Philip Lau

Co-Morbidity of Select Anxiety, Affective, and Psychotic Disorders with Cannabis Dependence in Southwest California Indians

Abstract Cannabis dependence is co-morbid with psychiatric disorders in general population surveys, but whether co-morbidity exists in American Indian populations is unknown. The aim of this study was to assess co-morbidity between cannabis dependence and psychiatric disorders in a community sample of Southwest California (SWC) Indians. Demographic information and DSM-III-R diagnoses, including differentiation of independent and cannabis-induced psychiatric disorders, were obtained using the Semi-Structured Assessment for the Genetics of Alcoholism (SSAGA) developed for the Collaborative Study on the Genetics of Alcoholism (COGA) from 513 SWC Indian adults residing on contiguous reservations. Although SWC Indians in this sample had high rates of cannabis dependence (43% in men and 24% in women), cannabis-induced psychiatric disorders each occurred in 1% or less of the sample. No significant co-morbidity with independent psychiatric disorders was found. In SWC Indians, cannabis dependence may be less etiologically related to psychiatric disorders than in the general population.

Heritability of illicit drug use and transition to dependence in Southwest California Indians

Objective Native Americans have high rates of drug use and dependence yet little is known concerning its etiology or clinical course. These analyses were conducted to describe the heritability of the use of a variety of illicit drugs, as well as the conditional probability of transitioning from use to dependence for each drug class in a community sample of Native American men and women. Methods The sample included 460 participants (190 men and 270 women), recruited through community effort, from eight contiguous Indian reservations in Southern California. Participants were assessed using the Semi-Structured Assessment for the Genetics of Alcoholism. The Semi-Structured Assessment for the Genetics of Alcoholism interview retrospectively asks about the initial use and drug dependence of the following illicit drug classes: marijuana, cocaine, stimulants, sedatives, opiates, hallucinogens, and solvents. Heritability of initial use was determined using SOLAR (http://www.sfbr.org/solar/). Results Ninety-one percent of this select Indian population had tried at least one of the illicit drug classes. The most commonly tried substance was marijuana (88%), followed by stimulants (60%), cocaine (44%), hallucinogens (34%), and solvents (20%). The heritability of initiation of drug use ranged from 0.14 for cocaine to 0.59 for marijuana. The conditional probability of transition from initiation to drug dependence ranged from 0.66 for stimulants to 0.06 for hallucinogens. Conclusions These findings suggest that heritability of the initiation of substance use, in Southwest California Indians, may be similar to other population samples. In this population, however, high rates of dependence on marijuana, opiates, and stimulants are seen once initiation of the use of the substance has occurred.

Electrophysiological Responses to Affective Stimuli in American Indians Experiencing Trauma With and Without PTSD

Abstract:  American Indians are at high risk for exposure to violence and other traumatic events, yet few studies have investigated posttraumatic stress disorder (PTSD) or its neurobiological consequences in Indian communities. In the present study, a sample of American Indians (n= 146) were given a structured diagnostic interview that additionally indexed traumatic life events and symptoms emerging following those events. Electroencephalogram (EEG) spectra and visual event‐related potentials (ERPs) to happy, sad, and neutral faces were also recorded from each participant. Ninety‐nine percent of the sample had experienced at least one category of trauma with the mean number being 5, 27% had experienced at least 8 categories, and 13% met DSM‐IV criteria for PTSD. The PTSD group did not differ on any demographic or diagnostic variables from the larger sample. An electrophysiological signature for PTSD was found that included increases in high‐frequency gamma activity (20–40 Hz, F= 8.7, P < 0.004) in frontal leads, higher N1 amplitudes to sad stimuli in frontotemporal leads (F= 12.4, P < 0.001, F= 5.0, P < 0.03) , and longer latency P3 components to happy stimuli in midline, central, and right frontal leads(F= 4.7, P < 0.03; F= 4.1, P < 0.04; F= 4.0, P < 0.05). These findings were observed in participants with PTSD, but not in a group with equivalently high trauma counts. These findings suggest that PTSD is associated with EEG hyperarousal, higher attentional levels to sad stimuli, and slower processing of happy stimuli. They also partially confirm ERP data reported in combat victims with PTSD suggesting that PTSD may induce neurobiological consequences that transcend type of eliciting trauma as well as ethnic and cultural factors.

Age at regular drinking, clinical course, and heritability of alcohol dependence in the San Francisco family study: a gender analysis.

We examined gender differences in age of onset, clinical course, and heritability of alcohol dependence in 2,524 adults participating in the University of California San Francisco (UCSF) family study of alcoholism. Men were significantly more likely than women to have initiated regular drinking during adolescence. Onset of regular drinking was not found to be heritable but was found to be significantly associated with a shorter time to onset of alcohol dependence. A high degree of similarity in the sequence of alcohol-related life events was found between men and women, however, men experienced alcohol dependence symptoms at a younger age and women had a more rapid clinical course. Women were found to have a higher heritability estimate for alcohol dependence (h(2)= .46) than men (h(2)= .32). These findings suggest that environmental factors influencing the initiation of regular drinking rather than genetic factors associated with dependence may in part underlie some of the gender differences seen in the prevalence of alcohol dependence in this population. (Am J Addict 2010;00:1-10).

Age of first marijuana use and the occurrence of marijuana use disorders in Southwest California Indians.

