Independent and joint associations of cardiometabolic multimorbidity and depression on cognitive function: findings from multi-regional cohorts and generalisation from community to clinic.

Background: Cardiometabolic multimorbidity (CMM) and depression are often co-occurring in older adults and associated with neurodegenerative outcomes. The present study aimed to estimate the independent and joint associations of CMM and depression on cognitive function in multi-regional cohorts, and to validate the generalizability of the findings in additional settings, including clinical. Methods: Data harmonization was performed across 14 longitudinal cohort studies within the Cohort Studies of Memory in an International Consortium (COSMIC) group, spanning North America, South America, Europe, Africa, Asia, and Australia. Three external validation studies with distinct settings were employed for generalization. Participants were eligible for inclusion if they had data for CMM and were free of dementia at baseline. Baseline CMM was defined as: 1) CMM 5, ≥2 among hypertension, hyperlipidemia, diabetes, stroke, and heart disease and 2) CMM 3 (aligned with previous studies), ≥2 among diabetes, stroke, and heart disease. Baseline depression was primarily characterized by binary classification of depressive symptom measurements, employing the Geriatric Depression Scale and the Center for Epidemiological Studies-Depression scale. Global cognition was standardized as z-scores through harmonizing multiple cognitive measures. Longitudinal cognition was calculated as changes in global cognitive z-scores. A pooled individual participant data (IPD) analysis was utilized to estimate the independent and joint associations of CMM and depression on cognitive outcomes in COSMIC studies, both cross-sectionally and longitudinally. Repeated analyses were performed in three external validation studies. Findings: Of the 32,931 older adults in the 14 COSMIC cohorts, we included 30,382 participants with complete data on baseline CMM, depression, and cognitive assessments for cross-sectional analyses. Among them, 22,599 who had at least 1 follow-up cognitive assessment were included in the longitudinal analyses. The three external studies for validation had 1964 participants from 3 multi-ethnic Asian older adult cohorts in different settings (community-based, memory clinic, and post-stroke study). In COSMIC studies, each of CMM and depression was independently associated with cross-sectional and longitudinal cognitive function, without significant interactions between them (Ps > 0.05). Participants with both CMM and depression had lower cross-sectional cognitive performance (e.g. ß = -0.207, 95% CI = (-0.255, -0.159) for CMM5 (+)/depression (+)) and a faster rate of cognitive decline (e.g. ß = -0.040, 95% CI = (-0.047, -0.034) for CMM5 (+)/depression (+)), compared with those without either condition. These associations remained consistent after additional adjustment for APOE genotype and were robust in two-step random-effects IPD analyses. The findings regarding the joint association of CMM and depression on cognitive function were reproduced in the three external validation studies. Interpretation: Our findings highlighted the importance of investigating age-related co-morbidities in a multi-dimensional perspective. Targeting both cardiometabolic and psychological conditions to prevent cognitive decline could enhance effectiveness. Funding: Natural Science Foundation of China and National Institute on Aging/National Institutes of Health.

Multidisciplinary contributions towards an evolutive interpretation of bipolar disorders: could it be the pathological drift of a potentially adaptive condition?

This paper tries to summarize the results of studies from different areas of knowledge supporting the idea that temperamental traits, such as "reckless/hyper-exploratory" attitudes, commonly believed to be associated with psychopathology, surprisingly turn out as adaptive under specific stress conditions. In particular, this paper analyzes an ethologic line of research on primates suggesting models for a sociobiological interpretation of mood disorders in humans; a study that found high frequencies of a genetic variance associated with bipolar disorder in people without bipolar disorder but with hyperactivity/novelty-seeking traits; the outcomes of socio-anthropological-historical surveys on the evolution of mood disorders in Western countries in the last centuries; surveys on changing societies in Africa and African migrants in Sardinia; and studies that found higher frequencies of mania and subthreshold mania among Sardinian immigrants in Latin American megacities. Although it is not unequivocally accepted that the prevalence of mood disorders has increased, it would be logical to suppose that a nonadaptive condition should have disappeared over time; mood disorders, on the contrary, persist and their prevalence might have even increased. This new interpretation could lead to counter discrimination and stigma towards people suffering from the disorder and would be a central point in psychosocial treatments in addition to pharmacological therapy. Our aim is to hypothesize that bipolar disorder, strongly characterized by these traits, may be the result of the interaction between genetic characteristics, not necessarily pathological, and specific environmental conditions rather than a mere product of an aberrant genetic profile. If mood disorders were mere nonadaptive conditions, they would have disappeared over time; however, their prevalence paradoxically persists if not even increases over time. The hypothesis that bipolar disorder may result from the interaction between genetic characteristics, not necessarily pathological, and specific environmental factors seems more credible than considering bipolar disorder as a mere product of an aberrant genetic profile.

