Lifestyle Factors Associated With Frequent Recurrent Headaches in Children and Adolescents: A Canadian Population-Based Study.

BACKGROUND AND OBJECTIVES: Lifestyle behaviors have been postulated to affect headache frequency in youth and are often the primary target of self-management recommendations. Our study aimed to assess the association between various lifestyle factors and frequent recurrent headaches in children and youth. METHODS: Children and adolescents aged 5-17 years were enrolled in a large cross-sectional Canadian population-based health survey, completed on January 31, 2019. Headache frequency was dichotomized into "approximately once/week or less" or ">once/week" (defined as frequent recurrent headaches). The association between frequent headaches and meal schedules, screen exposure, physical activity, chronotype, and frequent substance use/exposure (alcohol, cigarettes, electronic cigarettes, and cannabis) was assessed using both unadjusted logistic regression models and models adjusted for age/sex. Fully adjusted models examined the odds of frequent headaches according to all exposures. Survey design effects were accounted for using bootstrap replicate weighting. RESULTS: There were an estimated nweighted = 4,978,370 eligible participants in the population. The mean age was 10.9 years (95% CI 10.9-11.0); 48.8% were female; 6.1% had frequent headaches. Frequent headaches were associated with older age (odds ratio [OR] = 1.31, 95% CI 1.28-1.34, p < 0.001) and female sex (OR = 2.39, 95% CI 2.08-2.75, p < 0.001). In models adjusted for age/sex, the odds of frequent headaches decreased with meal regularity (adjusted OR [aOR] = 0.90, 95% CI 0.89-0.92, p < 0.001) and increased with later chronotype (aOR = 1.10, 95% CI 1.05-1.15, p < 0.001) and excess screen exposure (≥21 hours vs none in past week: aOR = 2.97, 95% CI 1.53-5.77, p = 0.001); there was no significant association with reported physical activity (aOR = 0.95, 95% CI 0.67-1.34, p = 0.77). In 12- to 17-year-olds, frequent headaches were associated with frequent alcohol use (≥1/wk vs never: aOR = 3.50, 95% CI 2.18-5.62, p < 0.001), binge drinking (≥5 times in past month vs never: aOR = 5.52, 95% CI 2.95-10.32, p < 0.001), smoking cigarettes (daily vs never: aOR = 3.81, 95% CI 1.91-7.62, p < 0.001), using e-cigarettes (daily vs never: aOR = 3.10, 95% CI 2.29-4.20, p < 0.001), and cannabis use (daily vs never: aOR = 3.59, 95% CI 2.0-6.45, p < 0.001). In the entire sample, daily exposure to smoking inside the house was associated with frequent headaches (aOR = 2.00, 95% CI 1.23-3.27, p = 0.005). DISCUSSION: Several lifestyle behaviors were associated with frequent headaches in children and youth, such as meal irregularity, late chronotype, prolonged screen exposure, and frequent substance use/exposure, suggesting that these are potential modifiable risk factors to target in this population.

Trends in vaping and smoking behavior before and during the COVID-19 pandemic in Canada: Beneficial and potentially detrimental changes.

INTRODUCTION: E-cigarette and cigarette use may have changed during the COVID-19 pandemic, however, there is no consensus in existing literature, and current Canadian studies have not used representative samples. Thus, there is a need for robust national estimates. OBJECTIVE AND METHODS: The primary objective was to describe the 30-day period prevalence of smoking and vaping before and during the COVID-19 pandemic in Canada. This study analyzed three years of the cross-sectional Canadian Tobacco and Nicotine Survey: 2019 (pre-pandemic), 2020 (9 months into the pandemic) and 2021 (21 months into pandemic). RESULTS: Thirty-day period prevalence of vaping over the 2019, 2020, and 2021 study periods were 4.8 (95%CI: 4.2-5.3), 4.6% (95%CI: 4.1-5.2), and 5.2% (95%CI: 4.7-5.7), respectively. The 30-day period prevalence of smoking over the 2019, 2020, and 2021 study periods were 11.9% (95%CI: 10.9-12.7), 10.3% (95%CI: 9.4-11.2), and 10.3% (95%CI: 9.4-11.1), respectively. Notably, estimates of smoking for females decreased considerably from 2019 (11.0%; 95%CI: 9.9--12.2%) to 2020 (8.6%; 95%CI: 7.5-9.7). Estimates of vaping in those aged 20-24 increased substantially from 2020 (13.0%; 95%CI: 10.9-15.1) to 2021 (17.2%; 95%CI: 15.4-18.9). CONCLUSIONS: Changes to smoking and vaping were restricted to subsets within the population. In those aged 20-24, there was a modest increase in vaping from 2020 to 2021. In females, there was a decrease in smoking from 2019 to 2020, which persisted in 2021.

