John Macleod

Psychological and social sequelae of cannabis and other illicit drug use by young people: a systematic review of longitudinal, general population studies

BACKGROUNDnUse of illicit drugs, particularly cannabis, by young people is widespread and is associated with several types of psychological and social harm. These relations might not be causal. Causal relations would suggest that recreational drug use is a substantial public health problem. Non-causal relations would suggest that harm-reduction policy based on prevention of drug use is unlikely to produce improvements in public health. Cross-sectional evidence cannot clarify questions of causality; longitudinal or interventional evidence is needed. Past reviews have generally been non-systematic, have often included cross-sectional data, and have underappreciated the extent of methodological problems associated with interpretation.nnnMETHODSnWe did a systematic review of general population longitudinal studies reporting associations between illicit drug use by young people and psychosocial harm.nnnFINDINGSnWe identified 48 relevant studies, of which 16 were of higher quality and provided the most robust evidence. Fairly consistent associations were noted between cannabis use and both lower educational attainment and increased reported use of other illicit drugs. Less consistent associations were noted between cannabis use and both psychological health problems and problematic behaviour. All these associations seemed to be explicable in terms of non-causal mechanisms.nnnINTERPRETATIONnAvailable evidence does not strongly support an important causal relation between cannabis use by young people and psychosocial harm, but cannot exclude the possibility that such a relation exists. The lack of evidence of robust causal relations prevents the attribution of public health detriments to illicit drug use. In view of the extent of illicit drug use, better evidence is needed.

Psychological stress and cardiovascular disease: empirical demonstration of bias in a prospective observational study of Scottish men.

Abstract Objectives: To examine the association between self perceived psychological stress and cardiovascular disease in a population where stress was not associated with social disadvantage. Design: Prospective observational study with follow up of 21 years and repeat screening of half the cohort 5 years from baseline. Measures included perceived psychological stress, coronary risk factors, self reported angina, and ischaemia detected by electrocardiography. Setting: 27 workplaces in Scotland. Participants: 5606 men (mean age 48 years) at first screening and 2623 men at second screening with complete data on all measures Main outcome measures: Prevalence of angina and ischaemia at baseline, odds ratio for incident angina and ischaemia at second screening, rate ratios for cause specific hospital admission, and hazard ratios for cause specific mortality. Results: Both prevalence and incidence of angina increased with increasing perceived stress (fully adjusted odds ratio for incident angina, high versus low stress 2.66, 95% confidence interval 1.61 to 4.41; P for trend <0.001). Prevalence and incidence of ischaemia showed weak trends in the opposite direction. High stress was associated with a higher rate of admissions to hospital generally and for admissions related to cardiovascular disease and psychiatric disorders (fully adjusted rate ratios for any general hospital admission 1.13, 1.01 to 1.27, cardiovascular disease 1.20, 1.00 to 1.45, and psychiatric disorders 2.34, 1.41 to 3.91). High stress was not associated with increased admission for coronary heart disease (1.00, 0.76-1.32) and showed an inverse relation with all cause mortality, mortality from cardiovascular disease, and mortality from coronary heart disease, that was attenuated by adjustment for occupational class (fully adjusted hazard ratio for all cause mortality 0.94, 0.81 to 1.11, cardiovascular mortality 0.91, 0.78 to 1.06, and mortality from coronary heart disease 0.98, 0.75 to 1.27). Conclusions: The relation between higher stress, angina, and some categories of hospital admissions probably resulted from the tendency of participants reporting higher stress to also report more symptoms. The lack of a corresponding relation with objective indices of heart disease suggests that these symptoms did not reflect physical disease. The data suggest that associations between psychosocial measures and disease outcomes reported from some other studies may be spurious. What is already known on this topic Higher psychological stress has predicted coronary heart disease in several observational studies Exposure to stress and heart disease outcomes were often based on self report so that a general tendency to negative perceptions may have generated a spurious association between higher perceived stress and heart disease symptoms What this study adds Perceived stress was strongly related to subjective symptoms of heart disease, including those leading to hospital admission However, stress showed a weakly inverse relation to all objective indices of heart disease: socially advantaged men perceived themselves to be most stressed, and the “protective” effect of stress was probably attributable to residual confounding Suggestions that psychological stress is an important determinant of heart disease may be premature

