mental health among U.S. Army Reserve and National Guard (USAR/NG) soldiers. Data were drawn from Operation: SAFETY, a longitudinal survey study of USAR/NG soldiers. Regression models (n = 413 soldiers) examined relationships between military identity and substance use (i.e., alcohol problems, past 3-months non-medical use of prescription drugs (NMUPD), illicit drug use, tobacco use), and mental health (i.e., generalized anxiety, anger, depression, and PTSD), controlling for sex, race, age, education, years of military service, military status (current/former), and deployment (ever/never). In adjusted models, stronger military identity was not related to alcohol, illicit drug, or tobacco use, but was associated with past 3-months NMUPD (OR: 1.40, 95% CI: 1.12, 1.75, p < .01) and greater symptoms of anger (IRR: 1.02, 95% CI: 1.01, 1.03, p < .01), generalized anxiety (IRR: 1.05, 95% CI: 1.01, 1.10, p < .01), depression (IRR: 1.06, 95% CI: 1.02, 1.10, p < .01), and PTSD (IRR: 1.07, 95% CI: 1.02, 1.12, p < .01). The findings demonstrate the importance of military identity for health-related outcomes. NMUPD suggests potential self-medication and avoidance of help-seeking, as admitting difficulties may conflict with military identity.

What is the public significance of this article?—Our results demonstrate that stronger military identity is associated with past 3-months non-medical use of prescription drugs and greater mental health symptoms. While military identity may not cause these problems, stronger military identity in the presence of these problems, may contribute to greater symptoms, symptom persistence, or inhibited treatment-seeking. Future research is needed to identify ways in which interventions can integrate and address the possible role of identity-related challenges.

Introduction

An extensive body of research has examined factors related to physical and behavioral health outcomes among military service members. However, limited attention has been given to the role of identity, and specifically military identity, in contributing to these outcomes. Military identity, rather than being merely of sociological or psychological interest, may also have direct implications for understanding individuals’ health outcomes (Griffith, 2011). Researchers have speculated that the conflict service members and veterans may experience between their military and civilian identities in and of itself may contribute to mental health problems (Smith & True, 2014). Further, common features of military identity, such as masculine traits of emotional suppression, self-reliance, and value on strength and aggression, may limit help-seeking for emotional and mental health challenges (Lorber & Garcia, 2010).

Few studies have examined this empirically, but emerging evidence suggests that military identity among veterans is tied to greater difficulties with PTSD (Orazem et al., 2016) and depression (Di Leone et al., 2016), as well as choices about seeking healthcare through the Veterans Health Administration system (VA) and feelings of belonging at the VA (Di Leone et al., 2016). A recent examination of military identity in veterans in a sample of community veterans (more than half of whom were Vietnam era) found that stronger military-related identity was protective against suicide ideation but increased the risk for alcohol problems, indicating that military-related identity may impact health in complex and multi-directional ways (Adams et al., 2019). Qualitative studies examining military identity discuss the complexity of individuals’ experiences, as they relate to reintegration and participation in multiple civilian contexts (e.g.,Demers, 2013; Hammond, 2016; Vest, 2013; Woodward & Jenkings, 2011) but only connect these experiences to health outcomes in limited cases (e.g., Smith & True, 2014). There is a need for more empirical quantitative evidence identifying relationships between conceptualizations of military identity and outcomes of importance, such as mental health and substance use, and understanding how interventions and treatments can better integrate and address the role of identity.

Reserve and National Guard members may relate to military identity differently due to the unique conditions of their part-time military service. Reserve military members belong in both civilian and military worlds at the same time and continually transition between them (Lomsky-Feder et al., 2008). As a result, both civilian and military identities are present and may be variably salient at different times depending upon the individuals’ experiences and social context (Griffith, 2009). Qualitative evidence suggests that National Guard members see their identity along a continuum from civilian to military, alternate between which identity is most important, and their military identity overall may be seen as secondary to their civilian identity (Vest, 2013). Deployment experience, in particular, may be a key factor for understanding how reservists conceptualize their military identity. Reservists with deployment experience often described how this renders the military identity stronger (Vest, 2013) and reservists who have not deployed may be susceptible to negative emotions resulting from reduced feelings of belonging (Hoopsick, Homish, Bartone et al., 2018; Hoopsick, Homish, Vest et al., 2018). Further, compared to active duty soldiers, reservists may be at greater risk for experiencing problems with mental health and substance use (Cohen et al., 2015; Milliken et al., 2007; Thomas et al., 2010). This suggests that military identity and its relationship to potential health outcomes may be different for reserve and National Guard soldiers, compared to active duty service members, and merits further attention.

