Prevalence, impairment and severity of 12-month DSM-IV major depressive episodes in Te Rau Hinengaro: New Zealand Mental Health Survey 2003/4

Defining and Evaluating Overdiagnosis in Mental Health: A Meta-Research Review

BACKGROUND

Overdiagnosis is thought to be common in some mental disorders, but it has not been defined or examined systematically. Assessing overdiagnosis in mental health requires a consistently applied definition that differentiates overdiagnosis from other problems (e.g., misdiagnosis), as well as methods for quantification.

OBJECTIVES

Our objectives were to (1) describe how the term "overdiagnosis" has been defined explicitly or implicitly in published articles on mental disorders, including usages consistent (overdefinition, overdetection) and inconsistent (misdiagnosis, false-positive test results, overtreatment, overtesting) with accepted definitions of overdiagnosis; and (2) identify examples of attempts to quantify overdiagnosis.

METHOD

We searchedPubMed through January 5, 2019. Articles on mental disorders, excluding neurocognitive disorders, were eligible if they usedthe term "overdiagnosis" in the title, abstract, or text.

RESULTS

We identified 164 eligible articles with 193 total explicit or implicit uses of the term "overdiagnosis." Of 9 articles with an explicit definition, only one provided a definition that was partially consistent with accepted definitions. Of all uses, 11.4% were consistent, and 76.7% were related to misdiagnosis and thus inconsistent. No attempts to quantify the proportion of patients who were overdiagnosed based on overdetection or overdefinition were identified.

CONCLUSIONS

There are few examples of mental health articles that describe overdiagnosis consistent with accepted definitions and no examples of quantifying overdiagnosis based on these definitions. A definition of overdiagnosis based on diagnostic criteria that include people with transient or mild symptoms not amenable to treatment (overdefinition) could be used to quantify the extent of overdiagnosis in mental disorders.

Gender differences in depression in representative national samples: Meta-analyses of diagnoses and symptoms

In 2 meta-analyses on gender differences in depression in nationally representative samples, we advance previous work by including studies of depression diagnoses and symptoms to (a) estimate the magnitude of the gender difference in depression across a wide array of nations and ages; (b) use a developmental perspective to elucidate patterns of gender differences across the life span; and (c) incorporate additional theory-driven moderators (e.g., gender equity). For major depression diagnoses and depression symptoms, respectively, we meta-analyzed data from 65 and 95 articles and their corresponding national data sets, representing data from 1,716,195 and 1,922,064 people in over 90 different nations. Overall, odds ratio (OR) = 1.95, 95% confidence interval (CI) [1.88, 2.03], and d = 0.27 [0.26, 0.29]. Age was the strongest predictor of effect size. The gender difference for diagnoses emerged earlier than previously thought, with OR = 2.37 at age 12. For both meta-analyses, the gender difference peaked in adolescence (OR = 3.02 for ages 13-15, and d = 0.47 for age 16) but then declined and remained stable in adulthood. Cross-national analyses indicated that larger gender differences were found in nations with greater gender equity, for major depression, but not depression symptoms. The gender difference in depression represents a health disparity, especially in adolescence, yet the magnitude of the difference indicates that depression in men should not be overlooked. (PsycINFO Database Record

Gender differences in depression in representative national samples: Meta-analyses of diagnoses and symptoms

In 2 meta-analyses on gender differences in depression in nationally representative samples, we advance previous work by including studies of depression diagnoses and symptoms to (a) estimate the magnitude of the gender difference in depression across a wide array of nations and ages; (b) use a developmental perspective to elucidate patterns of gender differences across the life span; and (c) incorporate additional theory-driven moderators (e.g., gender equity). For major depression diagnoses and depression symptoms, respectively, we meta-analyzed data from 65 and 95 articles and their corresponding national data sets, representing data from 1,716,195 and 1,922,064 people in over 90 different nations. Overall, odds ratio (OR) = 1.95, 95% confidence interval (CI) [1.88, 2.03], and d = 0.27 [0.26, 0.29]. Age was the strongest predictor of effect size. The gender difference for diagnoses emerged earlier than previously thought, with OR = 2.37 at age 12. For both meta-analyses, the gender difference peaked in adolescence (OR = 3.02 for ages 13-15, and d = 0.47 for age 16) but then declined and remained stable in adulthood. Cross-national analyses indicated that larger gender differences were found in nations with greater gender equity, for major depression, but not depression symptoms. The gender difference in depression represents a health disparity, especially in adolescence, yet the magnitude of the difference indicates that depression in men should not be overlooked. (PsycINFO Database Record

Risk factor modifications and depression incidence: a 4-year longitudinal Canadian cohort of the Montreal Catchment Area Study

OBJECTIVE

Few studies have examined the effect of risk factor modifications on depression incidence. This study was to explore psychosocial risk factors for depression and quantify the effect of risk factor modifications on depression incidence in a large-scale, longitudinal population-based study.

METHODS

Data were from the Montreal Longitudinal Catchment Area study (N=2433). Multivariate modified Poisson regression was used to estimate relative risk (RR). Population attributable fractions were also used to estimate the potential impact of risk factor modifications on depression incidence.