Correlates of Gait Speed Among Older Adults From 6 Countries: Findings From the COSMIC Collaboration.

BACKGROUND: Few studies have compared gait speed and its correlates among different ethnogeographic regions. The goals of this study were to describe usual and rapid gait speed, and identify their correlates across Australian, Asian, and African countries. METHODS: We used data from 6 population-based cohorts of adults aged 65+ from 6 countries and 3 continents (N = 6 472), with samples ranging from 231 to 1 913. All cohorts are members of the Cohort Studies of Memory in an International Consortium collaboration. We investigated whether clinical (body mass index [BMI], hypertension, stroke, apolipoprotein status), psychological (cognition, mood, general health), and behavioral factors (smoking, drinking, physical activity) correlated with usual (N = 4 cohorts) and rapid gait speed (N = 3 cohorts) similarly across cohorts. Regression models were controlled for age, sex, and education, and were sex-stratified. RESULTS: Age- and sex-standardized usual gait speed means ranged from 0.61 to 1.06 m/s and rapid gait speed means ranged from 1.16 to 1.64 m/s. Lower BMI and better cognitive function consistently correlated with faster gait speed in all cohorts. Less consistently, not having hypertension and greater physical activity engagement were associated with faster gait speed. Associations with mood, smoking, and drinking were largely nonsignificant. These patterns were not attenuated by demographics. There was limited evidence that the associations differed by sex, except physical activity, where the greater intensity was associated with usual gait among men but not women. CONCLUSIONS: This study is among the first to describe the usual and rapid gait speeds across older adults in Africa, Asia, and Australia.

Cannabis use and psychotic disorders in diverse settings in the Global South: findings from INTREPID II.

BACKGROUND: Cannabis use has been linked to psychotic disorders but this association has been primarily observed in the Global North. This study investigates patterns of cannabis use and associations with psychoses in three Global South (regions within Latin America, Asia, Africa and Oceania) settings. METHODS: Case-control study within the International Programme of Research on Psychotic Disorders (INTREPID) II conducted between May 2018 and September 2020. In each setting, we recruited over 200 individuals with an untreated psychosis and individually-matched controls (Kancheepuram India; Ibadan, Nigeria; northern Trinidad). Controls, with no past or current psychotic disorder, were individually-matched to cases by 5-year age group, sex and neighbourhood. Presence of psychotic disorder assessed using the Schedules for Clinical Assessment in Neuropsychiatry and cannabis exposure measured by the World Health Organisation Alcohol, Smoking and Substance Involvement Screening Test (ASSIST). RESULTS: Cases reported higher lifetime and frequent cannabis use than controls in each setting. In Trinidad, cannabis use was associated with increased odds of psychotic disorder: lifetime cannabis use (adj. OR 1.58, 95% CI 0.99-2.53); frequent cannabis use (adj. OR 1.99, 95% CI 1.10-3.60); cannabis dependency (as measured by high ASSIST score) (adj. OR 4.70, 95% CI 1.77-12.47), early age of first use (adj. OR 1.83, 95% CI 1.03-3.27). Cannabis use in the other two settings was too rare to examine associations. CONCLUSIONS: In line with previous studies, we found associations between cannabis use and the occurrence and age of onset of psychoses in Trinidad. These findings have implications for strategies for prevention of psychosis.

Late-life disability trajectories in Yoruba Nigerians and the Spanish population: a state space model in continuous time.