Given these gaps and the limited attention to identity overall, the goal of the current study was to investigate how military identity (and specifically veteran identity centrality; or the extent to which having served in the military is central to an individual’s sense of self) relates to substance use and mental health outcomes among a sample of U.S. Army Reserve and National Guard soldiers.

Methods

A subset of data was drawn from Operation: SAFETY (Soldiers and Families Excelling Through the Years), an ongoing longitudinal survey study of U.S. Army Reserve and National Guard (USAR/NG) soldiers and their spouses (n = 418 couples). All study procedures were reviewed and approved by the Institutional Review Board at the University at Buffalo, the Army Human Research Protections Office, Office of the Chief, Army Reserve, and the Adjutant General of the National Guard. The current study uses a subset of data collected from current and former soldiers who responded to questions about military identity at the fourth timepoint of the Operation: SAFETY study (n= 413 individuals).

Participants and procedures

Detailed study recruitment and data collection procedures have been published elsewhere (Devonish et al., 2017; Heavey et al., 2017; Vest et al., 2017, 2018). In brief, participants were recruited during drill weekends from Army Reserve and National Guard units across New York State and screened for eligibility. To enroll in the study, at least one partner needed to be currently serving in the USAR/NG at the time of the baseline survey and both partners had to be willing to participate. Both partners complete annual surveys covering a broad range of topics. The current analysis uses demographic data from the baseline assessment and predictor and outcome variables drawn from the fourth annual survey.

Measures

Military identity

Military identity was assessed using the Veteran Identity Centrality Scale, which assesses the extent to which serving in the military is central to an individual’s identity (Di Leone et al., 2016). The scale consists of five items rated on a 5-point Likert scale. Participants indicate agreement with the following statements: “Being in/having served in the military is a central part of who I am,” “My status in the military/as a veteran is rarely on my mind,” “I relate best to others who have served/are serving,” “I feel more connected to civilians than to others who are serving/have served,” and “I spend most of my time with military members/veterans.” Scores are summed up, such that higher scores signify greater veteran identity centrality (alpha: 0.70).

Alcohol problems

We used the Alcohol Use Disorders Identification Test (AUDIT; Babor et al., 2001; Saunders et al., 1993) to assess alcohol problems. The AUDIT includes 10 items rated on a 4-point scale from 0 (Never) to 4 (Daily or almost daily), with scores ranging from 0 to 40. Items include things such as “Have you or someone else been injured because of your drinking?,” and “How often during the last year have you had a feeling of guilt or remorse after drinking?” (alpha: 0.78).

Drug use

Non-medical use of prescription drugs (NMUPD) and illicit drug use were assessed using the NIDA Modified ASSIST (WHO Assist Working Group, 2002). This measure assesses lifetime and past 3-months use of illicit drugs, including marijuana, opiates, cocaine, hallucinogens, inhalants, methamphetamines, and other illegal drugs, as well as non-medical use of prescription stimulants, sedatives or sleeping pills, prescription pain medications, and other prescription medications. Use was defined as a positive response to use of any of the listed substances in the past 3 months (1 = any, 0 = none).

Tobacco use

Participants indicated whether they were currently using any of the following tobacco products: cigarettes, cigars, or smokeless tobacco.

Anger

Symptoms of anger were assessed using the PROMIS Anger scale (Pilkonis et al., 2011), an 8-item self-rated measure of anger over the past 7 days (alpha: 0.94). It is scored on a 5-point scale ranging from 1 (Never) to 5 (Always) (range: 8 to 40); greater scores indicate greater anger. Example items include, “I was irritated more than people knew,” “I felt annoyed,” and “I felt angry.”

Depression

Symptoms of depression were assessed with the Patient Health Questionnaire 8 (PHQ-8; Kroenke et al., 2009). The PHQ-8 measures symptoms over the past 2 weeks with eight items that range from 0 (Not at all) to 3 (Nearly every day). Higher scores indicate greater depressive symptoms (alpha: 0.91) and map onto the DSM-IV diagnosis for depression.

