Item response theory analysis of lifetime cannabis-use disorder symptom severity in an American Indian community sample

Social zeitgeber and sleep loss as risk factors for suicide in American Indian adolescents

American Indians / Alaska Natives (AI/AN) bear a high burden of suicide, the reasons for which are not completely understood, and rates can vary by tribal group and location. This article aims to identify circumstances reported by a community group of American Indian adolescent participants to be associated with their depression and/or suicide. American Indian adolescents (n  =  360) were recruited from contiguous reservations and were assessed with a semi-structured diagnostic interview. Twenty percent of the adolescents reported suicidal thoughts (ideation, plans), an additional 8% reported a history of suicide attempts, and three deaths due to suicide were reported. Suicidal behaviors and major depressive disorder (MDD) co-occurred and were more common among female adolescents. The distressing events that adolescents most often reported were: death in the family, family disruption, peer relationship problems, and school problems. All of these events were significantly associated with suicidal behaviors, however those with suicidal acts were more likely to report death in the family. Those with MDD but no suicidal behaviors were more likely to report disruptions in the family. Disruptions in falling asleep were also associated with suicidal behaviors and having experienced a death in the family. Disruptions in important relationships, particularly through death or divorce, may be interpreted as a loss or disruption in "social zeitgebers" that may in turn disturb biological rhythms, such as sleep, thus potentially increase the risk for MDD and/or suicide. Prevention programs aimed at ameliorating the impact of disruptions in important relationships may potentially reduce suicidal behaviors in AI/AN adolescents.

Comorbidity of anxiety/affective, conduct/antisocial, attention deficit, and alcohol use disorders with suicidal behaviors in an American Indian community sample of adults and adolescents

AIMS

To study the associations of anxiety/affective disorders, conduct/antisocial disorders (ASPD/CD), attention deficit disorders (ADHD), and alcohol use disorders (AUD) with suicidal behaviors in an American Indian (AI) community sample of adolescents and adults.

METHODS

Participants were AI (360 adolescents, 925 adults) recruited from reservations who were assessed with the Semi-Structured Assessment for the Genetics of Alcoholism (SSAGA).

RESULTS

Among AI adults (mean age = 33 years), 17% percent reported lifetime experiences of suicidal thoughts (ideation and/or plans) and 14% reported suicidal acts (including either a suicide attempt history or verified death by suicide; n = 19 deaths). Among AI adolescents (mean age = 15 years), 20% experienced suicidal thoughts and 9% experienced suicidal acts (including 3 deaths). In logistic regression analyses, suicidal thoughts were significantly associated with lifetime diagnoses of affective disorder, CD and ADHD in adolescents, and with anxiety disorder, affective disorder, and ASPD/CD in adults. Suicidal acts were associated with affective disorder, ADHD, and alcohol drinking in adolescents and with anxiety disorder, ASPD/CD and AUD in adults. The number of comorbid disorders greatly increased the risk of both suicidal thoughts and acts among both adolescents and adults.

CONCLUSIONS

In addition to affective disorders, both ADHD and CD in adolescents, and ASPD in adults, demonstrated an association with suicidal thoughts. Alcohol use by adolescents and AUD among adults also were associated with suicidal attempts in this AI sample. These findings suggest need for additional research and potential integration of alcohol in screening and intervention programs focused on the prevention of suicide among AI.

Pleiotropic loci for cannabis use disorder severity in multi-ancestry high-risk populations

