Subtypes of depression in a nationally representative sample

Cross-measure equivalence and communicability in the assessment of depression: a focus on factor-based scales

All measures of depression yield a global summary scale indicating the severity of depressive symptoms, implicitly conceptualized as a homogeneous construct. However, depression is a heterogeneous construct, with different presentations, subtypes, correlates, and responses to interventions. In response, the National Institute of Mental Health (NIMH) has suggested changes in the way depression is assessed, moving the focus to specific factors, such as cognitive, somatic, or affective symptoms. Still, there is little factor overlap between measures, and shared factors are weighted differently. To help fulfill NIMH's strategic plan, this study used canonical correlation analysis (CCA) to explore shared latent variables and redundancy across the measures. It also analyzed the psychometric properties of factor-based subscales in the Beck Depression Inventory-2nd edition (BDI-II), Center for Epidemiologic Studies Depression scale (CES-D), Inventory for Depression and Anxiety Symptoms (IDAS), and Inventory of Depressive Symptomatology (IDS). Using a diverse sample of 218 students who reported at least mild depressive symptoms, this study found that the IDAS was best aligned with NIMH's strategic plan; it has complete DSM-IV/DSM-5 symptom coverage and content-valid, psychometrically sound subscales. The BDI-II, CES-D, and IDS did not have consistent subscales, nor had incomplete or incongruent coverage of DSM criteria. Furthermore, CCA revealed low redundancy across measures (23% to 41% shared variance). These results suggest that different measures of depression do not measure the same construct. As a partial solution, empirical conversion tables were provided for researchers and clinicians to empirically compare total scores from different measures.

Dimensions in major depressive disorder and their relevance for treatment outcome

BACKGROUND

Major depressive disorder (MDD) is a heterogeneous disease. More homogeneous psycho(patho)logical dimensions would facilitate MDD research as well as clinical practice. The first aim of this study was to find potential dimensions within a broad psychopathological assessment in depressed patients. Second, we aimed at examining how these dimensions predicted course in MDD.

METHODS

Ten psychopathological variables were assessed in 75 MDD inpatients. Factor and regression analyses assessed putative relations between psychopathological factors and depression severity and outcome after 8 weeks of treatment.

RESULTS

A 3-factor model (eigenvalue: 54.4%) was found, representing a psychomotor change, anhedonia and negative affect factor. Anhedonia and negative affect predicted depression severity (R(2)=0.37, F=20.86, p<0.0001). Anhedonia predicted non-response (OR 6.00, CI 1.46-24.59) and both negative affect (OR 5.69, CI 1.19-27.20) and anhedonia predicted non-remission (OR 9.28, CI 1.85-46.51).

LIMITATIONS

The sample size of the study was relatively modest, limiting the number of variables included in the analysis.

CONCLUSIONS

Results confirm that psychomotor change, anhedonia and negative affect are key MDD dimensions, two of which are related to treatment outcome.

Racial and ethnic differences in depressive subtypes and access to mental health care in the United States

OBJECTIVES

Racial and ethnic minorities in the U.S. underutilize mental health service for mood disorders. This study sought to identify depressive subtypes associated with low use of mental health services across racial and ethnic groups based on a large, nationally representative sample of adults in the U.S.

METHODS

Based on latent class analysis, we identified the latent profile of depressive symptoms among those who endorsed lifetime depressed mood or anhedonia in the 2001-2002 National Epidemiological Survey on Alcohol and Related Condition (302 Asian Americans; 8602 Whites; 2266 Blacks; 2254 Hispanics). Proportions and types of lifetime mental health service use across depressive symptom subtypes were assessed and compared across the racial and ethnic categories.

RESULTS

A four class model of depressive subtypes was examined across race and ethnicity ("mild," "cognitive," "psychosomatic," and "severe"). Asian Americans, blacks, and Hispanics with "severe" subtype of depression had significantly lower odds of mental health service use compared to whites with "severe" subtype of depression. While Asian Americans did not have higher proportion of "psychosomatic" subtype than other race and ethnic groups, Asian Americans with "cognitive" subtype of depression significantly underused mental health services compared to Asian Americans with "psychosomatic" subtype of depression (Odds ratio:0.34, 95% Confidence interval:0.13,0.91).