OBJECTIVES: We compared the trajectory of activities of daily living (ADL) in a nationally representative sample of older Nigerians with their Spanish peers and identified factors to explain country-specific growth models. METHODS: Data from two household multistage probability samples were used, comprising older adults from Spain (n = 2,011) and Nigeria (n = 1,704). All participants underwent assessment for ADL. Risk factors including sex, household income, urbanicity, years of education, depression, alcohol consumption and smoking were assessed using validated methods. State-space model in continuous time (SSM-CT) methods were used for trajectory comparison. RESULTS: Compared with Nigerians (µADL80=0.44, SE = 0.015, p < 0.001), Spanish older adults had higher disability scores (µADL80=1.23, SE = 0.021, p < 0.001). In SSM-CT models, the rate of increase in disability was faster in Nigerians (Nigeria: ß = 0.061, p<.01; Spain: ß = 0.028, p < 0.010). An increasing course of disability in the Spanish sample was predicted by female sex, lower education and depression diagnosis. CONCLUSION: The rate of increase in disability was faster in older Nigerians living in an economically disadvantaged context.

Association of Cohort and Individual Substance Use With Risk of Transitioning to Drug Use, Drug Use Disorder, and Remission From Disorder: Findings From the World Mental Health Surveys.

Importance: Limited empirical research has examined the extent to which cohort-level prevalence of substance use is associated with the onset of drug use and transitioning into greater involvement with drug use. Objective: To use cross-national data to examine time-space variation in cohort-level drug use to assess its associations with onset and transitions across stages of drug use, abuse, dependence, and remission. Design, Setting, and Participants: The World Health Organization World Mental Health Surveys carried out cross-sectional general population surveys in 25 countries using a consistent research protocol and assessment instrument. Adults from representative household samples were interviewed face-to-face in the community in relation to drug use disorders. The surveys were conducted between 2001 and 2015. Data analysis was performed from July 2017 to July 2018. Main Outcomes and Measures: Data on timing of onset of lifetime drug use, DSM-IV drug use disorders, and remission from these disorders was assessed using the Composite International Diagnostic Interview. Associations of cohort-level alcohol prevalence and drug use prevalence were examined as factors associated with these transitions. Results: Among the 90 027 respondents (48.1% [SE, 0.2%] men; mean [SE] age, 42.1 [0.1] years), 1 in 4 (24.8% [SE, 0.2%]) reported either illicit drug use or extramedical use of prescription drugs at some point in their lifetime, but with substantial time-space variation in this prevalence. Among users, 9.1% (SE, 0.2%) met lifetime criteria for abuse, and 5.0% (SE, 0.2%) met criteria for dependence. Individuals who used 2 or more drugs had an increased risk of both abuse (odds ratio, 5.17 [95% CI, 4.66-5.73]; P < .001) and dependence (odds ratio, 5.99 [95% CI, 5.02-7.16]; P < .001) and reduced probability of remission from abuse (odds ratio, 0.86 [95% CI, 0.76-0.98]; P = .02). Birth cohort prevalence of drug use was also significantly associated with both initiation and illicit drug use transitions; for example, after controlling for individuals' experience of substance use and demographics, for each additional 10% of an individual's cohort using alcohol, a person's odds of initiating drug use increased by 28% (odds ratio, 1.28 [95% CI, 1.26-1.31]). Each 10% increase in a cohort's use of drug increased individual risk by 12% (1.12 [95% CI, 1.11-1.14]). Conclusions and Relevance: Birth cohort substance use is associated with drug use involvement beyond the outcomes of individual histories of alcohol and other drug use. This has important implications for understanding pathways into and out of problematic drug use.

The associations between psychotic experiences and substance use and substance use disorders: findings from the World Health Organization World Mental Health surveys.