Cannabis use disorder (CUD) is common and has in part a genetic basis. The risk factors underlying its development likely involve multiple genes that are polygenetic and interact with each other and the environment to ultimately lead to the disorder. Co-morbidity and genetic correlations have been identified between CUD and other disorders and traits in select populations primarily of European descent. If two or more traits, such as CUD and another disorder, are affected by the same genetic locus, they are said to be pleiotropic. The present study aimed to identify specific pleiotropic loci for the severity level of CUD in three high-risk population cohorts: American Indians (AI), Mexican Americans (MA), and European Americans (EA). Using a previously developed computational method based on a machine learning technique, we leveraged the entire GWAS catalog and identified 114, 119, and 165 potentially pleiotropic variants for CUD severity in AI, MA, and EA respectively. Ten pleiotropic loci were shared between the cohorts although the exact variants from each cohort differed. While majority of the pleiotropic genes were distinct in each cohort, they converged on numerous enriched biological pathways. The gene ontology terms associated with the pleiotropic genes were predominately related to synaptic functions and neurodevelopment. Notable pathways included Wnt/β-catenin signaling, lipoprotein assembly, response to UV radiation, and components of the complement system. The pleiotropic genes were the most significantly differentially expressed in frontal cortex and coronary artery, up-regulated in adipose tissue, and down-regulated in testis, prostate, and ovary. They were significantly up-regulated in most brain tissues but were down-regulated in the cerebellum and hypothalamus. Our study is the first to attempt a large-scale pleiotropy detection scan for CUD severity. Our findings suggest that the different population cohorts may have distinct genetic factors for CUD, however they share pleiotropic genes from underlying pathways related to Alzheimer's disease, neuroplasticity, immune response, and reproductive endocrine systems.

Trauma, historical trauma, PTSD and suicide in an American Indian community sample

AIMS

To study the associations between perceived historical trauma, current traumatic events, diagnoses of post-traumatic stress disorder (PTSD), and suicidal behaviors in an American Indian community sample.

METHODS

Participants were American Indians recruited from reservations who were assessed with the Semi-Structured Assessment for the Genetics of Alcoholism (SSAGA), as well as the Historical Loss Scale, Historical Loss Associated Symptoms Scale, and Stressful Life Events Scale.

RESULTS

In data from 447 American Indian adults (mean age = 33 years), twenty percent reported lifetime experiences of suicidal thoughts (ideation and/or plans) and 14% reported suicidal acts, (including either a suicide attempt history or verified death by suicide (n = 4)). Diagnosis of PTSD and experience of assaultive trauma were each significantly associated with suicidal thoughts and acts, although assaultive trauma did not remain significant in models adjusting for gender and PTSD. High endorsement of symptoms associated with historical trauma was significantly associated with suicidal acts, and this remained significant when adjusting for gender and PTSD.

CONCLUSIONS

PTSD and historical trauma have an association with suicide and suicidal attempts in this American Indian community. Although further research is needed to evaluate the causal nature of these relations, these findings suggest treatment and prevention programs for American Indian suicide may benefit from addressing issues related to feelings of historical losses, PTSD, and their associated symptomatology.

The latent trait of ICD-11 nicotine dependence criteria: Dimensional and categorical phenotypes

We aimed to identify phenotypes of DSM-ICD nicotine dependence among a representative sample of lifetime weekly smokers in the largest metropolitan area in South America. Data came from 1,387 lifetime weekly smokers in the São Paulo Megacity Mental Health Survey. We used exploratory factor analysis (EFA) and latent class analysis (LCA) on ICD-11 nicotine dependence proposed criteria to explore dimensionality and phenotypes profiles, followed by logistic regression models to examine the association between latent classes and socio-demographic, psychiatric and chronic medical conditions. Analyses were performed using Mplus taking into account the complex survey design features. An unidimensional model had the best EFA fit with high loadings on all criteria. Response patterns detected by LCA indicated class differences based on severity continuum: a "non-symptomatic class" (32.0%), a "low-moderate symptomatic class" (34.9%)-with high probability of the criterion "use in larger amounts", and a "high-moderate symptomatic class" (33.1%). We found an association between high-income and the intermediate class that differs from findings in high-income countries, and high likelihood of psychiatric comorbidity among the most symptomatic smokers. The best dimensional model that pulled together nicotine dependence criteria supported a single factor, in concordance with the changes proposed for ICD-11.

Clinical characteristics of alcohol combined with other substance use disorders in an American Indian community sample

BACKGROUND

Alcohol and other substance use disorders (SUD) pose major problems of morbidity and mortality in some American Indian communities, but little is known about the clinical characteristics, risk factors, and consequences of combined alcohol and other substance use disorders (multi-substance use disorder, MSUD) in those communities.