Generalized Anxiety

Anxiety was assessed with 10 items from the Severity Measure for Generalized Anxiety Disorder-Adult (Craske et al., 2013). The items examine symptoms of anxiety over the past 7 days on a 5-point scale ranging from 0 (Never) to 4 (All of the time) with higher scores indicating greater severity of anxiety. Example items include, “I felt uneasy” and “I felt nervous” (alpha: 0.91).

Post-traumatic stress disorder (PTSD)

Symptoms of PTSD were assessed with the PTSD Checklist, based upon DSM-5 (Weathers et al., 2013). This is a 20-item self-report measure of PTSD symptoms over the past month; greater scores indicate greater severity of PTSD. Each response is rated on a 5-point Likert-type scale ranging from 0 (Not at all) to 4 (Extremely), with an overall range of 0–80 (alpha: 0.95). This version has been adapted from the original version to specifically map back to DSM-5 (Bovin et al., 2016).

Deployment

Participants’ deployment history was dichotomized into ever deployed vs. never deployed, accounting for their responses to questions about deployment at baseline, and each of the subsequent follow-up surveys.

Military status

Participants’ military status was dichotomized into current vs. former soldier, accounting for their responses to questions about military service at baseline, and each of the subsequent follow-up surveys.

Years of military service

Participants reported their total years of military service, across all branches, at the baseline assessment.

Demographic characteristics

Demographics included in the models as covariates included sex, age, race, and educational level as reported by participants at the baseline assessment.

Analytic plan

Key variables of interest were first examined descriptively to characterize sample means and prevalence. Next, regression models examined the cross-sectional relationship between veteran identity centrality and four mental health outcomes (generalized anxiety, anger, depression, and PTSD) and several measures of substance use (alcohol problems, past 3-months non-medical use of prescription drugs, past 3-months illicit drug use, and current tobacco use), separately. Generalized anxiety, anger, depression, PTSD, and alcohol problems are all limited range count outcomes; therefore, negative binomial regression models were used because of their ability to account for the overdispersion in the count-based outcomes (Gardner et al., 1995). Logistic regression models were used for the dichotomous outcomes (NMUPD, illicit drug use, tobacco use). Adjusted models controlled for sex, age, race, education, years of military service, military status (current/former soldier), and deployment (ever/never). All analyses were conducted using Stata Statistical Software: Release 16.1 (Statacorp 2019. College Station, TX: StataCorp LLC.)

Results

Descriptive results

Soldiers in this analysis were 78.0% (n = 322) male and 22.0% (n = 91) female with a mean age of 31.8 years (standard deviation: 6.5; Table 1). On average, soldiers had served 9.4 years in the military (SD: 6.1) and 60.7% (n = 250) of participants had deployed at least once; the remainder had never deployed. Most (70%; n = 289) soldiers were currently serving in the USAR or the NG and 30% (n = 124) were separated from military service. Most participants were enlisted in rank (85.5%; n = 342) and 14.5% (n = 58) were officers. The majority of the sample was non-Hispanic White (81.7%; n = 331) and 89% had completed some college or had a college degree.

Table 1.

Participant demographics and descriptive characteristics of male and female soldiers (N = 413).

	Total, N = 413
Demographic Characteristics	% (n) or M(SD)
Age, years	31.8 (6.5)
Sex Male Female	78.0 (322) 22.0 (91)
Race/Ethnicity Non-Hispanic White Non-Hispanic Black Hispanic Other	81.7 (331) 4.9 (20) 8.6 (35) 4.7 (19)
Education High School Some College College Degree+	10.2 (42) 57.1 (236) 32.7 (135)
Military Service, years	9.4 (6.1)
Military Status Current Service Member Former Service Member	70 (289) 30 (124)
Ever Deployed (% Yes)	60.7 (250)
Military Identity
Veteran Identity Centrality	17.3 (3.4)
Mental Health
Anger	18.0 (7.0)
Generalized Anxiety	5.1 (6.8)
Depression	3.8 (4.8)
PTSD	10.1 (14.2)
Substance Use
Alcohol Problems (AUDIT)	4.8 (4.7)
Past 3-mos. NMUPD	3.7 (15)
Past 3-mos. Illicit Drug Use	7.4 (30)
Current Tobacco Use	29.4 (120)

