Subthreshold depression as a risk indicator for major depressive disorder: a systematic review of prospective studies

Prevalence of mental disorders based on general population surveys

OBJECTIVE

In the last two decades, a multitude of investigations into the frequency of mental disorders in the population have emerged, making it difficult to keep track of recent findings and tasks. Building on a historical review, the present study provides a comprehensive overview of knowledge about the prevalence of mental disorders.

METHOD

The review is based on current national surveys with comparable methodology. Study selection, based on a consecutive literature search through August 2005, led to the inclusion of Australian, German, Dutch and US-American (NCS; NCS-R) surveys of mental disorders in the general population.

RESULTS

A considerable proportion of the population is found to have a mental disorder. The most frequent disorders within the preceding 12 months are mood disorders (6.6-11.9%) and anxiety disorders (5.6-18.1%). Substance disorders (3.8-11.3%) and somatoform disorders (11.0%) are also very frequent. The prevalence rates presented in each survey are dependent on the specific disorders included and the classification system underlying them. Important risk factors are being female, being unmarried, being unemployed and having a low social status.

CONCLUSIONS

Knowledge about mental disorders in the general population can contribute to bringing about considerable improvement in the treatment of mental disorders. In addition to available knowledge, however, there is a continued need to address existing challenges from both a methodological and content-related perspective, e.g. the lack of or inadequate inclusion of specific disorders, the lack of prevalence rates of mental disorders in childhood and adolescence, and the as yet only rare inclusion of personality disorders.

Psychological treatments of subthreshold depression: a meta-analytic review

OBJECTIVE

Subthreshold depression has a considerable impact on the quality of life and carries a high risk of developing major depressive disorder. Psychological treatments for subthreshold depression may be able to reduce depressive symptomatology and prevent the onset of major depression.

METHOD

We conducted a meta-analysis of randomized controlled studies examining the effects of psychological treatments for subthreshold depression. We examined the effects on depressive symptoms and the preventive effects on the incidence of major depression.

RESULTS

Seven high-quality studies with a total of 700 subjects were included. The mean effect size at post-test was 0.42 (95% CI: 0.23-0.60), with very low heterogeneity. The relative risk of developing a major depressive disorder in subjects who received the intervention was 0.70 (95% CI: 0.47-1.03; P = 0.07).

CONCLUSION

Psychological treatments have significant effects on subthreshold depression. Furthermore, these interventions may prevent the onset of major depression.

Web-based tools can be used reliably to detect patients with major depressive disorder and subsyndromal depressive symptoms

BACKGROUND

Although depression has been regarded as a major public health problem, many individuals with depression still remain undetected or untreated. Despite the potential for Internet-based tools to greatly improve the success rate of screening for depression, their reliability and validity has not been well studied. Therefore the aim of this study was to evaluate the test-retest reliability and criterion validity of a Web-based system, the Internet-based Self-assessment Program for Depression (ISP-D).

METHODS

The ISP-D to screen for major depressive disorder (MDD), minor depressive disorder (MinD), and subsyndromal depressive symptoms (SSD) was developed in traditional Chinese. Volunteers, 18 years and older, were recruited via the Internet and then assessed twice on the online ISP-D system to investigate the test-retest reliability of the test. They were subsequently prompted to schedule face-to-face interviews. The interviews were performed by the research psychiatrists using the Mini-International Neuropsychiatric Interview and the diagnoses made according to DSM-IV diagnostic criteria were used for the statistics of criterion validity. Kappa (kappa) values were calculated to assess test-retest reliability.

RESULTS

A total of 579 volunteer subjects were administered the test. Most of the subjects were young (mean age: 26.2 +/- 6.6 years), female (77.7%), single (81.6%), and well educated (61.9% college or higher). The distributions of MDD, MinD, SSD and no depression specified were 30.9%, 7.4%, 15.2%, and 46.5%, respectively. The mean time to complete the ISP-D was 8.89 +/- 6.77 min. One hundred and eighty-four of the respondents completed the retest (response rate: 31.8%). Our analysis revealed that the 2-week test-retest reliability for ISP-D was excellent (weighted kappa = 0.801). Fifty-five participants completed the face-to-face interview for the validity study. The sensitivity, specificity, positive, and negative predictive values for major depressive disorder were 81.8% and 72.7%, 66.7%, and 85.7% respectively. The overall accuracy was 76.4%.

CONCLUSION

The evidence indicates the ISP-D is a reliable and valid online tool for assessing depression. Further studies should test the ISP-D in clinical settings to increase its applications in clinical environments with different populations and in a larger sample size.