METHODS

Using the Semi-Structured Assessment for the Genetics of Alcoholism (SSAGA), in a community sample of 876 American Indians, the clinical characteristics of lifetime DSM-5 moderate or severe alcohol use disorder alone (AUD alone) (n=146) and MSUD (defined as alcohol and ≥1 other SUD) (n=284) were evaluated and compared to 347 participants with no lifetime SUD (no SUD).

RESULTS

The majority (57%) of participants with a SUD had multi-substance use disorder and 94% of those were with AUD. Stimulants (cocaine and/or amphetamine) and/or cannabis were the most common other SUDs. Participants with AUD alone were more likely to be male and have an earlier age of first alcohol intoxication than those with no SUD. Those with MSUD were more likely to have dropped out of high school, have antisocial personality disorder (ASPD) or conduct disorder (CD), have earlier ages of first alcohol intoxication and first use of cannabis and stimulants, an earlier age of onset of AUD, and more of several AUD symptoms than those with AUD alone, but the same temporal course and time to remission of AUD.

CONCLUSIONS

MSUD is prevalent in this sample, is associated with multiple comorbidities and denotes a more severe alcohol syndrome than AUD alone.

Low voltage alpha EEG phenotype is associated with reduced amplitudes of alpha event-related oscillations, increased cortical phase synchrony, and a low level of response to alcohol

Low voltage EEG (LVEEG) is a heritable phenotype that differs depending on ancestral heritage, yet its impact on brain networks and cognition remain relatively unexplored. In this study we assessed energy and task related phase locking of event-related oscillation (EROs), behavioral responses, measures of IQ and personality, and expected responses to alcohol in a large sample of individuals with LVEEG compared to those with higher voltage variants. Participants (n=762) were recruited from a Native American community and completed a diagnostic interview, the Quick Test, the Subjective High Assessment Scale Expectation Version (SHAS-E) and the Maudsley Personality Inventory. Clinical and spectral analyzed EEGs were collected for determination of the presence of a LVEEG variant. EROs were generated using a facial expression recognition task. Participants with LVEEG (n=451) were significantly more likely to be older, married and have higher degrees of Native American heritage but did not differ in gender, income or education. Individuals with LVEEG were also found to have decreased energy in their alpha EROs, increased phase locking between stimulus trials, and increased phase-locking between cortical brain areas. No significant differences in the cognitive tests, personality variables or alcohol dependence or anxiety diagnoses were found, however, individuals with LVEEG did report a larger number of drinks ever consumed in a 24-h period and a less intense expected response to alcohol. These data suggest that alpha power in the resting EEG is highly associated with energy and cortical connectivity measures generated by event-related stimuli, as well as potentially increased risk for alcohol use.

Item response theory analyses of DSM-IV and DSM-5 stimulant use disorder criteria in an American Indian community sample

BACKGROUND

Native Americans experience some of the highest rates of DSM-IV stimulant dependence (SD) of all U.S. ethnic groups. This report compares DSM-IV and DSM-5 stimulant use disorder (SUD) diagnostic criteria in an American Indian community sample.

METHODS

Demographic information, stimulant (methamphetamine or cocaine) use, and lifetime DSM-IV and DSM-5 diagnoses were assessed in 858 adult American Indians. Item Response Theory (IRT) analyses were used to assess SUD criteria in both DSM-IV and DSM-5 criteria sets along an underlying latent trait severity continuum and the effect of demographic variables on differential item functioning (DIF) in those criteria.

RESULTS

The overall rate of DSM-IV SD was 33%, of DSM-IV SUD was 38%, and of DSM-5 SUD was 36% with no gender differences. All SUD symptoms in both the DSM-IV and DSM-5 datasets functioned on the moderate portion of the underlying severity continuum. "Craving" discriminated better than any other criterion at its level of severity in indicating the presence or absence of SUD. There was little DIF in groups defined by gender or any other demographic variable in either the DSM-IV or DSM-5 datasets.

CONCLUSIONS

These findings indicate that in this American Indian sample, diagnostic criteria for DSM-IV and DSM-5 SUD function similarly in terms of severity and DIF and that the abolition of the DSM-IV distinction between stimulant abuse and dependence in DSM-5 is warranted.