Cancer risk, disease-modifying therapy, and age in multiple sclerosis: A retrospective population-based cohort study.

BACKGROUND: Long-term population-based safety studies are needed to investigate cancer outcomes in people with multiple sclerosis (MS) treated with modern disease-modifying therapy (DMT). OBJECTIVES: To investigate if exposure to DMT increases the risk of invasive cancer in MS. METHODS: We used population-based administrative health data from Alberta, Canada between 2008 and 2018. DMT exposure was defined in two ways: first as exposure to any DMT, and second by DMT type (modulating, sequestering, depleting). Study outcome was time to first diagnosis of invasive cancer. Cancer risk was compared to the general population using standardized incidence ratios (SIRs) and to the unexposed MS cases using hazard ratios (HRs). RESULTS: The analysis included 14,313 MS cases: 5,801 (40.5 %) were exposed to DMT. Median (interquartile range) follow-up was 8.4 (4.3, 10.4) years. Compared to the general population, there was no difference in cancer risk for the overall MS population (SIR: 0.94, 95 % confidence interval [CI]: 0.87, 1.02) or the DMT-exposed MS cases (SIR: 0.89; 95 % CI: 0.75, 1.05). Compared to unexposed MS cases, we found an interaction with age for exposure to any DMT (p = 0.001) and modulating DMT (p = 0.001), indicating that a difference in the risk of cancer associated with DMT depends on age. Cancer risk was not associated with exposure to sequestering DMT (HR: 1.28, 95 % CI: 0.78, 2.08) or depleting DMT (HR: 2.29, 95 % CI: 0.86, 6.14). CONCLUSIONS: Cancer risk for MS patients was similar to the general population. In the MS population, the age-dependent effect of DMT for cancer risk suggests a higher risk of cancer with age 62 or older and a protective effect at younger age. Further investigation is required to clarify whether the interaction between DMT exposure and age is a causal effect.

Association Between Excess Sleep Duration and Risk of Stroke: A Population-Based Study.

BACKGROUND: Excess sleep is associated with higher risk of stroke, but whether the risk is modified by age and if it remains elevated after accounting for the competing risk of death is not well understood. METHODS: We used nine years of the Canadian Community Health Survey between 2000 to 2016 to obtain self-reported sleep duration and created a cohort of individuals without prior stroke, heart disease, or cancer. We linked to hospital records to determine subsequent admissions or emergency department visits for acute stroke until December 31, 2017. We used Cox proportional hazard models to determine the association between sleep duration and risk of stroke, assessing for modification by age and sex and adjusting for demographic, vascular, and social factors. We obtained cumulative incidence of stroke accounting for the competing risk of death. RESULTS: There were 82,795 individuals in our cohort who met inclusion criteria and had self-reported sleep duration, with 1705 stroke events in follow-up. There was an association between excess sleep (≥10 h/night) and risk of stroke in those <70 years (fully adjusted hazard ratio 2.29, 95% CI 1.04-5.06), but not ≥70 years of age, with a similar association after accounting for the competing risk of death. CONCLUSION: Sleep duration ≥10 h/night is associated with increased risk of stroke in those <70 years of age. The findings support current guidelines for 7-9 h of sleep per night. Further research is needed to elucidate the relationship between sleep and cerebrovascular disease.