The iron status, clinical symptom and anthropometry between normal and anemic groups of middle school girls

This research analyzed the iron status, clinical symptoms and physical characteristics between normal and anemic group of middle school girls in the Ulsan metropolitan area. It was carried out with 237 subjects (normal 190, anemic subject 47). They were evaluated with a questionnaire and measurement of hematological indices. BMI (kg/m²) of the two groups were 19.54 ± 2.44 (normal girls) and 19.22 ± 2.27 (anemic girls). The hemoglobin concentration of the anemic girls were 10.84 ± 1.17g/dl and the serum iron of the anemic girls represent 35.15 ± 27.47 µg/100 ml. The TIBC (Total Iron Binding Capacity) of the anemic girls showed significantly high to 449.30 ± 64.87 µg/100 ml. The serum ferritin of the anemic girls was 20.53 ± 42.29 µg/ℓ, it represented significantly low. The symptom of 'pale face' of the anemic girls were higher than the normal girls. Hemoglobin and serum iron were negatively correlated with 'pale face'. The TIBC was negatively correlated with 'Get a cold easily'. The duration and amount of menstruation were correlated with iron status. This research is to be utilized as basic data for dietary support and nutritional education to improve their iron status.

Economic costs of minor depression: a population-based study

OBJECTIVE

Although the clinical relevance of minor depression has been demonstrated in many studies, the economic costs are not well explored. In this study, we examine the economic costs of minor depression.

METHOD

In a large-scale, population-based study in the Netherlands (n = 5504) the costs of minor depression were compared with the costs of major depression and dysthymia. Excess costs, i.e. the costs of a disorder over and above the costs attributable to other illnesses, were estimated with help of regression analysis. The direct medical costs, the direct non-medical costs and the indirect non-medical costs were calculated. The year 2003 was used as the reference year.

RESULTS

The annual per capita excess costs of minor depression were US$ 2141 (95% CI = 753-3529) higher than the base rate costs of US$ 1023, while the costs of major depression were US$ 3313 (95% CI = 1234-5390) higher than the base rate. The costs of minor depression per 1 million inhabitants were 160 million dollars per year, which is somewhat less than the costs of major depression (192 million dollars per year).

CONCLUSION

The economic costs associated with minor depression are considerable and approach those of major depression.

Dimensionality and the category of major depressive episode

Major depressive episode (MDE) is a chronic disease typified by episodes that remit and recur. It is a major contributor to the burden of disease. The diagnosis of a disorder is an expert opinion that the disorder is present. The nine symptoms of MDE exist on dimensions of greater or lesser intensity, persistence over time, change in usual state, distress and impairment. It is the clinician's task to judge whether the elicited symptoms warrant the diagnosis. The surprise is that trained clinicians can do this reliably and that diagnostic interviews and questionnaires can emulate this process. The distribution of symptoms in community surveys is exponential, with no obvious discontinuity at the diagnostic threshold. Taxometric and primary care studies confirm this. The number of symptoms predicts severity, comorbidity, family history, disability, help seeking and treatment recommendations. The latent structure of mental disorders places MDE in the distress misery cluster. Measures of well-being, distress, disability and neuroticism correlate with the number of symptoms but the relation is not perfect. The Patient Health Questionnaire is derived from the diagnostic criteria and does not suffer this limitation. The introduction of measures like this would acknowledge dimensionality, would facilitate recognition, guide treatment, and be acceptable to consumers, providers and funders.

Predictors of future depression in early and late adolescence

BACKGROUND

This study examined whether the possibility to predict future DSM-IV depressive disorder can be increased with recurrent screening for depression in community adolescents, compared to single screening in early or in late adolescence. In addition, it examined which depressive symptoms in early and late adolescence predicted future depressive disorder most accurately.

METHODS

Participants from an ongoing longitudinal cohort study were assessed when they were aged between 10 and 15 (early adolescence), and between 14 and 19 (late adolescence), and were followed until they were 20-25 (young adulthood). The Child Behavior Checklist (CBCL) and Youth Self-Report (YSR) were used to screen for depression in early and late adolescence, and CIDI/DSM-IV diagnoses of depressive disorder were used as the outcome measure during follow-up.

RESULTS

Recurrent screening only slightly improved the prediction of future depression, and cognitive and physical symptoms in late adolescence predicted future depression accurately in boys. Sleeping problems in early adolescence predicted future depression in girls.

LIMITATIONS

The main limitation was the retrospective recall of the age of onset of a depressive disorder.

CONCLUSIONS

Recurrent screening for depression did not predict future depressive disorder better than single screening in late adolescence. However, depressive symptoms like sleeping problems predicted future depression quite accurately in adolescent boys and girls. This indicates that it may be useful to screen adolescents for the presence of such symptoms, for instance in school settings, to predict which adolescents are at risk to develop DSM-IV depressive disorder in early adulthood.