Measuring historical trauma in an American Indian community sample: contributions of substance dependence, affective disorder, conduct disorder and PTSD

BACKGROUND

The American Indian experience of historical trauma is thought of as both a source of intergenerational trauma responses as well as a potential causative factor for long-term distress and substance abuse among communities. The aims of the present study were to evaluate the extent to which the frequency of thoughts of historical loss and associated symptoms are influenced by: current traumatic events, post traumatic stress disorder (PTSD), cultural identification, percent Native American Heritage, substance dependence, affective/anxiety disorders, and conduct disorder/antisocial personality disorder (ASPD).

METHODS

Participants were American Indians recruited from reservations that were assessed with the Semi-Structured Assessment for the Genetics of Alcoholism (SSAGA), The Historical Loss Scale and The Historical Loss Associated Symptoms Scale (to quantify frequency of thoughts and symptoms of historical loss) the Stressful-Life-Events Scale (to assess experiences of trauma) and the Orthogonal Cultural Identification Scale (OCIS).

RESULTS

Three hundred and six (306) American Indian adults participated in the study. Over half of them indicated that they thought about historical losses at least occasionally, and that it caused them distress. Logistic regression revealed that significant increases in how often a person thought about historical losses were associated with: not being married, high degrees of Native Heritage, and high cultural identification. Additionally, anxiety/affective disorders and substance dependence were correlated with historical loss associated symptoms.

CONCLUSIONS

In this American Indian community, thoughts about historical losses and their associated symptomatology are common and the presence of these thoughts are associated with Native American Heritage, cultural identification, and substance dependence.

Contributions of ethnicity to differential item functioning of cannabis abuse and dependence symptoms

OBJECTIVE

Cannabis is the most widely used illicit drug in the United States, and as a result, it is associated with significant public health costs. The present study sought to investigate whether item response theory (IRT) methods could be used to identify meaningful differences in how cannabis abuse and dependence symptoms (determined by criteria from the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition) function as indices of the severity of misuse across two ethnic groups: Native Americans and European Americans.

METHOD

Participants were drawn from two previously collected samples, a population of Native Americans living on contiguous reservations (n = 406) and the University of California at San Francisco Family Alcoholism Study (n = 728). Cannabis use disorder symptoms were assessed using the Semi-Structured Assessment for the Genetics of Alcoholism.

RESULTS

Exploratory factor analysis demonstrated that the cannabis abuse and dependence symptoms indexed a single latent trait measuring severity of cannabis use. IRT and multiple indicators multiple causes (MIMIC) analyses suggested meaningful differences in the functioning of these symptoms across ethnic groups. Withdrawal represented a more prevalent and less severe symptom among Native Americans relative to European Americans, whereas each of the cannabis abuse symptoms and a symptom assessing psychological and health problems resulting from cannabis use were less prevalent but more severe in Native Americans.

CONCLUSIONS

The findings suggest differences in how cannabis use disorders manifest in these populations and thus have implications for the assessment of these disorders as well as theories attempting to explain the increased rates of substance use diagnoses more generally among Native Americans living on reservations.

Lifetime history of traumatic events in an American Indian community sample: heritability and relation to substance dependence, affective disorder, conduct disorder and PTSD

American Indians appear to experience a higher rate of traumatic events than what has been reported in general population surveys. American Indians also suffer higher alcohol related death rates than any other ethnic group in the U.S. population. Therefore efforts to delineate factors which may uniquely contribute to increased likelihood of trauma, post traumatic stress disorder (PTSD), and substance use disorders (SUD) over the lifetime in American Indians are important because of the high burden of morbidity and mortality that they pose to American Indian communities. Participants were American Indians recruited from reservations that were assessed with the Semi-Structured Assessment for the Genetics of Alcoholism (SSAGA), family history assessment and the stressful-life-events scale. Of the 309 participants, equivalent numbers of men and women (94%) reported experiencing traumas; however, a larger proportion of women received a PTSD diagnosis (38%) than men (29%). Having experienced multiple trauma and sexual abuse were most highly associated with PTSD. Having experienced assaultive trauma and having PTSD symptoms were both found to be moderately heritable (30-50%). Logistic regression revealed that having an anxiety and/or affective disorder and having a substance dependent diagnosis, but not having antisocial personality disorder/conduct disorder, were significantly correlated with having a diagnosis of PTSD. These studies suggest that trauma is highly prevalent in this American Indian community, it is heritable, is associated with PTSD, affective/anxiety disorders and substance dependence. Additionally, trauma, PTSD and substance dependence appear to all co-emerge in early adulthood in this high-risk population.