Alternative scoring of the Patient Health Questionnaire-9 in neurological populations: an approach based on a predictive algorithm deriving from individual item scores.

OBJECTIVE: The study objective was to assess whether machine learning methods could improve predictive performance of the PHQ-9 for depression in patients with neurological disease. Specifically, we assessed whether a predictive algorithm deriving from all nine items could outperform the tradition of summing the items and applying a cut-point. METHOD: Data from the NEEDS Study was used (n = 825). Demographic data, PHQ-9 scores, and MDD diagnoses (via the SCID) were obtained. Logistic LASSO, logistic regression, and non-parametric ROC analyses were performed. The ROC curve was used to identify the optimal cut-point for regression-derived predictive algorithms using the Youden method. RESULTS: The traditional approach to PHQ-9 scoring had a classification accuracy of 85.1% (sensitivity: 84.5%; specificity: 85.2%). The logistic LASSO regression model had a classification accuracy of 85.6% (sensitivity: 83.3%; specificity: 86.1%). The logistic regression model had a classification accuracy of 85.8% (sensitivity: 91.4%; specificity: 84.8%). Both models had similar areas under the curve values (logistic LASSO: 0.9097; logistic regression: 0.9026). CONCLUSIONS: The current cut-off threshold approach to PHQ-9 scoring and interpretation remains clinically appropriate.

Vascular risk factors and stroke risk across the life span: A population-representative study of half a million people.

BACKGROUND: The incidence of stroke in developed countries is increasing selectively in young individuals, but whether this is secondary to traditional vascular risk factors is unknown. METHODS: We used the Canadian Community Health Survey from 2000 to 2016 to create a large population-representative cohort of individuals over the age of 30 and free from prior stroke. All analyses were stratified by age decile. We linked with administrative databases to determine emergency department visits or hospitalizations for acute stroke until December 2017. We calculated time trends in risk factor prevalence (hypertension, diabetes, obesity, and smoking) using meta-regression. We used Cox proportional hazard models to evaluate the association between vascular risk factors and stroke risk, adjusted for demographic, co-morbid, and social variables. We used competing risk regression to account for deaths and calculated population-attributable fractions. In a sensitivity analysis, we excluded those with prior heart disease or cancer. RESULTS: We included 492,400 people in the analysis with 8865 stroke events over a median follow-up time of 8.3 years. Prevalence of hypertension, diabetes, and obesity increased over time while smoking decreased. Associations of diabetes, hypertension, and obesity with stroke risk were progressively stronger at younger age (adjusted hazard ratio for diabetes was 4.47, 95% confidence interval (CI) = 1.95-10.28 at age 30-39, vs 1.21, 95% CI = 0.93-1.57 at age 80+), although the obesity association was attenuated with adjustment. Smoking was associated with higher risk of stroke without a gradient across age deciles, although had the greatest population-attributable fraction at younger age. The hazard ratio for stroke with multiple concurrent risk factors was much higher at younger age (adjusted hazard ratio for 3-4 risk factors was 8.60, 95% CI = 2.97-24.9 at age 30-39 vs 1.61, 95% CI = 0.88-2.97 at age 80+) and results were consistent when accounting for the competing risk of death and excluding those with prior heart disease or cancer. CONCLUSIONS: Diabetes and hypertension were associated with progressively elevated relative risk of stroke in younger individuals and prevalence was increasing over time. The association of obesity with stroke was not significant after adjustment for other factors. Smoking had the greatest prevalence and population-attributable fraction for stroke at younger age. Our findings assist in understanding the relationship between vascular risk factors and stroke across the life span and planning public health measures to lower stroke incidence in the young.

Association Between Excess Leisure Sedentary Time and Risk of Stroke in Young Individuals.