The mean veteran identity centrality score (hereafter: military identity) was 17.3 (SD: 3.4; Table 1). The mean AUDIT score was 4.8 (SD: 4.7). Seventy-five or 18.4% of the soldiers had an AUDIT score >8, indicative of potentially problematic drinking. In terms of drug use, 3.7% reported past 3-months NMUPD and 7.4% reported past 3-months illicit drug use. The mean anger score was 18.0 (SD: 7.0), suggesting participants in our sample had more symptoms of anger, on average, compared to the general population (Pilkonis et al., 2011). The mean generalized anxiety score was 5.1 (SD: 6.8); 55% of participants reported mild anxiety with 18.4% indicating moderate to severe generalized anxiety. The mean depression score was 3.8 (SD: 4.8), and 30.7% of participants met criteria for mild or worse depression. Finally, the mean PTSD scores were 10.1 (SD: 14.2); overall 8% (n = 32) of the participants met criteria for a probable diagnosis of PTSD. Table 2 presents the correlation coefficients and significance levels for all variables included in the models.

Table 2.

Spearman correlations between model variables.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16
1. Alcohol problems
2. NMUPD	0.10
3. Illicit drug use	0.20***	0.00
4. Tobacco use	0.11*	0.01	0.04
5. Anger	0.14**	0.10*	0.11*	0.08
6. Generalized Anxiety	0.22***	0.21***	0.16**	0.08	0.66***
7. Depression	0.15**	0.20***	0.17***	0.09	0.57***	0.65***
8. PTSD	0.21***	0.18***	0.18***	0.15**	0.63***	0.77***	0.74***
9. Military identity	−0.03	0.16**	−0.10	0.06	0.14**	0.20***	0.15**	0.23***
10. Sex	−0.12*	−0.06	−0.01	−0.16**	0.10*	0.13**	0.13*	0.08	−0.12*
11. Yrs of military service	−0.06	0.10*	−0.13*	0.01	0.03	0.02	0.01	0.03	0.33***	−0.22***
12. Deployment (ever/never)	0.03	0.03	−0.09	0.04	0.05	0.07	0.03	0.08	0.35***	−0.26***	0.60***
13. Military status (current/former)	−0.04	0.04	0.18***	0.02	0.08	0.08	0.07	0.04	−0.22***	0.15**	−0.24***	−0.15**
14. Age	−0.16**	0.04	−0.13**	0.02	−0.00	0.00	−0.00	−0.01	0.27***	−0.11*	0.67***	0.36***	−0.14**
15. Race	−0.05	0.03	0.01	−0.06	−0.08	−0.02	−0.02	0.01	−0.02	−0.02	−0.05	−0.04	0.02	−0.03
16. Education	−0.03	0.02	−0.02	−0.17***	−0.05	−0.05	−0.05	−.10*	−0.03	0.12*	0.09	−0.00	−0.05	−0.15**	−0.01

Notes: PTSD = posttraumatic stress disorder; NMUPD = non-medical use of prescription drugs.

*p < .05, **p < .01, ***p < .001

Unadjusted results

Unadjusted models examining the relationship between military identity and mental health and substance use outcomes revealed several important relationships (Table 3). Military identity was not significantly associated with alcohol problems or tobacco use (ps > .05). However, stronger military identity was associated with greater odds of past 3-months NMUPD (OR: 1.26, 95% CI: 1.05, 1.52, p < .05) but reduced odds of past 3-months illicit drug use (OR: 0.90, 95% CI: 0.81, 0.99, p < .05). Stronger military identity was also associated with greater symptoms of anger (IRR: 1.01, 95% CI: 1.01, 1.02, p < .05), generalized anxiety (IRR: 1.04, 95% CI: 1.01, 1.08, p < .05), and PTSD (IRR: 1.06, 95% CI: 1.02, 1.10, p < .01). There was no significant relationship between military identity and depression in the unadjusted models.

Table 3.

Unadjusted and adjusted regression models of the association between military identity and substance use and mental health.