Item analysis and differential item functioning of a brief conduct problem screen

Research has shown that boys display higher levels of childhood conduct problems than girls, and Black children display higher levels than White children, but few studies have tested for scalar equivalence of conduct problems across gender and race. The authors conducted a 2-parameter item response theory (IRT) model to examine item characteristics of the Authority Acceptance scale from the Teacher Observation of Classroom Adaptation-Revised (AA-TOCA-R; L. Larsson-Werthamer, S. G. Kellam, & L. Wheeler, 1991) in 8,820 kindergarten children and estimated the degree of differential item functioning (DIF) by gender and race/urban status. The mean level of latent conduct problems was best represented by behaviors such as being stubborn, breaking rules, and being disobedient, whereas breaking things and taking others' property best represented the construct at one standard deviation above the mean. DIF by gender was detected, such that at equivalent levels of latent conduct problems, males received more endorsements of overt behaviors from teachers, whereas females received more endorsements of nonphysical behaviors. Moreover, overt behaviors were better discriminators of latent conduct problems for males, and nonphysical behaviors were better discriminators of latent conduct problems for females. Differences across race/urban status were not found to be conceptually meaningful. The authors' analyses also suggest that the item scaling of the AA-TOCA-R may be best represented by 5e categories instead of 6. These findings provide support for the use of IRT modeling to examine item characteristics of conduct problem scales and DIF to test for scalar equivalence across diverse subpopulations.

Linkage analyses of stimulant dependence, craving, and heavy use in American Indians

Amphetamine-type substances are the second most widely used illicit drugs in the United States. There is evidence to suggest that stimulant use (cocaine and methamphetamine) has a heritable component, yet the areas of the genome underlying these use disorders are yet to be identified. This study's aims were to map loci linked to stimulant dependence, heavy use, and craving in an American Indian community at high risk for substance dependence. DSM diagnosis of stimulant dependence, as well as indices of stimulant "craving," and "heavy use," were obtained using the Semi-Structured Assessment for the Genetics of Alcoholism (SSAGA). Genotypes were determined for a panel of 791 microsatellite polymorphisms in 381 members of multiplex families using SOLAR. Stimulant dependence, stimulant "craving," and "heavy stimulant use," were all found to be heritable. Analyses of multipoint variance component LOD scores, failed to yield evidence of linkage for stimulant dependence. For the stimulant "craving" phenotype, linkage analysis revealed a locus that had a LOD score of 3.02 on chromosome 15q25.3-26.1 near the nicotinic receptor gene cluster. A LOD score of 2.05 was found at this same site for "heavy stimulant use." Additional loci with LOD scores above 2.00 were found for stimulant "craving" on chromosomes 12p13.33-13.32 and 18q22.3. These results corroborate the importance of "craving" as an important phenotype that is associated with regions on chromosome 12, 15, and 18, that have been highlighted in prior segregation studies in this and other populations for substance dependence-related phenotypes.

Opioid dependence latent structure: two classes with differing severity?

AIMS

To examine the structure of illicit opioid abuse and dependence within an opioid dependent sample and its relationship to other clinical variables.

DESIGN, SETTING AND PARTICIPANTS

A cross-sectional study of 1511 opioid dependent individuals recruited through opioid pharmacotherapy clinics in the Sydney area, Australia.

MEASUREMENTS

A face-to-face structured interview covering substance use and dependence, psychiatric history, child maltreatment, family background, adult violence and criminal history. Dimensional, latent class and factor mixture models were fit to the opioid abuse and dependence data. Classes were then compared on a range of demographic and clinical covariates.