LIMITATION

We were unable to account for heterogeneity of the subethnic group compositions based on country of origin and other socio-demographic factors.

CONCLUSIONS

A targeted outreach intervention to raise awareness among Asian Americans, blacks, and Hispanics with "severe" subtype and Asian Americans with "cognitive" subtype of depression may reduce disparity in mental health service utilization across racial and ethnic groups.

Immigrant Preadolescents and Risk of Emotional Distress

Background:

The question of whether immigrants have more emotional problems than their non-immigrant peers has yielded mixed results. In Norway, there has been a tendency toward immigrant youth reporting higher rates of emotional problems. In addition to studying levels of emotional problems across those with immigrant backgrounds, there is a need to investigate whether the phenomenology of these problems is comparable across ethnic groups.

Objectives:

We used latent class analysis (LCA) to identify subgroups of preadolescents with distinct types of emotional problems in a multiethnic sample in Norway and to investigate associations with immigrant status after controlling for other demographic and risk factors related to emotional problems.

Methods:

Preadolescents between the ages of 10 and 12 years (n = 1042) completed a questionnaire that assessed emotional problems and sociodemographic factors such as gender, grade level, city, economic hardship, school hassles, and parental achievement values. LCA was used to identify subgroups of preadolescent emotional problems. Multinomial logistic regressions were conducted to assess the relationships between these subgroups and the presence of an immigrant background with four immigrant groups (all backgrounds, Pakistan, Turkey, and Sri Lanka). The reference group was the ethnic Norwegians.

Results:

LCA identified three classes according to the severity of the problems; these were labeled healthy, borderline, and distressed. Multinomial logistic regression analyses found the presence of an immigrant background as compared with a non-immigrant background to increase the odds of a person belonging to the distressed class by an approximate factor of 2, depending on the immigrant group. This finding remained consistent after controlling for risk factors.

Conclusions:

These findings suggest that, even as early as preadolescence, the presence of an immigrant background may significantly increase the odds of an individual belonging to a subgroup characterized by emotional distress (as compared with belonging to a healthy class). These findings also suggest similarity across ethnic backgrounds with regard to the expression of emotional problems during preadolescence. This is the first study to identify classes of emotional problems among specific preadolescent immigrant groups.

Latent subtypes of depression in a community sample of older adults: can depression clusters predict future depression trajectories?

Identifying sources of heterogeneity in late life depression remains an important focus of psychiatric investigation. Community samples are particularly informative since many older adults have clinically significant depressive symptoms but fail to meet criteria for major depression and older adults generally do not seek treatment for their depressive symptoms. The primary data used for these analyses were those collected in a community-based survey of over 3000 adults age 65 or older followed for up to ten years. Depressive symptoms were measured by the Center for Epidemiologic Studies-Depression scale (CES-D). Latent class analysis was used to identify clusters of participants based on their symptom profiles at baseline. Mixed models were used to examine trajectories of CES-D scores based on cluster assignment. A model with three unique clusters best fit the data. Cluster 1 (59%) had a low probability of any symptom endorsement. Cluster 2 (31%) endorsed as a group some negative affect and somatic symptoms but their endorsement of low positive affect did not differ from Cluster 1. Participants in Cluster 3 (10%) had a higher probability of endorsement of all symptoms compared to Clusters 1 and 2. The results did not appreciably differ when symptom severity was included. Cluster assignment was a significant predictor of change in CES-D score over the ten-year follow-up period, and the effects over time differed by sex. Depressive symptom profiles predict the longitudinal course of depression in a community sample of older adults, findings that are important especially in primary care settings.

Gender differences in symptomatic profiles of depression: results from the São Paulo Megacity Mental Health Survey

BACKGROUND

Few studies have investigated symptomatic subtypes of depression and their correlates by gender.

