Table 1.

Comparison studies of PTSD among American Indians and Alaska Natives

Author- Year	Time Frame	Sample Size & Population	Criteria & Methods	Inciting Events	Diagnostic measure	Comorbidities & Risk Factors	Major Findings
BeAIs 2002[1]	1990	Male AI/AN Vietnam veterans 305 from Northern Plains, 316 from Southwest	Statistical analysis	Combat experience	DSM-III-R	Risk factor: exposure to violence and atrocities	AI/AN Vietnam veterans were compared to Vietnam veterans from the general population. Lifetime PTSD diagnosis was highest in Northern Plains (57%) and second highest in Southwest (45%).
BeAIs 2005a[2]	1997 - 2000	1446 Southwest AIs 1638 Northern Plains AIs	Random sample from tribal rolls Statistical analysis		DSM-IV	Comorbidity: substance use disorders Risk factors: substance use disorders; at least one existing psychiatric disorder; more than high school education	PTSD was most prevalent among women in both tribes; Southwest women had higher risk for depressive and anxiety disorders and lower risk for substance disorders. Poverty, unemployment, and married/single status were not associated with psychiatric disorders.
BeAIs 2005b[3]	1997 - 1999	1446 Southwest AIs 1638 Northern Plains AIs	Random sample from tribal rolls Statistical analysis		DSM-III-R		Compared with U.S. general population in National Comorbidity Survey, lifetime MD episodes were lower in the Northern Plains. Men more likely than general population to seek help for substance abuse. Women less likely to talk to non-specialty providers about emotional problems. Use of traditional healers common in both groups, especially in the Southwest.
BeAIs 2012[4]	1997 - 2000	1967 AIs, including Southwest and Northern Plains	Random sample from tribal rolls Statistical analysis		DSM-IV	Risk factor: exposure to traumatic events	Gender differences apparent in reporting of type of trauma. Worst event listed by men: accidents (either experienced or witnessed) Worst event listed by women: spousal abuse, witnessed familial violence, and rape/molestation Both genders in these populations at greater risk for trauma exposure and subsequent PTSD than other American.
Buchwald 2005[5]	1997 - 2000	1446 Southwest AI/ANs 1638 Northern Plains AI/ANs	Random sample from tribal rolls Descriptive statistics, linear regression		DSM-IV	Comorbidity: bodily pain	Women twice as likely as men to have lifetime PTSD. Men and women with lifetime PTSD had more bodily pain than those without.
C’De Baca 2004[6]	1989 - 1992	758 male and 631 female alcohol- impaired offenders (AI/AN, Hispanic, NHW) referred to screening program in New Mexico	Referral to screening program Interviews, statistical analysis		DSM-III-R		AI/AN women had lower prevalence of alcohol dependence, nicotine dependence, and MD than NHW women. AI/AN men had lower prevalence of drug dependence, nicotine dependence, and antisocial personality disorder than NHW men. After adjusting for covariates, AI/ANs and Hispanics had lower prevalence of substance abuse and mental health problems than NHWs. Age-adjusted lifetime prevalence of PTSD for men was highest for AI/AN men (13.2%); for women, the rate was highest for NHWs (29.2%) and second highest for AI/ANs (26.6%).
Libby 2005[7]	1997 - 2000	1446 Southwest AI/ANs 1638 Northern Plains AI/ANs	Random sample from tribal rolls Descriptive statistics, bivariate logistic regression	CSA	DSM-IV	Risk factors: CSA, adult physical or sexual abuse, chronic illness, lifetime alcohol or drug disorder, parental depression, alcoholism, or violence.	Prevalence of childhood physical abuse was ~7% for both tribes Southwest tribe had higher prevalence of depressive and anxiety disorders, highest prevalence of PTSD. CSA was significant predictor of all disorders for males in both tribes, except for panic and GAD for Northern Plains. CSA was an independent predictor of PTSD for both tribes after controlling for covariates. Adult physical or sexual abuse, chronic illness, lifetime alcohol or drug disorder, parental problems with depression, and alcohol or violence were risk factors for depressive and anxiety disorders.
Manson 2005[8]	1997 - 2000	1446 Southwest AI/ANs 1638 Northern Plains AI/ANs	Random sample from tribal rolls Statistical analysis				Lifetime prevalence for exposure to ≥ 1 trauma were 62.4%-67.2% for men, 66.2%- 69.8% for women. Women in both areas were more likely to experience interpersonal violence. AI/ANs were more likely to witness traumatic events, experience trauma to loved ones, and experience physical attacks than general population
Palinkas 1993[9]	1990	599 men and women in Alaska (both AI/AN and White)	Community survey Statistical analysis	Oil spill	DSM-IV	Comorbidity: depressive symptoms	Post-spill prevalence for PTSD was 9.4% and GAD was 20.2% for all levels of exposure. Members of high-exposure group were 2.9 times as likely to have PTSD and 3.6 times as likely to have GAD. Women were more vulnerable to PTSD and GAD. AI/ANs were more vulnerable to depressive symptoms.
Palinkas 2004[10]	1990	188 AI/AN Alaska residents 371 White Alaska residents	Community survey Statistical analysis	Oil spill	DSM-IV	Risk factors: low family support, participation in clean- up activities, decline in subsistence activities	Both racial groups showed high levels of social disruption due to oil spill. Diagnosis of PTSD must take into consideration local interpretations of symptoms. Risk factors were associated with PTSD in AI/ANs but not in Whites
Ritsher 2002[11]	1996	14,662 U.S. adults	Attendees at 1240 sites for National Anxiety Disorders Screening Day Statistical analysis		DSM-IV	Risk factor: minority status	PTSD symptoms were more prevalent among Blacks, Hispanics, and AI/ANs.
Santos 2008[12]		269 injured inpatients at two U.S. Level 1 trauma centers, age 14 or older	Random sample Regression analysis		PCL	Risk factor: minority status	Regression analyses adjusted for covariates showed that ethnic minority patients (AI/AN, Black, Hispanic, Asian) had significant elevations in ≥ 1 posttraumatic symptom cluster.
Sprague 2010[13]	1997 - 2000	1208 Southwest AIs 1414 Northern Plains AIs	Random sample from tribal rolls Statistical analysis				Prevalence of lung disorders was 17% in Northern Plains and 13% in Southwest. In Northern Plains, men with lung disorders had higher prevalence of PTSD and MD than men without; women with lung disorders had higher prevalence of MD than women without. After controlling for covariates, only the association with MD persisted in both genders. In Southwest, neither PTSD nor MD was associated with lung disorders.
Stephens 2010[14]		623 acutely injured trauma center inpatients	Population- based sample Statistical analysis		PCL		AI/ANs and Blacks reported highest levels of posttraumatic stress and pre-injury cumulative trauma burden.
Walker 1994[15]	1991	3087 AI/AN veterans	Discharge abstracts from Department of Veterans Affairs hospitAIs Statistical analysis			Comorbidity: substance abuse, alcohol abuse Risk factors: substance use, younger age, unmarried status, male gender	Substance use disorders diagnosed in 46.3% of AI/AN veterans (23.4% all races). More than 97% of AI/AN substance abuse diagnoses were alcohol related. Higher prevalence of PD, depression, and PTSD in AI/ANs with substance use disorders than in AI/ANs without.
Westermeyer 2006[16]		1624 AI/AN and Hispanic veterans	Community-based survey Statistical analysis		DSM-III-R	Comorbidity: pathological gambling	Remission from pathological gambling associated with absence of Axis 1 disorder, especially current PTSD.