FINDINGS

A two-class, one-factor model provided the best fit of all the models tested. The two classes differed with respect to endorsement probabilities on a range of abuse and dependence criteria, and also with respect to the odds of other drug dependence diagnoses, antisocial personality disorder and non-fatal opioid overdose. Within-class severity was associated with similar variables: other drug dependence, borderline personality disorder and opioid overdose.

CONCLUSION

In an in-treatment, opioid-dependent sample, there appears to be two classes of individuals exhibiting distinct patterns of abuse and dependence criteria endorsement and to differ on externalizing but not internalizing disorders. This study provides preliminary evidence that the proposed DSM-V opioid use disorder distinction between moderate and severely dependent people is valid. Class one participants were not only more severely dependent, but had greater odds for opioid overdoses, other drug dependence and antisocial personality disorder.

Genome-wide scan for self-rating of the effects of alcohol in American Indians

OBJECTIVE

This study's aims were to map loci linked to self-rating of the effects of alcohol and to determine if there was overlap with loci mapped earlier for other substance dependence phenotypes in an American Indian community at high risk for substance dependence.

METHODS

Each participant gave a blood sample and completed a structured diagnostic interview using the Semi Structured Assessment for the Genetics of Alcoholism. Retrospective report of responses to alcohol during the FIRST FIVE TIMES they had ever drank alcohol was estimated from the Self-Rating of the Effects of Alcohol (SRE) questionnaire for each participant. Genotypes were determined for a panel of 791 micro-satellite polymorphisms in 381 members of multiplex families using SOLAR.

RESULTS

Analyses of multipoint variance component Log of Odds (LOD) scores, for the FIRST FIVE TIMES phenotype, revealed two loci that had a LOD score greater than 3.0 on chromosomes 6 and 9. In addition, three locations were identified with LOD scores above 2.0 on chromosomes 10, 12, 17.

CONCLUSION

These results corroborate the importance of regions on chromosome 6 and 9 highlighted in earlier segregation studies in this and other populations for substance dependence-related phenotypes, as well as an area on chromosome 10 earlier identified for the FIRST FIVE TIMES phenotype in the collaborative study on the genetics of alcoholism. These studies additionally lend further support the construct that the SRE may represent an important endophenotype associated with alcohol and other substance dependence.

EEG alpha phenotypes: linkage analyses and relation to alcohol dependence in an American Indian community study

BACKGROUND

Evidence for a high degree of heritability of EEG alpha phenotypes has been demonstrated in twin and family studies in a number of populations. However, information on linkage of this phenotype to specific chromosome locations is still limited. This study's aims were to map loci linked to EEG alpha phenotypes and to determine if there was overlap with loci previously mapped for alcohol dependence in an American Indian community at high risk for substance dependence.

METHODS

Each participant gave a blood sample and completed a structured diagnostic interview using the Semi Structured Assessment for the Genetics of Alcoholism. Bipolar EEGs were collected and spectral power determined in the alpha (7.5-12.0 Hz) frequency band for two composite scalp locations previously identified by principal components analyses (bilateral fronto-central and bilateral centro-parietal-occipital). Genotypes were determined for a panel of 791 micro-satellite polymorphisms in 410 members of multiplex families using SOLAR.

RESULTS

Sixty percent of this study population had a lifetime diagnosis of alcohol dependence. Analyses of multipoint variance component LOD scores, for the EEG alpha power phenotype, revealed two loci that had a LOD score of 3.0 or above for the fronto-central scalp region on chromosomes 1 and 6. Additionally, 4 locations were identified with LOD scores above 2.0 on chromosomes 4, 11, 14, 16 for the fronto-central location and one on chromosome 2 for the centro-parietal-occipital location.

CONCLUSION

These results corroborate the importance of regions on chromosome 4 and 6 highlighted in prior segregation studies in this and other populations for alcohol dependence-related phenotypes, as well as other areas that overlap with other substance dependence phenotypes identified in previous linkage studies in other populations. These studies additionally support the construct that EEG alpha recorded from fronto-central scalp areas may represent an important endophenotype associated with alcohol and other substance dependence.