The public health impact of antidepressants: An instrumental variable analysis

ArticleinJournal of Affective Disorders 134(1-3):188-97 · June 2011with17 Reads
Impact Factor: 3.38 · DOI: 10.1016/j.jad.2011.05.037 · Source: PubMed
  • 43.77 · Johns Hopkins Bloomberg School of Public Health

There has been a marked increase in antidepressant medication prescription and use over the past three decades with unclear effects on the mental health status of the population. This study examined the impact of expansion of antidepressant use on prevalence and characteristics of depression and suicidal ideations in the community. Instrumental variable models were used to assess the impact of antidepressant treatments on the prevalence of depressive episodes, mixed anxiety and depression states and suicidal ideations in 22,845 participants of the 1993, 2000 and 2007 National surveys of psychiatric morbidity of Great Britain who were between 16 and 64 years of age. Increased prevalence of antidepressant treatment did not impact the prevalence of depressive episodes or mixed anxiety and depression states. However, antidepressant treatment was associated with decreased prevalence of severe and, to a lesser extent, mild depressive episodes and suicidal ideations and a corresponding increase in prevalence of moderate depressive episodes. The data were cross-sectional and based on self-report of symptoms in the past month and current medication use with no information on dose and duration of medication treatment. Expansion of antidepressant treatments in recent years has not changed the community prevalence of depression overall, but it has reduced the prevalence of more severe depression and suicidal ideations. The findings call for better targeting and more judicious use of antidepressants in cases of more severe depressive episodes which are more likely to respond to such treatments.

    • "and especially psychiatric medications in this period (Mojtabai, 2008). Similar results have been reported from other industrialized countries (Brugha et al., 2004; Jorm, 2014a,b; Jorm and Reavley, 2012; Mojtabai, 2011b; Patten and Beck, 2004). These trends are indeed puzzling and raise questions about the effectiveness of mental health treatments and the public health impact of campaigns aimed at increasing treatment seeking (Jorm, 2014b). "
    [Show abstract] [Hide abstract] ABSTRACT: There has been an increase in the use of mental health services in a number of industrialized countries over the past two decades with little impact on mental health status of the populations. Few studies, however, have examined recent trends in mental health status in the US. Using data from three large general annual population surveys in the US-the National Health Interview Survey, Behavioral Risk Factor Surveillance System, and National Survey on Drug Use and Health-we examined temporal trends in non-specific psychological distress, depressive episodes and mental health treatment seeking over the 2001-2012 period. Prevalence of past-month significant psychological distress and past-year depressive symptoms changed little over time. However, a larger percentage of participants reported poor mental health for ≥15 days or 30 days in the past month in 2011-2012 (8.7% and 5.7%, respectively) than in 2001-2002 (6.6% and 4.6%). A larger percentage of participants in the later period also reported receiving mental health treatments. Possible changes in mental health status may have been missed due to the limited scope of assessments or the small magnitude of changes. Potential reciprocal influences between service use and mental health status could not be investigated because of cross-sectional data. Despite increasing use of mental health treatments in the US in the first decade of this century, there is no evidence of decrease in prevalence of psychological distress or depression. Poor match between need for treatment and actual treatments received in usual care settings may partly explain the findings. Copyright © 2014 Elsevier B.V. All rights reserved.
    No preview · Article · Dec 2014 · Journal of Affective Disorders
  • [Show abstract] [Hide abstract] ABSTRACT: Observational epidemiological studies are increasingly used in pharmaceutical research to evaluate the safety and effectiveness of medicines. Such studies can complement findings from randomized clinical trials by involving larger and more generalizable patient populations by accruing greater durations of follow-up and by representing what happens more typically in the clinical setting. However, the interpretation of exposure effects in observational studies is almost always complicated by non-random exposure allocation, which can result in confounding and potentially lead to misleading conclusions. Confounding occurs when an extraneous factor, related to both the exposure and the outcome of interest, partly or entirely explains the relationship observed between the study exposure and the outcome. Although randomization can eliminate confounding by distributing all such extraneous factors equally across the levels of a given exposure, methods for dealing with confounding in observational studies include a careful choice of study design and the possible use of advanced analytical methods. The aim of this paper is to introduce some of the approaches that can be used to help minimize the impact of confounding in observational research to the reader working in the pharmaceutical industry.
    No preview · Article · Nov 2011 · Pharmaceutical Statistics
  • [Show abstract] [Hide abstract] ABSTRACT: Depression is more frequent in socioeconomically disadvantaged than affluent neighbourhoods, but this association may be due to confounding. This study aimed to determine the independent association between socioeconomic disadvantage and depression. We recruited 21,417 older adults via their general practitioners (GPs) and used the Patient Health Questionnaire (PHQ-9) to assess clinically significant depression (PHQ-9≥10) and major depressive symptoms. We divided the Index of Relative Socioeconomic Disadvantage into quintiles. Other measures included age, gender, place of birth, marital status, physical activity, smoking, alcohol use, height and weight, living arrangements, early life adversity, financial strain, number of medical conditions, and education of treating GPs about depression and self-harm behaviour. After 2 years participants completed the PHQ-9 and reported their use of antidepressants and health services. Depression affected 6% and 10% of participants in the least and the most disadvantaged quintiles. The proportion of participants with major depressive symptoms was 2% and 4%. The adjusted odds of depression and major depression were 1.4 (95% confidence interval, 95%CI=1.1-1.6) and 1.8 (95%CI=1.3-2.5) for the most disadvantaged. The adjusted odds of persistent major depression were 2.4 (95%CI=1.3-4.5) for the most disadvantaged group. There was no association between disadvantage and service use. Antidepressant use was greatest in the most disadvantaged groups. The higher prevalence and persistence of depression amongst disadvantaged older adults cannot be easily explained by confounding. Management of depression in disadvantaged areas may need to extend beyond traditional medical and psychological approaches.
    No preview · Article · Feb 2012 · Journal of Affective Disorders
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