Sleep duration and mortality: the effect of short or long sleep duration on cardiovascular and all-cause mortality in working men and women

BACKGROUNDnThere is evidence to suggest that insufficient sleep may have an adverse effect on physical and psychological health. Previous studies have reported that when adjusting for major risk factors for cardiovascular disease and a number of demographic and social variables, sleeping 7-8 h each night is associated with lower mortality. These studies, however, have excluded any consideration of stress, which is known to be related to a number of behavioural risk factors for disease and, like sleep, may influence neurochemical, hormonal and immunological functioning.nnnMETHODSnThis study revisits the associations between sleep duration, cardiovascular disease risk factors and mortality, taking into account the perceived stress of individuals. The data come from a cohort of working Scottish men and women recruited between 1970 and 1973; approximately half of the cohort was screened for a second time, 4-7 years after the baseline examination.nnnRESULTSnFor both men and women, higher self-perceived stress was associated with a reduction in the hours of sleep reported. The pattern of mortality from all causes and the pattern of mortality from cardiovascular disease were consistent for both men and women. When sleep was measured on one occasion only, the risk of dying was reduced for men sleeping more than 8 h in every 24 h compared with those sleeping 7-8 h over the same period. This was after adjustment had been made for age, marital status, social class, cardiovascular risk factors and stress. The risk of dying was increased for women sleeping less than 7 h in every 24 h compared with those sleeping 7-8 h over the same period, after similar adjustments. When the data from the 1st and 2nd screening were considered longitudinally, both men and women who reported that they slept less than 7 h on both occasions that they were questioned, had a greater risk of dying from any cause than those who had reported sleeping 7-8 h at both screenings, after adjusting for age, marital status, social class and stress.nnnCONCLUSIONSnShort sleep over a prolonged period may be associated with an increased risk of mortality: men and women who reported sleeping fewer than 7 h in 24 on two occasions between 4 and 7 years apart, had greater risk of dying from any cause over a 25 year period than those who reported sleeping 7-8 h on both occasions that they were questioned.

Psychosocial factors and public health: a suitable case for treatment?

Adverse psychosocial exposure or “misery” is associated with physical disease. This association may not be causal. Rather it may reflect issues of reverse causation, reporting bias, and confounding by aspects of the material environment typically associated with misery. A non-causal relation will not form the basis of effective public health interventions. This may be why psychosocial interventions have, so far, showed little effect on objective physical health outcomes. This paper reviews evidence for the “psychosocial hypothesis” and suggests strategies for clarifying these issues. It concludes that, although misery is clearly a bad thing as it erodes people’s quality of life, there is little evidence that psychosocial factors cause physical disease. In the absence of better evidence, suggestions that psychosocial interventions are needed to improve population physical health, in both absolute and relative terms, seem premature.

Are the effects of psychosocial exposures attributable to confounding? Evidence from a prospective observational study on psychological stress and mortality