Background and Purpose: The association between physical activity (PA) and lower risk of stroke is well established, but the relationship between leisure sedentary time and stroke is less well studied. Methods: We used 9 years of the Canadian Community Health Survey between 2000 and 2012 to create a cohort of healthy individuals without prior stroke, heart disease, or cancer. We linked to hospital records to determine subsequent hospitalization or emergency department visit for stroke until December 31, 2017. We quantified the association between self-reported leisure sedentary time (categorized as <4, 4 to <6, 6 to <8, and 8+ hours/day) and risk of stroke using Cox regression models and competing risk regression, assessing for modification by PA, age, and sex and adjusting for demographic, vascular, and social factors. Results: There were 143 180 people in our cohort and 2965 stroke events in follow-up. Median time from survey response to stroke was 5.6 years. There was a 3-way interaction between leisure sedentary time, PA, and age. The risk of stroke with 8+ hours of sedentary time was significantly elevated only among individuals <60 years of age who were in the lowest PA quartile (fully adjusted hazard ratio, 4.50 [95% CI, 1.64­12.3]). The association was significant across multiple sensitivity analyses, including adjustment for mood disorders and when accounting for the competing risk of death. Conclusions: Excess leisure sedentary time of 8+ hours/day is associated with increased risk of long-term stroke among individuals <60 years of age with low PA. These findings support efforts to enhance PA and reduce sedentary time in younger individuals.

Outdoor Air Pollution and Depression in Canada: A Population-Based Cross-Sectional Study from 2011 to 2016.

To assess whether exposure to increased levels of outdoor air pollution is associated with psychological depression, six annual iterations of the Canadian Community Health Survey (n ≈ 127,050) were used to estimate the prevalence of a major depressive episode (2011-2014) or severity of depressive symptoms (2015-2016). Survey data were linked with outdoor air pollution data obtained from the Canadian Urban Environmental Health Research Consortium, with outdoor air pollution represented by fine particulate matter ≤2.5 micrometers (µm) in diameter (PM2.5), ozone (O3), sulfur dioxide (SO2), and nitrogen dioxide (NO2). Log-binomial models were used to estimate the association between outdoor air pollution and depression, and included adjustment for age, sex, marital status, income, education, employment status, urban versus rural households, cigarette smoking, and chronic illness. No evidence of associations for either depression outcomes were found. Given the generally low levels of outdoor air pollution in Canada, these findings should be generalized with caution. It is possible that a meaningful association with major depression may be observed in regions of the world where the levels of outdoor air pollution are greater, or during high pollution events over brief time intervals. Future research is needed to replicate these findings and to further investigate these associations in other regions and populations.

Cannabis Use and Internalizing/Externalizing Symptoms in Youth: A Canadian Population-Based Study.

PURPOSE: With the recent legalization of cannabis for nonmedicinal purposes in Canada, it is becoming increasingly important to understand the potential mental health risks that cannabis may present. The objective of this study was to estimate associations between the frequency of cannabis use and the presence of elevated internalizing (e.g., anxiety and depression) and externalizing (e.g., conduct disorder and attention deficit hyperactivity disorder) symptoms within Ontario youth aged 12-17 years. METHODS: The 2014 Ontario Child Health Study included Emotional and Behavioural Scales used to assess internalizing and externalizing symptoms. To assess associations between internalizing/externalizing symptoms and cannabis use, the Ontario Child Health Study-Emotional and Behavioural Scales were dichotomized using the upper quintile (those with the most severe symptoms). Logistic regression was used to estimate odds ratios (ORs) to quantify the association between the frequency of cannabis use and the presence of elevated internalizing and externalizing symptoms. Estimates used a recommended procedure (replicate bootstrap weighting) to address design effects. RESULTS: A significant association between frequent cannabis use and elevated externalizing symptoms was observed with an OR of 2.17 (1.80-2.62) in males and 5.13 (4.24-6.21) in females. Similar significant associations were also observed between frequent cannabis use and elevated internalizing symptoms with an OR of 2.07 (1.74-2.47) in males and an OR of 3.40 (2.73-4.24) in females. These associations were still present after adjusting for age, binge drinking, smoking, and negative/positive parenting. CONCLUSIONS: Cannabis use, especially in females and frequent users, is associated with elevated levels of internalizing and externalizing symptoms.