BACKGROUND AND AIMS: Prior research has found bidirectional associations between psychotic experiences (PEs) and selected substance use disorders. We aimed to extend this research by examining the bidirectional association between PEs and various types of substance use (SU) and substance use disorders (SUDs), and the influence of antecedent mental disorders on these associations. DESIGN, SETTING, PARTICIPANTS AND MEASUREMENTS: We used data from the World Health Organization World Mental Health surveys. A total of 30 902 adult respondents across 18 countries were assessed for (a) six types of life-time PEs, (b) a range of types of SU and DSM-IV SUDs and (c) mental disorders using the Composite International Diagnostic Interview. Discrete-time survival analyses based on retrospective age-at-onset reports examined the bidirectional associations between PEs and SU/SUDs controlling for antecedent mental disorders. FINDINGS: After adjusting for demographics, comorbid SU/SUDs and antecedent mental disorders, those with prior alcohol use disorders [odds ratio (OR) = 1.6, 95% confidence interval (CI) = 1.2-2.0], extra-medical prescription drug use (OR = 1.5, 95% CI = 1.1-1.9), alcohol use (OR = 1.4, 95% CI = 1.1-1.7) and tobacco use (OR = 1.3, 95% CI = 1.0-1.8) had increased odds of subsequent first onset of PEs. In contrast, those with temporally prior PEs had increased odds of subsequent onset of tobacco use (OR = 1.5, 95% CI = 1.2-1.9), alcohol use (OR = 1.3, 95% CI = 1.1-1.6) or cannabis use (OR = 1.3, 95% CI = 1.0-1.5) as well as of all substance use disorders (ORs ranged between 1.4 and 1.5). There was a dose response relationship between both count and frequency of PEs and increased subsequent odds of selected SU/SUDs. CONCLUSIONS: Associations between psychotic experiences (PEs) and substance use/substance use disorders (SU/SUDs) are often bidirectional, but not all types of SU/SUDs are associated with PEs. These findings suggest that it is important to be aware of the presence of PEs within those with SUDs or at risk of SUDs, given the plausibility that they may each impact upon the other.

Indicators for routine monitoring of effective mental healthcare coverage in low- and middle-income settings: a Delphi study.

High-quality information to measure the need for, and the uptake, cost, quality and impact of care is essential in the pursuit of scaling up mental health care in low- and middle-income countries (LMIC). The aim of this study was to identify indicators for the measurement of effective coverage of mental health treatment. We conducted a two-round Delphi study (n = 93 experts from primarily LMIC countries Ethiopia, India, Nepal, Nigeria, South Africa and Uganda), in order to generate and prioritize a set of indicators. First, 52 unique indicators were generated (based on a total of 876 responses from participants). Second, the selected indicators were then scored for significance, relevance and feasibility. Mean priority scores were calculated per indicator (score range, 1-5). All 52 indicators had a weighted mean score that ranged from 3.20 for the lowest ranked to 4.27 for the highest ranked. The 15 highest ranked indicators cover the different domains of measuring effective mental health treatment coverage. This set of indicators is highly stable between the different groups of experts, as well as between the different participating countries. This study provides data on how mental health service and financial coverage can be assessed in LMIC. This is an important element in the move to scale-up mental health care.

Genetic Influences on Plasma Homocysteine Levels in African Americans and Yoruba Nigerians.

Plasma homocysteine, a metabolite involved in key cellular methylation processes seems to be implicated in cognitive functions and cardiovascular health with its high levels representing a potential modifiable risk factor for Alzheimer's disease (AD) and other dementias. A better understanding of the genetic factors regulating homocysteine levels, particularly in non-white populations, may help in risk stratification analyses of existing clinical trials and may point to novel targets for homocysteine-lowering therapy. To identify genetic influences on plasma homocysteine levels in individuals with African ancestry, we performed a targeted gene and pathway-based analysis using a priori biological information and then to identify new association performed a genome-wide association study. All analyses used combined data from the African American and Yoruba cohorts from the Indianapolis-Ibadan Dementia Project. Targeted analyses demonstrated significant associations of homocysteine and variants within the CBS (Cystathionine beta-Synthase) gene. We identified a novel genome-wide significant association of the AD risk gene CD2AP (CD2-associated protein) with plasma homocysteine levels in both cohorts. Minor allele (T) carriers of identified CD2AP variant (rs6940729) exhibited decreased homocysteine level. Pathway enrichment analysis identified several interesting pathways including the GABA receptor activation pathway. This is noteworthy given the known antagonistic effect of homocysteine on GABA receptors. These findings identify several new targets warranting further investigation in relation to the role of homocysteine in neurodegeneration.

Prevalence and correlates of dizziness in the Ibadan Study of Ageing.