STUDY OBJECTIVES To examine the association between perceived psychological stress and cause specific mortality in a population where perceived stress was not associated with material disadvantage. DESIGN Prospective observational study with follow up of 21 years and repeat screening of half the cohort five years from baseline. Measures included perceived psychological stress, coronary risk factors, and indices of lifecourse socioeconomic position. SETTING 27 workplaces in Scotland. PARTICIPANTS 5388 men (mean age 48 years) at first screening and 2595 men at second screening who had complete data on all measures. MAIN OUTCOME MEASURES Hazard ratios for all cause mortality and mortality from cardiovascular disease (ICD9 390–459), coronary heart disease (ICD9 410–414), smoking related cancers (ICD9 140, 141, 143–9, 150, 157, 160–163, 188 and 189), other cancers (ICD9 140–208 other than smoking related), stroke (ICD9 430–438), respiratory diseases (ICD9 460–519) and alcohol related causes (ICD9 141, 143–6, 148–9, 150, 155, 161, 291, 303, 571 and 800–998). RESULTS At first screening behavioural risk (higher smoking and alcohol consumption, lower exercise) was positively associated with stress. This relation was less apparent at second screening. Higher stress at first screening showed an apparent protective relation with all cause mortality and with most categories of cause specific mortality. In general, these estimates were attenuated on adjustment for social position. This pattern was also seen in relation to cumulative stress at first and second screening and with stress that increased between first and second screening. The pattern was most striking with regard to smoking related cancers: relative risk high compared with low stress at first screening, age adjusted 0.64 (95% CI 0.42, 0.96), p for trend 0.016, fully adjusted 0.69 (95% CI 0.45, 1.06), p for trend 0.10; high compared with low cumulative stress, age adjusted 0.69 (95% CI 0.44, 1.09), p for trend 0.12, fully adjusted 0.76 (95% CI 0.48, 1.21), p for trend 0.25; increased compared with decreased stress, age adjusted 0.65 (95% CI 0.40, 1.06), p for trend 0.09, fully adjusted 0.65 (95% CI 0.40, 1.06), p for trend 0.08. CONCLUSIONS This implausible protective relation between higher levels of stress, which were associated with increased smoking, and mortality from smoking related cancers, was probably a product of confounding. Plausible reported associations between psychosocial exposures and disease, in populations where such exposures are associated with material disadvantage, may be similarly produced by confounding, and of no causal significance.

Is socioeconomic status in early life associated with drug use? A systematic review of the evidence

AIMnTo conduct a systematic review of longitudinal studies that examined the association between childhood socioeconomic status (SES) and illegal drug use in later life.nnnDESIGN AND METHODSnSystematic search with an agreed list of search items was used to identify all longitudinal population-based studies that examined the association between childhood SES and later drug use. These included MEDLINE (1966-2005), EMBASE (1990-2005), CINAHL (1982-2005) and PsychInfo (1806-2005), and specialist databases of the Lindesmith Library, Drugscope and Addiction Abstracts. Foreign-language papers were included. Abstracts were screened independently by two reviewers. If there was disagreement to accept or reject the abstract, then a third reviewer acted as arbiter. Data were extracted by one of the authors.nnnRESULTSnEleven relevant papers were identified (two birth cohorts and nine papers on school-aged cohorts). There was consistent evidence to support an association between lower childhood SES and later drug use, primarily cannabis use. However, few studies examined cannabis dependence, and studies of more problematic forms of drug use gave contradictory results.nnnDISCUSSION AND CONCLUSIONSnWe found consistent, though weak, evidence to support the assumption that childhood disadvantage is associated with later cannabis use. Further research is needed to clarify this issue and to inform future policies and public health messages.

Perceived stress and coronary heart disease risk factors: The contribution of socio-economic position

OBJECTIVESnThe aim of this study was to explore the relationship between risk factors for coronary heart disease (CHD) and perceived stress, adjusted for socio-economic position.nnnDESIGNnCross-sectional analysis of CHD risk factors, perceived stress and socio-economic position.nnnMETHODnA cohort of employed Scottish men (N = 5848) and women (N = 984) completed a questionnaire and attended a physical examination.nnnRESULTSnHigher socio-economic groups registered higher perceived stress scores. Perceived stress was associated with the following CHD risk factors in the expected direction: high plasma cholesterol, little recreational exercise, cigarette smoking, and high alcohol consumption. Contrary to expectations, stress was related negatively to high diastolic blood pressure, body mass index (BMI) and low forced expiratory volume. Correction for socio-economic position tended to abolish the associations between stress and physiological risk factors; the associations between stress and behavioural risk factors withstood such correction. The residual patterns of associations between perceived stress and CHD risk were broadly similar for men and women. A lower BMI, a greater number of cigarettes smoked, and greater alcohol consumption were associated with higher levels of perceived stress for both sexes. Lower levels of recreational exercise were associated with higher levels of stress for men only.nnnCONCLUSIONSnSelf-reported stress is related to health-related behaviours and to physiological CHD risk factors. The direction of the association with physiological risk was often contrary to expectation and appeared to be largely due to confounding by socio-economic position. In contrast, the association with health-related behaviours was in the expected direction and was largely independent of such confounding.