Electronic cigarette use and mental health: A Canadian population-based study.

BACKGROUND: To examine the association between electronic cigarette (e-cigarette) use and adverse mental health status. METHODS: A cross-sectional analysis was conducted using data from the 2015 and 2016 Canadian Community Health Survey (n = 53,050). Sampling weights and associated bootstrap procedures were used to account for survey design effects. Multivariable logistic regression was employed to examine the association between e-cigarette use and the following mental health outcomes: depressive symptom ratings (using the Patient Health Questionnaire 9), self-reported professionally diagnosed mood and anxiety disorders, perceived mental health, suicidal thoughts/attempts, and binge drinking. RESULTS: The overall prevalence of past 30-day e-cigarette use was 2.9% (95% CI: 2.6-3.1). 11.5% (95% CI: 10.4-12.7) of smokers reported also using e-cigarettes. Dual users had the highest prevalence of adverse mental health status. The association between e-cigarette use and mental health was found to be modified by smoking status and sex in most of the logistic models. E-cigarettes had less than multiplicative effects among smokers. Female e-cigarette users tended to have higher odds of adverse mental health than male users. Overall, in the multivariable modeling, e-cigarette use was consistently associated with poor mental health among non-smokers and women, a finding that persisted after adjustment for additional covariates. CONCLUSIONS: These results indicate that e-cigarette use is associated with adverse mental health status, particularly among the non-smoking general population and women. LIMITATIONS: The study relied on respondent self-report, and the cross-sectional nature of the study does not allow us to clarify the direction of this association.

Major depressive episodes and mortality in the Canadian household population.

OBJECTIVE: To explore the association between major depressive episodes (MDE) and subsequent mortality in a representative sample of the general household population, with adjustment for other determinants of mortality. METHOD: The analysis used four datasets from the Canadian Community Health Survey (CCHS); the CCHS 1.1 (conducted in 2000 and 2001), the CCHS 1.2 (conducted in 2002), the CCHS 2.1 (conducted in 2003 and 2004) and the CCHS 3.1 (conducted in 2005 and 2006). Each survey included an assessment of past-year major depressive episodes (MDEs) and was linked to mortality data from the Canadian Mortality Database for January 1, 2000 to December 31, 2011. The hazard ratio (HR) for all-cause mortality was estimated in each survey sample. Random effects, individual-level meta-analysis was used to pool estimates from the four survey data sets. Estimates were adjusted for other determinants of mortality prior to pooling in order to help quantify the independent contribution of MDE to all-cause mortality. RESULTS: The unadjusted HR was 0.77 (95% CI 0.63-0.95). A naïve interpretation of this HR suggests a protective effect of MDE, but the estimate was found to be strongly confounded by age (age adjusted HR for MDE: 1.61, 95% CI 1. 34-1.93) and by sex (sex adjusted HR for MDE: 1.15, 95% CI 0.75-1.77). The age and sex adjusted HR was: 1.70 (95% CI 1.45-2.00). No evidence of effect modification by any determinant of mortality was found, including sex. After adjustment for a set of mortality risk factors, the pooled HR was weakened, but remained statistically significant, HR = 1.29 (I-squared = < 1%, tau-squared < 0.001, 95% CI 1.10-1.51). Smoking was the strongest single confounding variable. CONCLUSIONS: MDE is associated with elevated mortality. The elevated risk is partially attributable to psychosocial, behavioral and health-related determinants. Since MDE itself may have caused changes to these variables, these estimates cannot fully quantify the independent contribution of MDE to mortality. However, these results suggest that clinical and public health efforts to counteract the effect of MDE on mortality may benefit from attention to a broad set of mortality risk factors e.g. smoking, physical activity, management of medical conditions.

Major depression and secondhand smoke exposure.