METHODS

Data are from the São Paulo Megacity Mental Health Survey. Symptom profiles of 1207 subjects (864 women; 343 men) based upon symptoms of the worst depressive episode in lifetime were examined through latent class analysis. Correlates of gender-specific latent classes were analyzed by logistic regression.

RESULTS

For both men and women, a 3-class model was the best solution. A mild class was found in both genders (41.1% in women; 40.1% in men). Gender differences appeared in the most symptomatic classes. In women, they were labeled melancholic (39.3%) and atypical (19.5%), differing among each other in somatic/vegetative symptoms. The melancholic class presented inhibition and eating/sleeping symptoms in the direction of decreasing, whereas the atypical class had increased appetite/weight, and hypersomnia. For men, symptoms that differentiate the two most symptomatic classes were related to psychomotor activity: a melancholic/psychomotor retarded (40.4%) and agitated depression (19.6%). The highest between-class proportion of agitation and racing thoughts was found among men in the agitated class, with similarity to bipolar mixed state.

LIMITATIONS

Analyses were restricted to those who endorsed questions about their worst lifetime depressive episode; the standardized assessment by lay interviewers; the small male sample size.

CONCLUSIONS

The construct of depression of current classifications is heterogeneous at the symptom level, where gender different subtypes can be identified. These symptom profiles have potential implications for the nosology and the therapeutics of depression.

Altered brain function underlying verbal memory encoding and retrieval in psychotic major depression

Psychotic major depression (PMD) is associated with deficits in verbal memory as well as other cognitive impairments. This study investigated brain function in individuals with PMD during a verbal declarative memory task. Participants included 16 subjects with PMD, 15 subjects with non-psychotic major depression (NPMD) and 16 healthy controls (HC). Functional magnetic resonance imaging (fMRI) data were acquired while subjects performed verbal memory encoding and retrieval tasks. During the explicit encoding task, subjects semantically categorized words as either "man-made" or "not man-made." For the retrieval task, subjects identified whether words had been presented during the encoding task. Functional MRI data were processed using SPM5 and a group by condition ANOVA. Clusters of activation showing either a significant main effect of group or an interaction of group by condition were further examined using t-tests to identify group differences. During the encoding task, the PMD group showed lower hippocampus, insula, and prefrontal activation compared to HC. During the retrieval task, the PMD group showed lower recognition accuracy and higher prefrontal and parietal cortex activation compared to both HC and NPMD groups. Verbal retrieval deficits in PMD may be associated with deficient hippocampus function during encoding. Increased brain activation during retrieval may reflect an attempt to compensate for encoding deficits.

Twenty-year depressive trajectories among older women

CONTEXT

Despite the frequent occurrence of depressive symptoms among older adults, especially women, little is known about the long-term course of late-life depressive symptoms.

OBJECTIVE

To characterize the natural course of depressive symptoms among older women (from the young old to the oldest old) followed up for almost 20 years.

DESIGN

Using latent-class growth-curve analysis, we analyzed women enrolled in an ongoing prospective cohort study (1988 through 2009).

SETTING

Clinic sites in Baltimore, Maryland; Minneapolis, Minnesota; the Monongahela Valley near Pittsburgh, Pennsylvania; and Portland, Oregon.

PARTICIPANTS

We studied 7240 community-dwelling women 65 years or older.

MAIN OUTCOME MEASURE

The Geriatric Depression Scale short form (score range, 0-15) was used to routinely assess depressive symptoms during the follow-up period.

RESULTS

Among older women, we identified 4 latent classes during 20 years, with the predicted probabilities of group membership totaling 27.8% with minimal depressive symptoms, 54.0% with persistently low depressive symptoms, 14.8% with increasing depressive symptoms, and 3.4% with persistently high depressive symptoms. In an adjusted model for latent class membership, odds ratios (ORs) for belonging in the increasing depressive symptoms and persistently high depressive symptoms classes, respectively, compared with a group having minimal depressive symptoms were substantially and significantly (P < .05) elevated for the following variables: baseline smoking (ORs, 4.69 and 7.97), physical inactivity (ORs, 2.11 and 2.78), small social network (ORs, 3.24 and 6.75), physical impairment (ORs, 8.11 and 16.43), myocardial infarction (ORs, 2.09 and 2.41), diabetes mellitus (ORs, 2.98 and 3.03), and obesity (ORs, 1.86 and 2.90).