The socioeconomic position of employed women, risk factors and mortality

Many studies have demonstrated the graded association between socioeconomic position and health. Few of these studies have examined the cumulative effect of socioeconomic position throughout the lifecourse, and even fewer have included women. Those that have explored gender differences affirm the importance of studying the factors that predict women and mens health separately. This study addresses the associations between cross-sectional and longitudinal socioeconomic position, risk factors for cardiovascular disease and mortality from various causes. Analyses are based on data from a cohort of working Scottish women recruited between 1970 and 1973. Five socioeconomic measures were explored in relation to diastolic blood pressure, plasma cholesterol concentration, body mass index, forced expiratory volume in 1 s (FEV1). amount of recreational exercise taken, cigarette smoking and alcohol consumption. In general, for each of the five measures of socioeconomic position, there were significant differences in at least one of the age-adjusted physiological risk factors for cardiovascular disease (diastolic blood pressure, plasma cholesterol concentration, body mass index, FEV1). There were also significant differences in the percentage of current cigarette smokers according to different measures of socioeconomic position, although this was not the case for the other behavioural risk factors for cardiovascular disease (amount of recreational exercise taken, and alcohol consumption). Measures of socioeconomic position were also examined in relation to cause of death for the women who died before 1 January 1999. After adjusting for age and risk factors, a composite measure of lifetime socioeconomic experience was a more potent predictor of all cause mortality and mortality from cardiovascular disease than other measures of socioeconomic position. It therefore seems that conventional measurcs of socioeconomic position, estimated at one point in time, do not adequately capture the effects of socioeconomic circumstances on the risk of mortality among employed women. Thus, a broader range of explanatory factors for mortality differentials than currently exists must be considered, and must include consideration of factors operating throughout the lifecourse.

Change in job satisfaction, and its association with self-reported stress, cardiovascular risk factors and mortality.

Many studies have suggested that occupational stress may be related to the development of cardiovascular disease (CVD), independently of other known risk factors. Despite the recognition of job satisfaction as a particular form of stress, however, few studies have examined its association with CVD. Those studies that have explored the associations between job satisfaction and CVD risk factors, or job satisfaction and CVD mortality, have been largely cross-sectional in approach and report contradictory findings. This study revisits the associations between job satisfaction, self-reported stress. CVD risk factors and CVD mortality using longitudinal data from a cohort of working Scottish men and women recruited between 1970 and 1973. Approximately half of the cohort was screened for a second time, 4-7yr after the baseline examination. Job satisfaction at baseline was strongly associated with low or moderate perceived stress at 2nd screening. Men and women reporting decreased satisfaction in their jobs between baseline and 2nd screening tended to report moderate or high perceived stress at 2nd screening. Job satisfaction was associated with own occupational class in different directions for men and women. Men in the manual social classes reported more satisfaction with their jobs than their peers, whilst it was women in the non-manual social classes who reported more satisfaction with their jobs than their peers. There was limited evidence of an association between job satisfaction and age-adjusted CVD risk factors (diastolic blood pressure; blood cholesterol; body mass index; forced expiratory volume in 1st amount of recreational exercise undertaken; cigarette smoking and alcohol consumption) for men, after adjustment for occupational class, but there was no evidence of any association for women. There was also no evidence to suggest that men or women reporting job dissatisfaction on one occasion or on two occasions several years apart, had a significantly greater risk of mortality from CVD.

Cost effectiveness of home based population screening for Chlamydia trachomatis in the UK: economic evaluation of chlamydia screening studies (ClaSS) project

Objective To investigate the cost effectiveness of screening for Chlamydia trachomatis compared with a policy of no organised screening in the United Kingdom. Design Economic evaluation using a transmission dynamic mathematical model. Setting Central and southwest England. Participants Hypothetical population of 50u2009000 men and women, in which all those aged 16-24 years were invited to be screened each year. Main outcome measures Cost effectiveness based on major outcomes averted, defined as pelvic inflammatory disease, ectopic pregnancy, infertility, or neonatal complications. Results The incremental cost per major outcome averted for a programme of screening women only (assuming eight years of screening) was �22u2009300 (€33u2009000;