Dizziness is common among older people, but little is known about its prevalence and risk factors in the sub-Saharan population. We conducted a cross-sectional study to determine the prevalence of dizziness and its sociodemographic, lifestyle, and clinical correlates in 1,299 subjects--551 men (42.4%) and 748 women (57.6%), aged 65 years and older (mean: 77.3 ± 6.3)--who lived in the Yoruba-speaking areas of Nigeria. Among this group, 318 persons reported dizziness, which represents a prevalence of 24.5%. Univariate analysis of sociodemographic and lifestyle variables revealed that low economic status (p = 0.05) and smoking (p = 0.01) were significantly correlated with dizziness; however, on logistic regression analysis, only smoking (p = 0.01) was found to be significant. Neither sex (p = 0.07), age (p = 0.71), area of residence (p = 0.34), education level (p = 0.74), nor alcohol consumption (p = 0.44) had a significant correlation with dizziness. On multivariate modeling, significant clinical correlates in patients with dizziness included self-reports of a history of suppurative otitis media (p = 0.01), head injury (p = 0.03), and recurrent rhinosinusitis (p = 0.01); no significant correlation was seen between dizziness and hypertension, transient ischemic attack, and diabetes. Finally, balance testing conducted in a subset of 1,006 subjects revealed poor balance in 93 of 250 persons with dizziness (37.2%) and in 189 of 756 subjects without dizziness (25.0%) (p = 0.01). Logistic regression analysis of sex and age revealed that the probability of poor balance was 1.5 times greater among those persons with dizziness. We conclude that the high incidence of dizziness among community-dwelling elderly and its significant correlations with remediable medical conditions suggest the need for policy formulation for the care of the elderly in Nigeria.

Comorbidity of common mental disorders with cancer and their treatment gap: findings from the World Mental Health Surveys.

OBJECTIVE: This study aimed to study the comorbidity of common mental disorders (CMDs) and cancer, and the mental health treatment gap among community residents with active cancer, cancer survivors and cancer-free respondents in 13 high-income and 11 low-middle-income countries. METHODS: Data were derived from the World Mental Health Surveys (N = 66,387; n = 357 active cancer, n = 1373 cancer survivors, n = 64,657 cancer-free respondents). The World Health Organization/Composite International Diagnostic Interview was used in all surveys to estimate CMDs prevalence rates. Respondents were also asked about mental health service utilization in the preceding 12 months. Cancer status was ascertained by self-report of physician's diagnosis. RESULTS: Twelve-month prevalence rates of CMDs were higher among active cancer (18.4%, SE = 2.1) than cancer-free respondents (13.3%, SE = 0.2) adjusted for sociodemographic confounders and other lifetime chronic conditions (adjusted odds ratio (AOR) = 1.44, 95% CI 1.05-1.97). CMD rates among cancer survivors (14.6%, SE = 0.9) compared with cancer-free respondents did not differ significantly (AOR = 0.95, 95% CI 0.82-1.11). Similar patterns characterized high-income and low-middle-income countries. Of respondents with active cancer who had CMD in the preceding 12 months, 59% sought services for mental health problems (SE = 5.3). The pattern of service utilization among people with CMDs by cancer status (highest among persons with active cancer, lower among survivors and lowest among cancer-free respondents) was similar in high-income (64.0%, SE = 6.0; 41.2%, SE = 3.0; 35.6%, SE = 0.6) and low-middle-income countries (46.4%, SE = 11.0; 22.5%, SE = 9.1; 17.4%, SE = 0.7). CONCLUSIONS: Community respondents with active cancer have higher CMD rates and high treatment gap. Comprehensive cancer care should consider both factors.

Homocysteine levels and dementia risk in Yoruba and African Americans.

BACKGROUND: High levels of homocysteine have been associated with increased risk for dementia although results have been inconsistent. There are no reported studies from the developing world including Africa. METHODS: In this longitudinal study of two community-dwelling cohorts of elderly Yoruba and African Americans, levels of homocysteine, vitamin B12 and folate were measured from blood samples taken in 2001. These levels were compared in two groups, participants who developed incident dementia in the follow-up until 2009 (59 Yoruba and 101 African Americans) and participants who were diagnosed as cognitively normal or in the good performance category at their last follow-up (760 Yoruba and 811 African Americans). Homocysteine levels were divided into quartiles for each site. RESULTS: After adjusting for age, education, possession of ApoE, smoking, and time of enrollment the higher quartiles of homocysteine were associated with a non-significant increase in dementia risk in the Yoruba (homocysteine quartile 4 vs. 1 OR: 2.19, 95% CI 0.95-5.07, p = 0.066). For the African Americans, there was a similar but non-significant relationship between higher homocysteine levels and dementia risk. There were no significant relationships between levels of vitamin B12 and folate and incident dementia in either site although folate levels were lower and vitamin B12 levers were higher in the Yoruba than in the African Americans. CONCLUSIONS: Increased homocysteine levels were associated with a similar but non-significant increase in dementia risk for both Yoruba and African Americans despite significant differences in folate levels between the two sites.