BACKGROUND: Epidemiological studies have consistently linked smoking to poor mental health. Among non-smokers, some studies have also reported associations between secondhand smoke exposure and psychological symptoms. However, an association between secondhand smoke exposure and depressive disorders has not been well established. METHODS: This analysis used cross-sectional data from a series of 10 population surveys conducted in Canada between 2003 and 2013. The surveys targeted the Canadian household population, included a brief structured interview for past year major depressive episode (MDE) and included items assessing secondhand smoke exposure. We used two-stage individual-level random-effects meta-regression to synthesize results from these surveys. RESULTS: Over the study interval, about 20% of non-smokers reported substantial exposure to secondhand smoke. In this group, the pooled annual prevalence of MDE was 6.1% (95% CI 5.3-6.9) compared to 4.0% (95% CI 3.7-4.3) in non-smokers without secondhand smoke exposure. The crude odds ratio was 1.5 (95% CI 1.4-1.7). With adjustment for a set of potential confounding variables the odds ratio was unchanged, 1.4 (95% CI 1.2 - 1.6). CONCLUSIONS: These results provide additional support for public health measures aimed at reducing secondhand smoke exposure. A causal connection between secondhand smoke exposure and MDEs cannot be confirmed due to the cross-sectional nature of the data. Longitudinal studies are needed to establish temporal sequencing.

Major depression and non-specific distress following smoking cessation in the Canadian general population.

BACKGROUND: Outcome data from smoking cessation trials indicate that improvement in mental health occurs after smoking cessation. This suggests that smoking cessation should be a priority for mental health services. However, participants in such trials may not be representative of the general population. This study investigates changes in mental health following smoking cessation in a set of general population samples. METHODS: Data from a library of cross-sectional surveys conducted by Statistics Canada between 2001 and 2013 were included in this analysis. Survey estimates were pooled in order to increase precision. Associations between smoking (and smoking cessation), major depressive episodes (MDE) and non-specific distress (assessed using the K-6 scale) were evaluated using meta-analysis and meta-regression techniques. RESULTS: The annual prevalence of major depression was higher in daily (11.0%) than in never smokers (4.4%). The prevalence in former daily smokers was 5.1%. The prevalence of MDE and distress was elevated in those recently quitting but returned to baseline levels within one year. CONCLUSIONS: After smoking cessation, indicators of mental health improve over time, especially in the first year. The findings support the idea that smoking cessation should be a part of the management of common mood and anxiety disorders. However, due to its observational nature this study in itself cannot confirm causality, sustained abstinence may be an effect of improved mental health rather than its cause. LIMITATIONS: The cross-sectional nature of the constituent surveys does not allow causal inference. No biological measures (e.g. cotinine) were available.

A comparison of recommendations and received treatment for mood and anxiety disorders in a representative national sample.

BACKGROUND: The exact nature of treatment and management recommendations made, and received, for mood and anxiety disorders in a community population is unclear. In addition, there is limited evidence on the impact of recommendations on actual receipt of treatment or implementation of management strategies. We aim to describe the frequency with which specific recommendations were made and implemented; and thus assess the size of any gap between the recommendation and implementation of treatments and management strategies. METHODS: We used the Survey 'Living with a Chronic Condition in Canada - Mood and Anxiety Disorders (SLCDC-MA), a unique crossectional survey of a large (N = 3358) and representative sample of Canadians with a diagnosed mood or anxiety disorder, which was conducted by Statistics Canada. The survey collected information on recommendations for medication, counselling, exercise, reduction of alcohol consumption, smoking cessation and reduction of street drug use. We also estimate the frequency that recommendations are made and followed, as well the impact of the prior on the latter. We consulted people with lived experience of the disorders to help interpret our results. RESULTS: The results generally showed that most people would receive recommendations, almost all for antidepressant medications (94.6%), with lower proportions for the other treatment and management strategies (e.g. 62.1 and 66% for counselling and exercise). Most recommendations were implemented and had an impact on behaviour. The exception to this was smoking reduction/cessation, which was often not recommended or followed through. Other than with medication, at least 20% of the population, for each recommendation, would not have their recommendation implemented. A substantive group also exists who access treatments, and employ various management strategies, without a recommendation. CONCLUSIONS: The results indicate that there is a gap between recommendations made and the implementation of treatments. However, its size varies substantially across treatments.