Seven-year outcome of depression in primary and psychiatric outpatient care: results of the TADEP (Tampere Depression) II Study

The objective of this article was to determine a 7-year naturalistic progression of depression as well as a number of potential prognostic factors among Finnish primary care and psychiatric care patients. Depression-screened patients from primary care and psychiatric care, aged 18-64, were interviewed in 1991-92 with the Present State Examination (PSE) as the diagnostic instrument. The patients were re-contacted in 1998-99, and their depression at final assessment (FinalA) and during the follow-up period (F-up) was assessed by telephone interview using the Composite International Diagnostic Interview--Short Form (CIDI-SF). 250 primary care (58.1%) and 170 (40.2%) psychiatric care patients were successfully followed. Of the primary care patients with severe depression at baseline, 42.4% had had depression during F-up and 21.2% had depression at FinalA. For the patients with mild depression at baseline, the corresponding figures were nearly the same, but for the patients with depressive symptoms clearly lower. Of the psychiatric care patients with severe depression at baseline, 61.0% had had depression during F-up and 26.2% had depression at FinalA. As with primary care patients, the corresponding figures were nearly the same for mild depression at baseline but clearly lower for depressive symptoms. Experienced lifetime mood elevation was associated with having depression during F-up in both primary care and psychiatric care patients. High Depression Scale (DEPS) score at baseline was associated with having depression at FinalA in primary care patients, but in psychiatric care patients, it was the high Hamilton Rating Scale for depression (HAM-D) and drinking problems. Severe depression and mild depression are predictive for subsequent depression at both levels of care. The long-term prognosis for depression is better in primary care. DEPS and HAM-D are useful, prognostic instruments.

Cost-utility of selective serotonin reuptake inhibitors for depression in primary care in Catalonia

OBJECTIVE

To determine the cost-utility of selective serotonin reuptake inhibitors (SSRIs) for treating depressive disorders prescribed in primary care (PC).

METHOD

A total of 301 participants beginning antidepressant treatment with an SSRI were enrolled in a prospective 6-month follow-up naturalistic study. Incremental cost-utility ratios (ICUR) were obtained for several comparisons among different SSRIs. To address uncertainty in the ICUR's sampling distribution, non-parametric bootstrapping was carried out.

RESULTS

Taking into account adjusted total costs and incremental quality of life gained, fluoxetine dominated paroxetine and citalopram with 63.4% and 79.3% of the bootstrap replications in the dominance quadrant, respectively. Additionally, fluoxetine was cost-effective over sertraline with 83.4% of the bootstrap replications below the threshold of 33,936 US$/quality-adjusted life year (30,000 euro/QALY).

CONCLUSION

Fluoxetine seems to be a better cost-utility SSRI option for treating depressive disorders in PC.

Predicting the onset of major depressive disorder and dysthymia in older adults with subthreshold depression: a community based study

BACKGROUND

It is well-established that the incidence of major depressive disorder is increased in subjects with subthreshold depression. A new research area focuses on the possibilities of preventing the onset of major depressive disorders in subjects with subthreshold depression. An important research question for this research area is which subjects with subthreshold depression will develop a full-blown depressive disorder and which will not.

METHODS

We selected 154 older subjects with subthreshold depression (CES-D>16) but no DSM mood disorder from a longitudinal study among a large population based cohort aged between 55 and 85 years in The Netherlands. Of these subjects, 31 (20.1%) developed a mood disorder (major depression and/or dysthymia) at three-year or six-year follow-up. We examined risk factors and individual symptoms of mood disorder as predictors of onset of mood disorder.

RESULTS

Two variables were found to be significant predictors in both bivariate and multivariate analyses: eating problems and sleep problems. The incidence of mood disorders differed strongly for different subpopulations, varying from 9% (for those not having any of the two risk factors) to 57% (for those having both risk factors).

CONCLUSIONS

It appears to be possible to predict to a certain degree whether a subject with subthreshold depression will develop a mood disorder during the following years.

Posttraumatic stress disorder Part III: health effects of interpersonal violence among women

TOPIC

The aim of this three-part series is to examine the sufficiency of the posttraumatic stress (PTSD) diagnostic construct to capture the full spectrum of human responses to psychological trauma. Part I (Lasiuk & Hegadoren, 2006a) reviewed the conceptual history of PTSD from the nineteenth century to its inclusion in the third edition of the Diagnostic and Statistical Manual of Mental Disorders (American Psychiatric Association, 1980), while Part II (Lasiuk & Hegadoren, 2006b) described subsequent refinements to the original PTSD diagnostic criteria and highlighted subsequent controversies.

PURPOSE

This paper focuses on interpersonal violence (sexual, physical, and emotional abuse/assault) and its sequelae in women. We argue in support of Judith Herman's (1992) conceptualization of the human trauma response as a spectrum, anchored at one end by an acute stress reaction that resolves on its own without treatment, and on the other by "complex" PTSD, with "classic" or "simple" PTSD somewhere between the two.

