Minor change in the diagnostic threshold leads into major alteration in the prevalence estimate of depression

Global Burden Disease Estimates for Major Depressive Disorders (MDD): A review of diagnostic instruments used in studies of prevalence

Global Burden of Disease (GBD) estimates have significant policy implications nationally and internationally. Disease burden metrics, particularly for depression, have played a critical role in raising governmental awareness of mental health and in calculating the economic cost of depression. Recently, the World Health Organization ranked depression as the single largest contributor to global disability. The main aim of this paper was to assess the basis upon which GBD prevalence estimates for major depressive disorder (MDD) were made. We identify the instruments used in the 2019 GBD estimates and provide a descriptive assessment of the five most frequently used instruments. The majority of country studies, 356/566 (62.9%), used general mental health screeners or structured/semi-structured interview guides, 98/566 (17.3%) of the studies used dedicated depression screeners, and 112 (19.8%) used other tools for assessing depression. Thus, most of the studies used instruments that were not designed to make a diagnosis of depression or assess depression severity. Our results are congruent with and extend previous research that has identified critical flaws in the data underpinning the GBD estimates for MDD. Despite the widespread promotion of these prevalence estimates, caution is needed before using them to inform public policy and mental health interventions. This is particularly important in lower-income countries where resources are scarce.

Prevalence, correlates and misperception of depression symptoms in the United States, NHANES 2015-2018

PURPOSE

To update the prevalence of depression in the US and identify whether misperception exists in depression assessed by self-report versus validated tools administered by trained professionals.

METHODS

We extracted data on sociodemographic characteristics, lifestyle factors, medical conditions, depressive symptoms, and self-reported depressive feeling from National Health and Nutrition Examination Survey (NHANES) study 2015-2018. We calculated the weighted prevalence and 95% CI of depressive symptoms assessed by a validated tool PHQ-9 (score≥10) and self-reported depression respectively. Then, we performed multivariable logistic regressions to identify their sociodemographic and lifestyle correlates. Finally, we calculated the agreement between PHQ-9 assessed depressive symptoms and self-reported depressive feeling to examine possible misperception.

RESULTS

The present analysis included a total of 10,257 adults (Weighted N = 215,964,374) aged 20 years and older. Prevalence of depressive symptoms (PHQ-9 score ≥10) were 8.0% from 2015 to 2018 in the US. 19.7% and 11.3% adults reported feeling depressed at least once a month and at least once a week, respectively. Depressive experience was largely misperceived in the US (Kappa agreement = 50.98%, Cohen's Kappa = 0.16, p < 0.001). Particularly, an estimated 1.1 million US adults had depressive symptoms but never felt being depressed. Several consistent demographic and behavioral correlates were identified across the two measures, namely: age, sex, race/ethnicity, poverty and sitting time.

CONCLUSIONS

A high prevalence of depression was found, and misperception of depression exists among the US adult population. Our findings highlight an urgent need for health professionals to reduce the burden of depression with considering patients' socioeconomic status and lifestyle factors.

Time trends in depression prevalence and health-related correlates: results from population-based surveys in Germany 1997-1999 vs. 2009-2012

BACKGROUND

Although an "epidemic" of depression is frequently claimed, empirical evidence is inconsistent, depending on country, study design and depression assessment. Little is known about changes in depression over time in Germany, although health insurance companies report frequency increases. Here we examined time trends in depression prevalence, severity and health-related correlates in the general population.

METHODS

Data were obtained from the mental health module of the "German Health Interview and Examination Survey for Adults" (2009-2012, n = 3265) and the mental health supplement of the "German National Health Interview and Examination Survey 1998" (1997-1999, n = 4176), excluding respondents older than 65. 12-month major depressive disorder (MDD), severity and symptoms were assessed based on the WHO Composite International Diagnostic Interview. Health-related quality of life (SF-36), self-reported sick days or days with limitations in normal daily life activities were examined, too. Calculations were carried out population-weighted. Additional age-standardized analyses were conducted to account for demographic changes.

RESULTS

Overall, MDD 12-month prevalence remained stable at 7.4%. Women showed a shifted age distribution with increased prevalence at younger ages, and increasing MDD severity. Time trends in health-related correlates occurred both in participants with and without MDD. Mental health disability increased over time, particularly among men with MDD, reflected by the mental component score of the SF-36 and days with activity limitation due to mental health problems. Demographic changes had a marginal impact on the time trends.