CONCLUSIONS

During 20 years, almost 20% of older women experienced persistently high depressive symptoms or increasing depressive symptoms. In addition, these women had more comorbidities, physical impairment, and negative lifestyle factors at baseline. These associations support the need for intervention and prevention strategies to reduce depressive symptoms into the oldest-old years.

Latent class-derived subgroups of depressive symptoms in a community sample of older adults: the Cache County Study

OBJECTIVE

We sought to identify possible subgroups of elders that varied in depressive symptomatology and to examine symptom patterns and health status differences between subgroups.

METHODS

The Cache County memory study is a population-based epidemiological study of dementia with 5092 participants. Depressive symptoms were measured with a modified version of the diagnostic interview schedule-depression. There were 400 nondemented participants who endorsed currently (i.e., in the past 2 weeks) experiencing at least one of the three "gateway" depressive symptoms and then completed a full depression interview. Responses to all nine current depressive symptoms were modeled using the latent class analysis.

RESULTS

Three depression subgroups were identified: a significantly depressed subgroup (62%), with the remainder split evenly between a subgroup with low probability of all symptoms (21%), and a subgroup with primarily psychomotor changes, sleep symptoms, and fatigue (17%). Latent class analysis derived subgroups of depressive symptoms and Diagnostic and statistical manual of mental disorders, fourth edition depression diagnostic group were nonredundant. Age, gender, education, marital status, early or late onset, number of episodes, current episode duration, and functional status were not significant predictors of depression subgroup. The first subgroup was more likely to be recently bereaved and had less physical health problems, whereas the third subgroup were less likely to be using antidepressants compared with the second subgroup.

CONCLUSIONS

There are distinct subgroups of depressed elders, which are not redundant with the Diagnostic and statistical manual of mental disorders, fourth edition classification scheme, offering an alternative diagnostic approach to clinicians and researchers. Future work will examine whether these depressive symptom profiles are predictive of incident dementia and earlier mortality.

Meta-review of depressive subtyping models

BACKGROUND

Increasing dissatisfaction with the non-specificity of major depression has led many to propose more specific depressive subtyping models. The present meta-review seeks to map dominant depressive subtype models, and highlight definitions and overlaps.

METHODS

A database search in Medline and EMBASE of proposed depressive subtypes, and limited to reviews published between 2000 and 2011, was undertaken. Of the more than four thousand reviews, 754 were judged as potentially relevant and provided the base for the present selective meta-review.

RESULTS

Fifteen subtype models were identified. The subtypes could be divided into five molar categories of (1) symptom-based subtypes, such as melancholia, psychotic depression, atypical depression and anxious depression, (2) aetiologically-based subtypes, exemplified by adjustment disorders, early trauma depression, reproductive depression, perinatal depression, organic depression and drug-induced depression, (3) time of onset-based subtypes, as illustrated by early and late onset depression, as well as seasonal affective disorder, (4) gender-based (e.g. female) depression, and (5) treatment resistant depression. An overview considering definition, bio-psycho-social correlates and the evidence base of treatment options for each subtype is provided.

LIMITATIONS

Despite the large data base, this meta-review is nevertheless narrative focused.

CONCLUSIONS

Subtyping depression is a promising attempt to overcome the non-specificity of many diagnostic constructs such as major depression, both in relation to their intrinsic non-specificity and failure to provide treatment-specific information. If a subtyping model is to be advanced it would need, however, to demonstrate differential impacts of causes and treatments.

Clinical subtypes of depression are associated with specific metabolic parameters and circadian endocrine profiles in women: the power study

BACKGROUND

Major depressive disorder (MDD) has been associated with adverse medical consequences, including cardiovascular disease and osteoporosis. Patients with MDD may be classified as having melancholic, atypical, or undifferentiated features. The goal of the present study was to assess whether these clinical subtypes of depression have different endocrine and metabolic features and consequently, varying medical outcomes.