Family burden related to mental and physical disorders in the world: results from the WHO World Mental Health (WMH) surveys

Objective: To assess prevalence and correlates of family caregiver burdens associated with mental and physical conditions worldwide. Methods: Cross-sectional community surveys asked 43,732 adults residing in 19 countries of the WHO World Mental Health (WMH) Surveys about chronic physical and mental health conditions of first-degree relatives and associated objective (time, financial) and subjective (distress, embarrassment) burdens. Magnitudes and associations of burden are examined by kinship status and family health problem; population-level estimates are provided. Results: Among the 18.9-40.3% of respondents in high, upper-middle, and low/lower-middle income countries with first-degree relatives having serious health problems, 39.0-39.6% reported burden. Among those, 22.9-31.1% devoted time, 10.6-18.8% had financial burden, 23.3-27.1% reported psychological distress, and 6.0-17.2% embarrassment. Mean caregiving hours/week was 12.9-16.5 (83.7-147.9 hours/week/100 people aged 18+). Mean financial burden was 15.1% of median family income in high, 32.2% in upper-middle, and 44.1% in low/lower-middle income countries. A higher burden was reported by women than men, and for care of parents, spouses, and children than siblings. Conclusions: The uncompensated labor of family caregivers is associated with substantial objective and subjective burden worldwide. Given the growing public health importance of the family caregiving system, it is vital to develop effective interventions that support family caregivers. .

An updated global picture of cigarette smoking persistence among adults.

BACKGROUND: Cross-national variance in smoking prevalence is relatively well documented. The aim of this study is to estimate levels of smoking persistence across 21 countries with a hypothesized inverse relationship between country income level and smoking persistence. METHODS: Data from the World Health Organization World Mental Health Survey Initiative were used to estimate cross-national differences in smoking persistence--the proportion of adults who started to smoke and persisted in smoking by the date of the survey. RESULTS: There is large variation in smoking persistence from 25% (Nigeria) to 85% (China), with a random-effects meta-analytic summary estimate of 55% with considerable cross-national variation. (Cochran's heterogeneity Q statistic = 6845; p < 0.001). Meta-regressions indicated that observed differences are not attributable to differences in country's income level, age distribution of smokers, or how recent the onset of smoking began within each country. CONCLUSION: While smoking should remain an important public health issue in any country where smokers are present, this report identifies several countries with higher levels of smoking persistence (namely, China and India).

Tinnitus in the elderly: Profile, correlates, and impact in the Nigerian Study of Ageing.

OBJECTIVE: To determine the prevalence and correlates of tinnitus among community elderly and its impact on their quality of life. STUDY DESIGN: Longitudinal cohort. SETTING: Yoruba-speaking communities in Nigeria. SUBJECTS AND METHODS: Face-to-face interviews of 1302 subjects 65 years or older selected by the use of a multistage stratified sampling of households. Subjects were assessed for subjective tinnitus, chronic health conditions, functional impairment, and quality of life by use of the brief version of the World Health Organization quality of life instrument. RESULTS: Tinnitus was reported in 184 (110 female and 74 male subjects), giving a prevalence of 14.1 percent (SE = 0.49). Gender, age, economic status, educational level, residence, smoking, and alcohol consumption were not significantly associated with tinnitus. Univariate analysis revealed a history of recurrent otitis media (odds ratio [OR] = 4.5, 95% confidence interval [95% CI] 3.1-6.6, P = 0.01), head injury (OR 3.4, 95% CI 2.1-5.6, P = 0.01), rhinosinusitis (OR 2.4, 95% CI 1.5-4.0, P = 0.01), dizziness (OR 2.1, 95% CI 1.4-3.1, P = 0.01), and hypertension (OR 1.7, 95% CI 1.0-2.7, P = 0.05) as significant correlates. However, in multivariate analysis, only a history of otitis media and of head injury remained significant. Compared with those without, persons with tinnitus had a more negative perception of their overall health and a poorer quality of life as well as twofold likelihood to experience impairment in both activities of daily living and instrumental activities of daily living. CONCLUSION: Tinnitus is common among elderly Nigerians and is associated with treatable health conditions, such as otitis media, rhinosinusitis, head injury, and hypertension. Its association with functional impairment and reduced quality of life highlights the need for inclusion in any comprehensive health care for the elderly.