CONCLUSIONS

In contrast to the ongoing international debate regarding increased depression rates in western countries, we found no increase in overall MDD prevalence in Germany over a long period. In conclusion, increased depression frequencies in national health insurance data and growing health care costs associated with depression are not attributable to overall prevalence changes at a population level. However, shifted age distribution and increased severity among women may reflect a rising depression risk within this specific subgroup, and changes in health-related correlates indicate a growing mental health care need for depression, particularly among men.

Criteria Definitions and Network Relations: The Importance of Criterion Thresholds

Across various structured diagnostic instruments, the criteria used to diagnose alcohol use disorder (AUD) are not assessed consistently. For example, different instruments often pose questions that reflect different thresholds of the underlying symptoms. We consider the criteria for craving and the inability to cut down or stop drinking to demonstrate the influence of using different thresholds for a positive symptom endorsement with respect to the estimated edges of a symptom network. Results indicate that the utilization of these differing thresholds leads to significant differences in edge weights. Generally, higher thresholds relate more strongly to lower prevalence rate criteria, and the reverse for lower thresholds. These findings have implications for reproducibility of effects in symptom networks and their generalization across studies.

The 5-HT1A receptor in Major Depressive Disorder

Major Depressive Disorder (MDD) is a highly prevalent psychiatric diagnosis that is associated with a high degree of morbidity and mortality. This debilitating disorder is currently one of the leading causes of disability nationwide and is predicted to be the leading cause of disease burden by the year 2030. A large body of previous research has theorized that serotonergic dysfunction, specifically of the serotonin (5-HT) 1A receptor, plays a key role in the development of MDD. The purpose of this review is to describe the evolution of our current understanding of the serotonin 1A (5-HT1A) receptor and its role in the pathophysiology MDD through the discussion of animal, post-mortem, positron emission tomography (PET), pharmacologic and genetic studies.

Current major depressive syndrome measured with the Patient Health Questionnaire-9 (PHQ-9) and the Composite International Diagnostic Interview (CIDI): results from a cross-sectional population-based study of adults in Germany

BACKGROUND

Prevalence estimates for depression vary considerably by the type of assessment instrument, and there is limited information on their overlap in population-based samples. Our aim was to compare the Patient Health Questionnaire-9 (PHQ-9) with the Composite International Diagnostic Interview (CIDI) as measures for current major depressive syndrome (MDS) in a large population-based sample.

METHODS

Data derived from the mental health module of the nationwide cross-sectional German Health Interview and Examination Survey for Adults (DEGS1-MH) (n = 4483; age 18-79 years). MDS in the past two weeks was assessed (a) using the PHQ-9 diagnostic algorithm (PHQ-MDS) and (b) based on CIDI information about the latest symptom occurrence (recency) (CIDI-MDS). Prevalences, overall concordance and percentages of overlap of both MDS measures were determined. Prevalences of affirmed PHQ-9 depression symptoms and the mean and median PHQ-9 sum scores were analyzed per measure.

RESULTS

Prevalence of current MDS was 2.7% (95% CI: 2.0-3.6) for PHQ-MDS and 3.9% (95% CI: 3.1-5.0) for CIDI-MDS. The overall agreement between both measures was moderate (kappa: 0.43). Of all the participants, 1.5% (95% CI: 1.0-2.2) were classified as MDS cases by both measures, with 54.5% (95% CI: 42.7-65.9) of PHQ-MDS cases and 37.9% (95% CI: 27.8-49.1) of CIDI-MDS cases also being classified as MDS by the respective other MDS measure. However, 94.8% (95% CI: 93.6-95.8) of the participants were classified as non-MDS by both measures, with 97.5% (95% CI: 96.6-98.1) of non-PHQ-MDS and 98.7% (95% CI: 98.2-99.1) of non-CIDI-MDS being classified as non-MDS by the respective other MDS measure. The mean and median PHQ-9 sum score was higher in those with PHQ-MDS than in those with CIDI-MDS.

CONCLUSIONS

Both measures have a high level of agreement for ruling out current MDS, but the overlap in their classification of cases is moderate. Our results indicate that they cannot be interpreted as equal measures of the same construct, suggesting limited comparability of their prevalence estimates. However, further exploration of algorithms and correlates and a proper labeling of measures in epidemiological studies are required.

Self-reported depression is increasing among socio-economically disadvantaged adolescents - repeated cross-sectional surveys from Finland from 2000 to 2011

Background

Adolescent depression is more common in lower socio-economic groups. Whether this pattern has changed over time, is not known.

We examined the prevalence of self-reported depression and its changes in socio-economic groups from 2000 to 2011 among Finnish adolescents.