METHODS

Premenopausal women, ages 21 to 45 years, with MDD (N = 89) and healthy controls (N = 44) were recruited for a prospective study of bone turnover. Women with MDD were classified as having melancholic (N = 51), atypical (N = 16), or undifferentiated (N = 22) features. Outcome measures included: metabolic parameters, body composition, bone mineral density (BMD), and 24 hourly sampling of plasma adrenocorticotropin (ACTH), cortisol, and leptin.

RESULTS

Compared with control subjects, women with undifferentiated and atypical features of MDD exhibited greater BMI, waist/hip ratio, and whole body and abdominal fat mass. Women with undifferentiated MDD characteristics also had higher lipid and fasting glucose levels in addition to a greater prevalence of low BMD at the femoral neck compared to controls. Elevated ACTH levels were demonstrated in women with atypical features of depression, whereas higher mean 24-hour leptin levels were observed in the melancholic subgroup.

CONCLUSIONS

Pre-menopausal women with various features of MDD exhibit metabolic, endocrine, and BMD features that may be associated with different health consequences.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00006180.

Melancholia

PURPOSE OF REVIEW

The key question for melancholia is whether it should have status as a separate disorder and the literature of the last 12-24 months is surveyed largely from that perspective.

RECENT FINDINGS

A number of interesting findings have appeared across a broad range of issues, but, with the possible exception of some large clinical trials, remain largely unreplicated.

SUMMARY

Supporters of melancholia as a distinct entity will find little comfort in the recent literature.

Heterogeneity in symptom profiles among older adults diagnosed with major depression

BACKGROUND

Late-life depression may be undiagnosed due to symptom expression. These analyses explore the structure of depressive symptoms in older patients diagnosed with major depression by identifying clusters of patients based on their symptom profiles.

METHODS

The sample comprised 366 patients enrolled in a naturalistic treatment study. Symptom profiles were defined using responses to the Center for Epidemiologic Studies Depression Scale (CES-D), the Hamilton Rating Scale for Depression (HAM-D) and the depression section of the Diagnostic Interview Schedule (DIS) administered at enrollment. Latent class analysis (LCA) was used to place patients into homogeneous clusters. As a final step, we identified a risk profile from representative items across instruments selected through variable reduction techniques.

RESULTS

A model with four discrete clusters provided the best fit to the data for the CES-D and the DIS depression module, while three clusters best fit the HAM-D. Using LCA to identify clusters of patients based on their endorsement of seventeen representative symptoms, we found three clusters of patients differing in ways other than severity. Age, sex, education, marital status, age of onset, functional limitations, level of perceived stress and subjective social support were differentially distributed across clusters.

CONCLUSIONS

We found considerable heterogeneity in symptom profiles among older adults with an index episode of major depression. Clinical indicators such as depression history may play less of a role differentiating clusters of patients than variables such as stress, social support, and functional limitations. These findings can help conceptualize depression and potentially reduce misdiagnosis for this age group.

Identification of distinct depressive symptom trajectories in women following surgery for breast cancer

OBJECTIVE

Depressive symptoms, common in breast cancer patients, may increase, decrease, or remain stable over the course of treatment. Most longitudinal studies have reported mean symptom scores that tend to obscure interindividual heterogeneity in the symptom experience. The identification of different trajectories of depressive symptoms may help identify patients who require an intervention. This study aimed to identify distinct subgroups of breast cancer patients with different trajectories of depressive symptoms in the first six months after surgery.

METHOD

Among 398 patients with breast cancer, growth mixture modeling was used to identify latent classes of patients with distinct depressive symptom profiles. These profiles were identified based on Center for Epidemiological Studies-Depression (CES-D) scale scores completed just prior to surgery, and 1, 2, 3, 4, 5, and 6 months after surgery.