Early cannabis use and estimated risk of later onset of depression spells: Epidemiologic evidence from the population-based World Health Organization World Mental Health Survey Initiative.

Early-onset cannabis use is widespread in many countries and might cause later onset of depression. Sound epidemiologic data across countries are missing. The authors estimated the suspected causal association that links early-onset (age <17 years) cannabis use with later-onset (age > or =17 years) risk of a depression spell, using data on 85,088 subjects from 17 countries participating in the population-based World Health Organization World Mental Health Survey Initiative (2001-2005). In all surveys, multistage household probability samples were evaluated with a fully structured diagnostic interview for assessment of psychiatric conditions. The association between early-onset cannabis use and later risk of a depression spell was studied using conditional logistic regression with local area matching of cases and controls, controlling for sex, age, tobacco use, and other mental health problems. The overall association was modest (controlled for sex and age, risk ratio = 1.5, 95% confidence interval: 1.4, 1.7), was statistically robust in 5 countries, and showed no sex difference. The association did not change appreciably with statistical adjustment for mental health problems, except for childhood conduct problems, which reduced the association to nonsignificance. This study did not allow differentiation of levels of cannabis use; this issue deserves consideration in future research.

Evaluating the drug use "gateway" theory using cross-national data: consistency and associations of the order of initiation of drug use among participants in the WHO World Mental Health Surveys.

BACKGROUND: It is unclear whether the normative sequence of drug use initiation, beginning with tobacco and alcohol, progressing to cannabis and then other illicit drugs, is due to causal effects of specific earlier drug use promoting progression, or to influences of other variables such as drug availability and attitudes. One way to investigate this is to see whether risk of later drug use in the sequence, conditional on use of drugs earlier in the sequence, changes according to time-space variation in use prevalence. We compared patterns and order of initiation of alcohol, tobacco, cannabis, and other illicit drug use across 17 countries with a wide range of drug use prevalence. METHOD: Analyses used data from World Health Organization (WHO) World Mental Health (WMH) Surveys, a series of parallel community epidemiological surveys using the same instruments and field procedures carried out in 17 countries throughout the world. RESULTS: Initiation of "gateway" substances (i.e. alcohol, tobacco and cannabis) was differentially associated with subsequent onset of other illicit drug use based on background prevalence of gateway substance use. Cross-country differences in substance use prevalence also corresponded to differences in the likelihood of individuals reporting a non-normative sequence of substance initiation. CONCLUSION: These results suggest the "gateway" pattern at least partially reflects unmeasured common causes rather than causal effects of specific drugs on subsequent use of others. This implies that successful efforts to prevent use of specific "gateway" drugs may not in themselves lead to major reductions in the use of later drugs.

Smoking estimates from around the world: data from the first 17 participating countries in the World Mental Health Survey Consortium.

OBJECTIVE: To contribute new multinational findings on basic descriptive features of smoking and cessation, based upon standardised community surveys of adults residing in seven low-income and middle-income countries and 10 higher-income countries from all regions of the world. METHODS: Data were collected using standardised interviews and community probability sample survey methods conducted as part of the WHO World Mental Health Surveys Initiative. Demographic and socioeconomic correlates of smoking are studied using cross-tabulation and logistic regression approaches. Within-country sample weights were applied with variance estimation appropriate for complex sample survey designs. RESULTS: Estimated prevalence of smoking experience (history of ever smoking) and current smoking varied across the countries under study. In all but four countries, one out of every four adults currently smoked. In higher-income countries, estimated proportions of former smokers (those who had quit) were roughly double the corresponding estimates for most low-income and middle-income countries. Characteristics of smokers varied within individual countries, and in relation to the World Bank's low-medium-high gradient of economic development. In stark contrast to a sturdy male-female difference in the uptake of smoking seen in each country, there is no consistent sex-associated pattern in the odds of remaining a smoker (versus quitting). CONCLUSION: The World Mental Health Surveys estimates complement existing global tobacco monitoring efforts. The observed global diversity of associations with smoking and smoking cessation underscore reasons for implementation of the Framework Convention on Tobacco Control provisions and prompt local adaptation of prevention and control interventions.