RESULTS

The cumulative incidence rate of major depressive disorder at the 2-year follow-up was 4.8%, and 6.6% at the 4-year follow-up. Being a younger adult, female, widowed, separated or divorced, Caucasian, poor, occasional drinker, having a family history of mental health problems, having less education and living in areas with higher unemployment rates and higher proportions of visible minorities, more cultural community centres and community organisations, were consistently associated with the increased risk of incident major depressive disorder. Although only 5.1% of the disease incidence was potentially attributable to occasional drinking (vs abstainers) at the 2-year follow-up, the attribution of occasional drinking doubled at the 4-year follow-up. A 10% reduction in the prevalence of occasional drinking in this population could potentially prevent half of incident cases.

CONCLUSIONS

Modifiable risk factors, both individual and societal, could be the targets for public depression prevention programmes. These programmes should also be gender-specific, as different risk factors have been identified for men and women. Public health preventions at individual levels could focus on the better management of occasional drinking, as it explained around 5%~10% of incident major depressive disorders. Neighbourhood characteristics could also be the target for public prevention programmes. However, this could be very challenging. A cost-effectiveness analysis of a variety of prevention efforts is warranted.

The projected effect of risk factor reduction on major depression incidence: a 16-year longitudinal Canadian cohort of the National Population Health Survey

BACKGROUND

Few studies have examined the effect of risk factor modification on depression incidence. This study estimated the effect of risk factor modification on depression incidence.

METHODS

Data analyzed were from the Canadian National Population Health Survey (NPHS) - a longitudinal population-based cohort study. The study followed-up a national cohort sample over a 16-year period from 1994 to 2010. Multivariate modified Poisson regression was used to estimate relative risk.

RESULTS

The cumulative incidence rate of depression during the 16-year follow-up was 12.07%. Being younger adult, female, Caucasian, poor, occasional/abstainer/former drinker, regular smoker, and having chronic disease were significantly associated with an increased risk of developing depression. About 40% of depression incidence (850,000 cases) was potentially attributable to modifiable risk factors (poor income, smoking, and having a chronic disease). A 10% reduction in the prevalence of these modifiable risk factors could potentially prevent about 165,000 cases of depression.

LIMITATIONS

The calculation of PAFs assumes that there is a causal relationship between a risk factor and depression. However, major depression has multiple causes. The potential effect of risk factor modification on depression incidence may vary by the profile of risk factors assessed in a particular study. Several potentially important risk factors were not included in this study.

CONCLUSION

Public health campaigns targeted at significant modifiable risk factors could have a profound effect on future depression incidence. Prevention trials are needed to directly evaluate the effect of single and/or multiple risk factors modification on depression incidence.

Depression in primary care: current and future challenges

OBJECTIVES

To describe the current state of knowledge about detection and treatment of major depressive disorder (MDD) by family physicians (FPs), and to identify gaps in practice and current and future challenges.

METHODS

We reviewed the recent literature on MDD (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, or International Classification of Diseases, Revision 10) in primary care, with an emphasis on systematic reviews and meta-analyses addressing prevalence, the impact of an aging population and of chronic disease on MDD rates in primary care, detection and treatment rates by FPs, adequacy of treatment, and interventions that could improve recognition and treatment.

RESULTS

About 10% of primary care patients are likely to meet criteria for MDD. The number of cases will increase as the baby boomer cohort ages and as the prevalence of chronic disease increases. The bidirectional relation between MDD and chronic disease is now firmly established. Detection and treatment rates in primary care remain low. Treatment quality is frequently inadequate in terms of follow-up and monitoring. Formal case management and collaborative care interventions are likely to provide some benefits.

CONCLUSIONS

Low detection rates and low treatment rates need to be addressed. Planned reassessment may improve detection rates when the FP is uncertain whether MDD is present, but further research is needed to determine why FPs frequently do not initiate treatment, even when MDD is detected. A caring, attentive FP who monitors depressed patients is likely to have considerable placebo effect. Greater focus on integrated, concurrent treatment for MDD and chronic physical diseases in the middle-aged and elderly is also required.

Gender differences in the disability (functional limitations) associated with cardiovascular disease: a general population study

BACKGROUND

Although it is widely believed that women with heart disease have poorer adjustment than men, the term 'adjustment' has typically been narrowly defined as depression. Gender differences in adjustment more broadly defined to encompass functional limitations in addition to depression have seldom been investigated, especially in general population samples with an adequate number of women.

METHODS

A nationally representative general population survey of 7434 New Zealanders (618 with cardiovascular disease: CVD; 335 women, 283 men). DSM-IV mental disorders were measured with the Composite International Diagnostic Interview (CIDI 3.0). Health-related disability (functional limitations) was measured using the World Mental Health-World Health Organization Disability Adjustment Schedule (WHODAS-II). CVD was ascertained by self-report of a physician's diagnosis of heart disease, heart attack, or stroke.

RESULTS

In age-adjusted analyses, cardiovascular disease was associated with significant functional limitations in a range of disability domains in both men and women, but there were no gender differences in the degree of disability.

CONCLUSION

In this general population sample, men and women with CVD reported similar degrees of disability, despite women's higher prevalence of depression. This does not support earlier conclusions that women with heart disease cope less well than men.