SOURCES OF INFORMATION

he existing theoretical, clinical and research literatures related to humans responses to trauma.

CONCLUSION

The paper concludes with a call for the need to increase a gendered perspective in all aspects of trauma research and clinical service delivery.

Classification and treatment of sub-threshold depression

PURPOSE OF REVIEW

The purpose of this review is to evaluate the recent literature on depressive spectrum disorders.

RECENT FINDINGS

Research into so-called 'minor' forms of depression has moved beyond efforts justifying these entities and describing their components to an exploration of the impact of depressive spectrum disorders on health, quality of life, and as a predisposing factor for major depressive disorder. As with major depression, pharmacological and psychosocial interventions may be useful treatments. Researchers have begun to examine the nature of depressive spectrum disorders in specific populations, such as the elderly and the medically ill.

SUMMARY

Sub-threshold forms of depression are becoming a focus of research at a time when quality of life and prevention of serious mental illness are being recognized as important public health concerns. Individuals with depressive spectrum disorders are at an increased risk of developing major depressive disorder and are more likely to have a history of episodes of depression. The challenges confronting psychiatric researchers include developing a consensus about diagnosis of depressive spectrum disorders and ways to measure their severity, and increasing public recognition of the impact of the entire spectrum of depression in order to facilitate the discovery of appropriate treatments.

Minor depression as a predictor of the first onset of major depressive disorder over a 15-year follow-up

OBJECTIVE

To study the relationship of minor depression to first onset of major depressive disorder (MDD) among 1634 individuals over a 15-year follow-up using the Baltimore Epidemiologic Catchment Area cohort.

METHOD

Logistic regression analyses were conducted with minor depression alone and also adjusting for anxiety, sociodemographic, and medical variables, with MDD as the outcome variable. Also, among those with minor depression, depressive symptom categories were studied with both logistic regression and population attributable risk (PAR) to determine if they predicted MDD.

RESULTS

Individuals with a history of minor depression had an odds ratio of more than 5 of having a first lifetime episode of MDD (adjusted OR: 5.37, 95% CI: 2.87, 10.06). Suicidal ideation, appetite/weight issues, and sleep difficulty had the highest PARs.

CONCLUSION

Minor depression strongly predicts MDD. Clinical and public health interventions for individuals with minor depression can potentially impact the pathway leading to MDD.

Male elderly subthreshold depression patients have smaller volume of medial part of prefrontal cortex and precentral gyrus compared with age-matched normal subjects: a voxel-based morphometry

BACKGROUND

The brain morphological changes in subthreshold depression (sD) have not been clarified. We examined the structural difference in regional gray matter volume between community-dwelling elderly subjects with sD and age-matched nondepressed normal subjects by voxel-based morphometry (VBM) based on magnetic resonance imaging (MRI).

METHODS

Thirty-four community-dwelling elderly subjects with sD and 109 age-matched nondepressed normal subjects were studied by MRI. We defined subjects with sD as those who showed a Geriatric Depression Scale score of 15 or higher and a Mini Mental State Examination score of 22 or higher, and do not fulfill the criteria of major depressive disorder (MDD) in the Diagnostic and Statistical Manual for Mental Disorders IV. We collected brain magnetic resonance images of 34 subjects with sD and 109 age-matched normal subjects, and analyzed the difference in regional gray matter volume between these two groups by VBM.

RESULTS

Male subjects with sD had significantly smaller volumes of the medial part of the bilateral frontal lobes and the right precentral gyrus than normal male subjects.

LIMITATIONS

We have not clarified the discrepancy in the results of gender difference.

CONCLUSIONS

Our study revealed that even community-dwelling elderly male subjects with sD show bilateral prefrontal gray matter volume reduction, which was reported to be observed in elderly patients with MDD, although there is no significant volume reduction in the hippocampus, which was also reported to be observed in MDD. Our study may contribute to clarifying the mechanism underlying brain pathological changes in sD.

Predicting the onset of major depression in subjects with subthreshold depression in primary care: a prospective study

OBJECTIVE

That subjects with subthreshold depression have an increased probability of developing major depression has been confirmed by many studies. However, the factors which may predict the onset of major depression have yet to be fully examined.

METHOD

We examined the control group of a randomized trial in primary care patients with subthreshold depression (N = 109), of whom 20 had developed major depression 1 year later. Using the vulnerability-stress theory, we examined which factors predicted the onset of major depression.

RESULTS

In both univariate and multivariate analyses, family history and chronic illnesses predicted the onset of major depression.

CONCLUSION

It is possible to predict to a certain degree whether a subject with subthreshold depression will develop major depression within a year.