	Alcohol Problems IRR 95% CI		Past 3-Months NMUPD OR 95% CI		Past 3-Months Illicit Drug OR 95% CI		Current Tobacco OR 95% CI		Anger IRR 95% CI		Generalized Anxiety IRR 95% CI		Depression IRR 95% CI		PTSD IRR 95% CI
	Unadjusted	Adjusted	Unadjusted	Adjusted	Unadjusted	Adjusted	Unadjusted	Adjusted	Unadjusted	Adjusted	Unadjusted	Adjusted	Unadjusted	Adjusted	Unadjusted	Adjusted
Military identity	0.99 (0.97, 1.01)	0.98 (0.96, 1.00)	1.26* (1.05, 1.52)	1.40** (1.12, 1.75)	0.90* (0.81, 0.99)	0.96 (0.85, 1.08)	1.04 (0.98, 1.11)	1.04 (0.97, 1.12)	1.01* (1.01, 1.02)	1.02** (1.01, 1.03)	1.04* (1.01, 1.08)	1.05* (1.01, 1.10)	1.04 (1.00, 1.07)	1.06** (1.02, 1.10)	1.06** (1.02, 1.10)	1.07** (1.02, 1.12)
Sex		0.81 (0.65, 1.01)		0.34 (0.04, 2.87)		0.72 (0.27, 1.88)		0.42** (0.22, 0.81)		1.13* (1.03, 1.24)		1.49* (1.04, 2.13)		1.62* (1.12, 2.34)		1.37 (0.91, 2.06)
Years of military service		1.00 (0.98, 1.03)		1.14 (0.96, 1.34)		0.98 (0.87, 1.09)		0.98 (0.92, 1.04)		1.01 (1.00, 1.02)		1.02 (0.99, 1.06)		1.02 (0.98, 1.06)		1.03 (0.99, 1.07)
Deployment history		1.19 (0.96, 1.48)		0.53 (0.13, 2.23)		0.75 (0.29, 1.90)		1.10 (0.62, 1.92)		1.01 (0.92, 1.11)		0.95 (0.67, 1.36)		1.03 (0.72, 1.48)		0.97 (0.65, 1.45)
Military status		0.92 (0.76, 1.12)		2.65 (0.79, 8.87)		3.46** (1.55, 7.74)		1.26 (0.76, 2.09)		1.11* (1.02, 1.21)		1.31 (0.95, 1.79)		1.38 (1.00, 1.90)		1.28 (0.90, 1.82)
Age		0.98* (0.96, 0.99)		0.92 (0.79, 1.08)		0.97 (0.89, 1.05)		1.02 (0.97, 1.07)		0.99 (0.98, 1.00)		0.99 (0.96, 1.02)		0.99 (0.96, 1.02)		0.98 (0.95, 1.01)
Race		0.96 (0.86, 1.06)		1.47 (0.85, 2.56)		0.92 (0.57, 1.50)		0.88 (0.66, 1.16)		0.97 (0.92, 1.01)		1.05 (0.89, 1.24)		0.97 (0.82, 1.15)		1.06 (0.88, 1.28)
Education		0.91 (0.79, 1.05)		1.41 (0.54, 3.67)		0.96 (0.51, 1.83)		0.58** (0.40, 0.84)		0.96 (0.90, 1.02)		0.92 (0.73, 1.17)		0.90 (0.70, 1.15)		0.84 (0.64, 1.11)

Notes: Adjusted models controlled for sex (0 = male, 1 = female), deployment history (0 = never deployed, 1 = ever deployed), military status (1 = current soldier, 2 = former soldier), years of military service, age, race (1 = non-Hispanic White, 2 = non-Hispanic Black, 3 = Hispanic, 4 = other), and education (1 = less than high school, 2 = high school diploma, 3 = some college, 4 = college degree or more).

IRR = incident rate ratio; OR = odds ratio; CI = confidence interval; NMUPD = non-medical use of prescription drugs; PTSD = posttraumatic stress disorder.

*p < .05; **p < .01, ***p < .001

Adjusted results

In adjusted models controlling for sex, age, race, education, years of service, military status (current vs. former) and deployment (ever vs. never), stronger military identity was associated with a greater likelihood of past 3-months NMUPD (OR: 1.40, 95% CI: 1.12, 1.75, p < .01; Table 3). Further, stronger military identity was also associated with greater symptoms of all the mental health outcomes: anger (IRR: 1.02, 95% CI: 1.01, 1.03, p < .01), generalized anxiety (IRR: 1.05, 95% CI: 1.01, 1.10, p < .05), depression (IRR: 1.06, 95% CI: 1.02, 1.10, p < .01), and PTSD (IRR: 1.07, 95% CI: 1.02, 1.12, p < .01). Military identity was not significantly associated with alcohol problems, illicit drug use, or tobacco use in adjusted models.

Discussion

Overall, our results demonstrate that stronger military identity is cross-sectionally associated with greater odds of past 3-months NMUPD and greater symptoms of anger, generalized anxiety, depression, and PTSD. These findings provide empirical support for qualitative observations of the importance of considering military identity as a contributing factor in soldiers’ health outcomes.