Methods

Data were based on classroom surveys every second year from 2000–2001 to 2010–2011 using nationwide samples of 14–16-year old Finns (n = 618,084). Data were collected using self-administered questionnaires including questions on health, health behaviours, and school experiences. Depression was measured with a Finnish modification of the 13-item Beck Depression Inventory, and divided into no, mild, moderate and severe depression. The association between depression and the social background (parents’ education and employment) over time was studied using a multinomial regression analysis.

Results

The prevalence of self-reported severe depression slightly increased from 2000–2001 to 2010–2011 in girls. In boys a slight increase was observed when adjusting for background variables. The differences in the prevalence of depression between the social background groups persisted over the entire study period. In both sexes, severe depression nearly doubled among those adolescents whose parents were unemployed and had a low education level; among boys, the prevalence was 6.5% in 2000–2001 and 12.8% in 2010–2011, and among girls 6.4% and 11.4% respectively.

Conclusion

The largest increases in prevalence of severe depression are seen among socio-economically disadvantaged adolescents. This suggests that inequalities in mental health may become an increasing concern.

Diagnosed, identified, current and complete depression among patients attending primary care in southern Catalonia: different aspects of the same concept

The aims of this study were to explore the prevalence and the conceptualizations of depression detected by the healthcare system, identified by the patient or classified/identified in the validated Goldberg's questionnaire in a community. We conducted a cross-sectional evaluation of 317 patients. The different types of depression diagnosed, identified, current or total were stratified by age and gender groups. The difference in the conceptualization of depression from the medical or ordinary people point of view indicate that depression care requires the understanding of the lifestyle, beliefs, attitudes, family and social networks of the people the physicians and nurses care for.

What characterizes late-life depression?

This article analyzes late-life depression, looking carefully at what defines a person as elderly, the incidence of late-life depression, complications and differences in symptoms between young and old patients with depression, subsyndromal depression, bipolar depression in the elderly, the relationship between grief and depression, along with sleep disturbances and suicidal ideation.

Prevalence and comorbidities of adolescent depression in Germany. An analysis of Health Insurance Data

OBJECTIVE

Data on the prevalence of depressive disorders in adolescents are scarce. We aimed to examine the administrative prevalence of depressive disorders and related comorbidities in German adolescents. A second objective of was to assess potential regional (East vs. West Germany) differences in depression prevalence.

METHOD

Data of a statutory health insurance company were analysed and outpatients from 12 to 18 years of age with diagnosed depression during a one-year-period (2009) were identified.

RESULTS

The population at risk consisted of 140,563 adolescents. Of these, 4,295 (41.2% male; mean age: 15.5 years) had a diagnosis of depression. This equates to a prevalence of 3.1% (females: 3.7%, males: 2.5%). There were no significant differences between East and West Germany. Of all adolescents with depression, 62.5% had at least one comorbid psychiatric diagnosis, with anxiety and emotional disorders (23.7%), somatoform disorders (16.8%), hyperkinetic disorders (16.2%) and posttraumatic stress disorder (10.0%) being most frequently diagnosed.

CONCLUSIONS

The depression prevalence in this sample was lower than that in studies of clinical samples. There was a marked prevalence of psychiatric comorbidities, especially of internalizing disorders. In adolescents, the risk of depression seems to be comparable in both East and West Germany.

The 2-week duration criterion and severity and course of early childhood depression: implications for nosology

BACKGROUND

Although validity for DSM-IV MDD symptom criteria in preschoolers has been demonstrated, whether the 2-week duration criterion is an appropriate threshold of clinical significance at this age remains unclear. The current study aimed to begin addressing this question.

METHOD

Three hundred and six preschoolers were recruited from community sites and followed longitudinally for 2 years. A subsample including healthy preschoolers (N=77) and those with MDD (N=74) were examined. The MDD group was further divided based upon meeting (DSM, N=24) or failing to meet (<DSM, N=50) the DSM-IV 2-week duration criterion. Groups were compared on parent and teacher report measures of symptom severity and functional impairment at baseline and 2-year follow-up.

LIMITATIONS

A larger sample of depressed preschoolers and refined measures of duration are needed to replicate the current study.

RESULTS

Preschoolers with MDD differed significantly from controls on the majority of measures examined regardless of duration status and time of assessment. Further, the DSM group significantly differed from the<DSM group at baseline on measures of MDD symptom severity and impairment. No differences in the risk of a MDD diagnosis at follow-up were found on the basis of duration group status.

CONCLUSIONS

DSM-IV duration criterion failed to capture all clinically affected preschoolers at baseline or confer greater predictive validity for a depression diagnosis 2 years later. Findings suggest that preschoolers meeting all DSM-IV MDD criteria except for episode duration exhibit a clinically significant form of depression and experience a 2-year MDD outcome similar to those meeting full criterion.