In several national surveys a younger age of substance usage has been associated with a higher likelihood of the development of dependence. Some studies have suggested that age at first use is primarily an environmentally driven variable, whereas others suggest that it may be partially mediated by a general vulnerability to exhibit problem behaviors. Although Native Americans, overall, have the highest prevalence of substance dependence of any US ethnic group, the relationship of age of first marijuana use on the development of dependence in Native American populations is relatively unknown. Demographic information and DSM-III-R diagnoses were obtained from 525 Southwest California Indian adults residing on contiguous reservations. Multinomial logistic regression was used to investigate the relationship between age of first use and marijuana use disorders. Early marijuana use was found to be strongly associated with abuse and dependence in this population, even in the presence of several other risk factors including externalizing diagnoses. These data suggest that effective environmental prevention efforts at reducing early marijuana use may be an important strategy to lower the prevalence of use disorders in this high risk population.

Factors Associated with Remission from Cannabis Dependence in Southwest California Indians

Abstract Cannabis is the most widely used illicit substance in the United States, and rates of cannabis use disorders in some Native American samples have been reported to be higher than in the general U.S. population. However, little is known about factors which are associated with remission from cannabis dependence in any ethnicity. Using the SSAGA, this study examined variables associated with complete remission (defined as no symptoms of dependence for 6 months or more) from DSM-III-R cannabis dependence in 159 Southwest California Indians living on contiguous reservations. Female gender, employment, having more cannabis-induced symptoms, and a shorter duration of dependence were all associated with an increased likelihood of remission. Attention to factors associated with remission from cannabis dependence may be important in designing more effective treatment and intervention programs in this high-risk population.

Factors Associated with Remission from Alcohol Dependence in an American Indian Community Group

OBJECTIVE This study identified factors associated with remission from DSM-III-R alcohol dependence in an American Indian community group. METHOD Participants were assessed by using the Semi-Structured Assessment for the Genetics of Alcoholism. RESULTS Five hundred eighty participants were assessed for alcohol use and alcohol use symptoms; 254 participants were found to have alcohol dependence. The rate of remission in this group was 59%. Thirty-four percent of remitters and 39% of nonremitters had received treatment for alcohol problems. Remission from alcohol dependence was associated with being female, older, and married; an earlier age of onset of alcohol dependence; and self-reported depression symptoms from drinking. Absence of remission was associated with continuing to drink despite knowing one had medical problems from drinking and self-reported anxiety symptoms from drinking. CONCLUSIONS Attention to factors associated with remission from alcohol dependence may be important in designing more effective treatment and prevention programs in this high-risk population.

Testing of an orthogonal measure of cultural identification with adult Mission Indians.

The Orthogonal Cultural Identification Scale (OCIS; Oetting & Beauvais, 1990-91) has been validated among Native American youth, but not adults. The present study sought to test the reliability (internal consistency) and validity (construct and factorial) of the OCIS among an adult Native American sample consisting of 389 Mission Indians (61% female). Participants were recruited from reservations using a venue sampling strategy. The OCIS was completed as part of a self-assessment packet of questionnaires. Internal consistency for OCIS subscale scores ranged from 0.76 to 0.91. Both concurrent and discriminant validity were demonstrated. Confirmatory factor analysis revealed 2 factors: (1) Anglo American Identification and (2) Native American Identification. These results indicate the OCIS is a reliable and valid instrument for use with adult Native Americans.

A co-morbidity of alcohol dependence with other psychiatric disorders in young adult Mexican Americans.

Abstract Background: Mexican Americans comprise one of the most rapidly growing populations in the U.S. However, information on the co-morbidity of alcohol dependence with other psychiatric disorders in Mexican Americans is sparse. Methods: Demographic information, DSM-III-R diagnoses, and information differentiating independent from substance-induced anxiety and affective disorders were obtained from 240 Mexican American young adults residing in select areas of San Diego. Results: A high prevalence of alcohol dependence was found in this population. There was significant co-morbidity between alcohol dependence and anxiety, affective, conduct/antisocial, and other substance dependence disorders. Eight percent of the anxiety disorders and 26% of the affective disorders were found to be substance-induced. Conclusion: High rates and substantial co-morbidity of alcohol dependence with psychiatric and other substance use disorders were found in this population. These data may be helpful in designing prevention and intervention programs for this high-risk population.

Stimulant dependence and stimulant-associated psychosis: clinical characteristics and age of onset in a Native American community sample

Objectives: Native Americans experience some of the highest rates of Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) stimulant dependence (SD) of all US ethnic groups. The present report examined the clinical characteristics and age of onset of stimulant use, SD, remission from SD, and stimulant-associated psychosis (SAP) in a Native American community sample. Methods: Demographic information, stimulant (methamphetamine or cocaine) use, and lifetime Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) psychiatric disorder diagnoses were assessed in 858 Native Americans. Logistic regression was used to assess the associations of demographic, stimulant use, and psychiatric disorder variables with SD, remission from SD, and SAP. Kaplan-Meier survival analyses were used to assess time from first use to the onset of SD. Results: The overall rate of SD was 33%, of remission from SD 73%, and of SAP 17%. Stimulant dependence was associated with older age, less current annual household income, fewer lifetime years of education, intravenous stimulant use, and earlier age of first stimulant use. Remission from SD was associated with older age, currently being married, and never having used stimulants intravenously. Attention-deficit/hyperactivity disorder (assessed as a lifetime disorder), increased number of years of daily stimulant use, and intravenous use were independently associated with SAP. Younger age at first use was significantly associated with shorter survival to the onset of SD. Conclusions: Stimulant dependence is prevalent in this population and is associated with less income and education and an earlier age at first use. Intravenous stimulant use adds additional risk for SD, nonremission, and psychosis.