Depression--a common disorder across a broad spectrum of neurological conditions: a cross-sectional nationally representative survey.

OBJECTIVE: To estimate the prevalence of depression across a range of neurological conditions in a nationally representative sample. METHODS: The data source was the Survey of Living with Neurological Conditions in Canada (SLNCC), which accrued its sample by selecting participants from the Canadian Community Health Survey. The point prevalence of depression was estimated by assessment of depressive symptoms with the Patient Health Questionnaire, Brief (Patient Health Questionnaire, 9-item). RESULTS: A total of n=4408 participated in the SLNCC. The highest point prevalence of depression (>30%) was seen in those with traumatic brain injury and brain/spinal cord tumors. Depression was also highly prevalent (18-28%) in those with (listed from highest to lowest) Alzheimer's disease/dementia, dystonia, multiple sclerosis, Parkinson's disease, stroke, migraine, epilepsy and spina bifida. The odds ratios for depression, with the referent group being the general population, were significant (from highest to lowest) for migraine, traumatic brain injury, stroke, dystonia and epilepsy. CONCLUSIONS: All neurological conditions included in this study are associated with an elevated prevalence of depression in community populations. The conditions with the highest prevalence are traumatic brain injury and brain/spinal cord tumors.

Persistent heavy smoking as risk factor for major depression (MD) incidence--evidence from a longitudinal Canadian cohort of the National Population Health Survey.

BACKGROUND: Reports of bidirectional associations between smoking and major depression (MD) have been interpreted as providing evidence for confounding by shared-vulnerability factors (SV) that predispose individuals to both conditions. If this is true, then smoking cessation may not reduce the risk of MD. From clinical practice and public health perspectives, the long-term outcomes associated with smoking persistence and cessation are potentially important and deserve exploration. To this end, the 12-year risk of MD in persistent heavy smokers and abstainers who were former-heavy smokers with and without adjustment for potential confounders were compared. METHODS: Follow-up data from the National Population Health Survey (NPHS) was used. Multinomial logistic (ML) models were fit to identify potential confounders. Using proportional hazard (PH) models, unadjusted and adjusted hazard ratios (HRs) for MD outcome were estimated for different smoking patterns. RESULTS: The unadjusted HR relating the risk of MD among current-heavy versus former-heavy smokers was 4.3 (95% CI: 2.6-6.9, p < 0.001). Current-heavy smoking predicted onset of MD (HR = 3.1, 95% CI: 1.9-5.2, p < 0.001) even after adjustment for age, sex and stress - the main confounders. However, this was not the case for the never, former-light, and current-light categories. Evidence of decreased risk of MD among former-heavy relative to current-heavy smokers as function of smoking cessation maintenance time was also found. CONCLUSIONS: Contrary to common beliefs about the benefits of smoking for mental health, our results suggest that current-heavy rather than ever-heavy smoking is a major determinant of MD risk and point towards the benefits of smoking cessation maintenance.

Major depression is a risk factor for shorter time to first cigarette irrespective of the number of cigarettes smoked per day: evidence from a National Population Health Survey.

INTRODUCTION: We assessed whether major depression (MD) predicts progression of nicotine dependence (ND) as measured by reduction in the time to first cigarette (TTFC) after waking and the roles of the number of cigarettes smoked per day (CPD) and stress as explanatory variables of this association. METHODS: Ten years of follow-up data from the National Population Health Survey (NPHS) were used. The analyses were based on this nationally representative sample of the Canadian population who were over the age of 12 years in 1996 (n = 13,298). The NPHS included measures of MD and TTFC. Shorter TTFC was defined as TTFC within 5 min of waking. Heavy smoking (HS) was defined by smoking 20 or more CPD. Using proportional hazard models, unadjusted and adjusted hazard ratios (HRs) for shorter TTFC were estimated for those with and without MD. RESULTS: The unadjusted HR for shorter TTFC among those with MD versus those without MD was 3.7 (95% CI: 2.6-5.3, p < .001). MD predicted onset of shorter TTFC even after adjustment for HS and tendency to smoke more under stress (HR: 1.7; 95% CI: 1.1-2.5, p = .02). When TTFC was defined using longer cutoffs (30 and 60 min), HS completely accounted for the effect of MD on TTFC onset. CONCLUSIONS: MD appears to be a risk factor for transition to shorter TTFC independent of effects of HS and the tendency to smoke more under stress. As MD is often modifiable, the above association points toward a preventive opportunity in relation to worsening of ND.