Prevalence rates for dementia and Alzheimer's disease in African Americans: 1992 versus 2001.

BACKGROUND: This study compares age-specific and overall prevalence rates for dementia and Alzheimer's disease (AD) in two nonoverlapping, population-based cohorts of elderly African Americans in Indianapolis in 2001 and 1992. METHODS: We used a two-stage design. The first stage involves the Community Screening Interview for Dementia (CSI-D). The CSI-D scores are grouped into good, intermediate, and poor performance before selection for clinical assessment. Diagnoses were performed using standard criteria in a consensus diagnosis conference; clinicians were blind to performance groups. In 1992, interviewers visited randomly sampled addresses to enroll self-identified African Americans aged > or =65 years. Of 2582 eligible, 2212 enrolled (9.6% refused, and 4.7% were too sick). In 2001, Medicare rolls were used for African Americans aged >70 years. Of 4260 eligible, 1892 (44%) enrolled, 1999 (47%) refused, and the remainder did not participate for other reasons. RESULTS: The overall age-adjusted prevalence rate for dementia at age > or =70 years in 2001 was 7.45% (95 confidence interval [CI], 4.27-10.64), and in the 1992 cohort, this prevalence rate was 6.75% (95% CI, 5.77-7.74). The overall age-adjusted prevalence rate at age > or =70 years for AD in the 2001 cohort was 6.77% (95% CI, 3.65-9.90), and for the 1992 cohort, it was 5.47% (95% CI, 4.51-6.42). Rates for dementia and AD were not significantly different in the two cohorts (dementia, P = .3534; AD, P = .2649). CONCLUSIONS: We found no differences in the prevalence rates of dementia and AD between 1992 and 2001, despite significant differences in medical history and medical treatment within these population-based cohorts of African American elderly.

Toward a global view of alcohol, tobacco, cannabis, and cocaine use: findings from the WHO World Mental Health Surveys.

BACKGROUND: Alcohol, tobacco, and illegal drug use cause considerable morbidity and mortality, but good cross-national epidemiological data are limited. This paper describes such data from the first 17 countries participating in the World Health Organization's (WHO's) World Mental Health (WMH) Survey Initiative. METHODS AND FINDINGS: Household surveys with a combined sample size of 85,052 were carried out in the Americas (Colombia, Mexico, United States), Europe (Belgium, France, Germany, Italy, Netherlands, Spain, Ukraine), Middle East and Africa (Israel, Lebanon, Nigeria, South Africa), Asia (Japan, People's Republic of China), and Oceania (New Zealand). The WHO Composite International Diagnostic Interview (CIDI) was used to assess the prevalence and correlates of a wide variety of mental and substance disorders. This paper focuses on lifetime use and age of initiation of tobacco, alcohol, cannabis, and cocaine. Alcohol had been used by most in the Americas, Europe, Japan, and New Zealand, with smaller proportions in the Middle East, Africa, and China. Cannabis use in the US and New Zealand (both 42%) was far higher than in any other country. The US was also an outlier in cocaine use (16%). Males were more likely than females to have used drugs; and a sex-cohort interaction was observed, whereby not only were younger cohorts more likely to use all drugs, but the male-female gap was closing in more recent cohorts. The period of risk for drug initiation also appears to be lengthening longer into adulthood among more recent cohorts. Associations with sociodemographic variables were consistent across countries, as were the curves of incidence of lifetime use. CONCLUSIONS: Globally, drug use is not distributed evenly and is not simply related to drug policy, since countries with stringent user-level illegal drug policies did not have lower levels of use than countries with liberal ones. Sex differences were consistently documented, but are decreasing in more recent cohorts, who also have higher levels of illegal drug use and extensions in the period of risk for initiation.