As the centrality of military identity increased, soldiers were more likely to also report higher levels of mental health symptoms. This aligns with previous work which found that stronger military identity related to PTSD and depression symptomatology among female veterans (Di Leone et al., 2016). Qualitative evidence also suggests that attention to identity adjustment is important for mental health; individuals with stronger military identities may struggle to reintegrate into civilian life and reconcile their military and civilian identities (Orazem et al., 2016; Smith & True, 2014). Existing evidence is inconsistent, however, a more recent study, using a 3-item measure of identity centrality, found no relationship between identity and current depression or PTSD (Adams et al., 2019). However, it is important to note that a majority of this sample were older Vietnam-era veterans; the relationships between military identity and mental health outcomes may be different for different service cohorts and may vary depending on the length of time since military service. Identity conflicts may be more salient for current reservists or recent veterans, during the time of transitions between military and civilian life and roles (Vest, 2013).

Our study found no relationship between military identity and alcohol problems, although a previous study of military identity among older veterans did find that stronger identity was related to greater likelihood of alcohol use (Adams et al., 2019). Although alcohol has prominence in military culture (Teachman et al., 2015) and may therefore be tied to military identity, this relationship may vary based on a number of factors (e.g., service branch, deployment/combat history, and gender). Limited evidence suggests that identity-related challenges may be different for active duty members, compared to reservists (Orazem et al., 2016), which could lead to differences in outcomes. While active duty members often discussed feeling they did not belong in civilian society, National Guard/Reserve members discussed difficulty in returning to formerly established civilian identities (Orazem et al., 2016). This variation may relate to challenges in different ways, through varying degrees of social isolation. Future studies should explore in greater detail the conditions under which there are potential relationships between military identity and problematic alcohol use.

Our study found that stronger military identity was related to greater odds of past-three-months NMUPD. To our knowledge, this has not been assessed previously, but is important to examine in future studies. The prevalence of misuse of prescription medications has increased in military samples, in particular the use of pain medications, and data indicate that mental health conditions, such as PTSD, relate to increased likelihood of misuse (Bray et al., 2012). This type of use may indicate self-medication for problems with mental and/or physical health (Bray et al., 2012) and an avoidance of help-seeking. It is possible that individuals with stronger military identity, with its associated emphasis on traditionally masculine traits, may see admitting difficulties as being in conflict with an identity which emphasizes strength and self-reliance (Lorber & Garcia, 2010). Significant work has been done in the United States military to address aspects of military culture and stigma that inhibit individuals from seeking help for mental or physical health-related problems (Acosta et al., 2014; Dickstein et al., 2010). However, there has been less attention to individuals’ own identity conceptions, and how variations in the importance individuals attach to their military identity may play a role in help-seeking. Our results suggest that military identity may be an important factor to consider in understanding the relationship between mental health, pain, and NMUPD. Future research is needed to explore in greater detail relationships between military identity and the non-medical use of different classes of prescription drugs (e.g., sedatives vs. stimulants vs. pain medications) motivations for this use, and how these are impacted by military service history and life-course experiences.

This work is subject to limitations. These analyses are cross-sectional, and therefore, assertions about causality or ordering cannot be made. While military identity may not cause problems with mental health or substance use, stronger military identity in the presence of these problems, may contribute to greater symptoms, symptom persistence, or inhibited treatment-seeking. Future research should examine this in greater detail. Further, data were collected on a population of Reserve and National Guard soldiers in New York State; the findings may not apply to other military populations or geographic regions, though our sample demographics are similar to those of reserve soldiers nationally (Department of Defense (DoD) 2021).

Overall, our findings contribute to a growing body of research that demonstrates the importance of considering the role of military identity in understanding service members’ health-related outcomes. We extend this work through empirical examination of quantitative data on a large sample of Reserve and National Guard soldiers, which show that stronger military identity is associated with greater symptoms of anger, generalized anxiety, depression, and PTSD, and with greater risk of NMUPD. Future research is needed to examine these relationships over time, and to identify possible mechanisms by which interventions for mental health and substance use can integrate and address the possible role of identity-related challenges.

Funding Statement

This research was supported by the National Institute on Drug Abuse award number [R01DA034072] to Gregory G. Homish and by the National Center for Advancing Translational Sciences of the National Institutes of Health under award number [UL1TR001412] to the University at Buffalo. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

Limited data that support the findings of this study are available on reasonable request from the corresponding author [BV]. The data are not publicly available due to their containing information that could compromise the privacy of research participants.