Chronic conditions and major depression in community-dwelling older adults.

OBJECTIVES: To estimate (1) the prevalence of long-term medical conditions and of comorbid major depression, and (2) the associations between major depression and various chronic medical conditions in a general population of older adults (over 50 years of age) and in persons who are traditionally classified as seniors (65 years and older). METHODS: Data from the Canadian Community Health Survey- Mental Health and Wellbeing (CCHS-1.2) were analyzed. Non-institutionalized individuals over 15 years of age in the 10 Canadian provinces were sampled in the CCHS-1.2. The entire sample of the CCHS-1.2 consisted of 36,894 individuals, for the main analyses in this study the dataset was restricted to those aged 50 and over (n=15,591). Chronic health conditions were assessed using a self-report method of doctor diagnosis. The World Mental Health-Composite Diagnostic Interview was used to asses major depressive episodes based on DSM-IV criteria. RESULTS: The overall prevalence of having at least one chronic condition in those over 50 years of age was 82.4%, compared to 62.0% in those under 50. The prevalence of a major depressive episode in those over 50 with one chronic condition was 3.7%, compared with 1.0% in those without a long-term medical condition. The top 3 chronic health conditions in seniors aged 65 or older were arthritis/rheumatism, high blood pressure and back problems. Chronic Fatigue Syndrome, fibromyalgia and migraine headache had the highest comorbidity with major depression in the senior population. LIMITATIONS: The use of self-report data on chronic health conditions, potential diagnostic overlap between conditions, and the inability to make causal inferences due to the cross-sectional nature of the data are all limitations of the current study. CONCLUSIONS: Differences were found between rates of chronic conditions and major depression between the general population, older adults and seniors in this study. Further research is needed to delineate the direction of these relationships in seniors. Primary and secondary prevention efforts should target seniors who exhibit symptoms of depression or highly prevalent chronic health conditions.

Predictors of the longitudinal course of major depression in a Canadian population sample.

OBJECTIVE: Most psychiatric epidemiologic studies have used cross-sectional methods, resulting in a lack of information about the longitudinal course of depressive disorders. The objective of our study was to describe the longitudinal epidemiology of major depressive episodes (MDEs) in a Canadian sample using data from the National Population Health Survey (NPHS). METHODS: The NPHS started data collection in 1994 and has evaluated past-year MDE using repeat interviews of the same cohort every 2 years since then. In our study, we examined the number of weeks depressed during years when MDEs occurred, the proportion of respondents having MDEs at consecutive cycles, and MDE counts during follow-up. RESULTS: A sizable proportion of MDEs were brief: about one-half of respondents with past-year MDE reported 8 or fewer weeks of depression during that year. Less than 10% reported that they were depressed for the entire year. However, a larger proportion (19.1%) fulfilled criteria for MDE on consecutive interview cycles, suggesting either persistence or rapid recurrence. The mean number of detected MDEs among those with at least 1 detected MDE up to 2006 was 2. Positive family history, evidence of comorbidity, negative cognitive style, stress, pain, and smoking were associated with a more negative course. CONCLUSIONS: The longitudinal course of MDE in the general population is heterogeneous, including a mixture of brief and more protracted MDEs. Many risk factors for MDE are also associated with a negative course, exceptions being (younger) age and sex. These epidemiologic observations may assist with identification of patients requiring more intensive management in clinical practice.