RESULTS

Four latent classes of breast cancer patients with distinct depressive symptom trajectories were identified: Low Decelerating (38.9%), Intermediate (45.2%), Late Accelerating (11.3%), and Parabolic (4.5%) classes. Patients in the Intermediate class were younger, on average, than those in the Low Decelerating class. The Intermediate, Late Accelerating, and Parabolic classes had higher mean baseline anxiety scores compared to the Low Decelerating class.

CONCLUSIONS

Breast cancer patients experience different trajectories of depressive symptoms after surgery. Of note, over 60% of these women were classified into one of three distinct subgroups with clinically significant levels of depressive symptoms. Identification of phenotypic and genotypic predictors of these depressive symptom trajectories after cancer treatment warrants additional investigation.

Parental depression and offspring psychopathology: a children of twins study

BACKGROUND

Associations between parental depression and offspring affective and disruptive disorders are well documented. Few genetically informed studies have explored the processes underlying intergenerational associations.

METHOD

A semi-structured interview assessing DSM-III-R psychiatric disorders was administered to twins (n=1296) from the Australian Twin Register (ATR), their spouses (n=1046) and offspring (n=2555). We used the Children of Twins (CoT) design to delineate the extent to which intergenerational associations were consistent with a causal influence or due to genetic confounds.

RESULTS

In between-family analyses, parental depression was associated significantly with offspring depression [hazard ratio (HR) 1.52, 95% confidence interval (CI) 1.20-1.93] and conduct disorder (CD; HR 2.27, CI 1.31-3.93). Survival analysis indicated that the intergenerational transmission of depression is consistent with a causal (environmental) inference, with a significant intergenerational association in offspring of discordant monozygotic (MZ) twin pairs (HR 1.39, CI 1.00-1.94). Logistic regression analysis suggested that the parental depression-offspring CD association was due to shared genetic liability in the parents and offspring. No intergenerational association was found when comparing the offspring of discordant MZ twins [odds ratio (OR) 1.41, CI 0.63-3.14], but offspring of discordant dizygotic (DZ) twins differed in their rates of CD (OR 2.53, CI 0.95-6.76). All findings remained after controlling for several measured covariates, including history of depression and CD in the twins' spouses.

CONCLUSIONS

The mechanisms underlying associations between parental depression and offspring psychopathology seem to differ depending on the outcome. The results are consistent with a causal environmental role of parental depression in offspring depression whereas common genetic factors account for the association of parental depression and offspring CD.

Rural residence and risk for perinatal depression: a Canadian pilot study

Few studies have examined whether rural residence is associated with increased or decreased risk for postpartum depression (PPD). To address this research gap, this pilot study examined rates of depressive symptoms and perceived social support among women living in rural (population <10,000), semi-rural (population 10,000-20,000), and urban (downtown Toronto, population approximately 2.5 million) areas. Women were consecutively recruited at 25-35 weeks gestation from midwifery clinics and hospital-based prenatal care practices in two catchment areas and asked to complete a demographic questionnaire including postal code. On the basis of their responses, rural, semi-rural, and urban mothers were contacted by telephone at 36 weeks gestation (baseline) and 6-8 weeks postpartum (primary outcome). During each assessment, participants completed standardized measures of social connectedness, mental health, and health service utilization, including the Edinburgh Postnatal Depression Scale (EPDS) and the Medical Outcome Study Social Support Scale. A total of 87 participants [N = 23 rural (R), N = 23 semi-rural (SR), N = 41 urban (U)] were recruited into the study. There were no statistically significant differences between groups in mean EPDS scores during pregnancy (U = 7.1, SR = 5.3, R = 5.3, p = 0.15) or at 6 weeks postpartum (U = 5.3, SR = 4.4, R = 4.2, p = 0.43). The proportion of women with EPDS scores >12 similarly did not differ between groups. There were few statistically significant differences between groups on indicators of social connectedness; however, urban women reported significantly lower scores on measures of social network diversity and social capital than either the semi-rural or rural groups. This pilot study is limited by its small sample size; however, our data do not support the hypothesis that there are clinically important differences in risk for PPD associated with rural residence. Further studies examining potential relationships between indicators of social connectedness and perinatal mental health may be warranted.

A latent class analysis of DSM-IV criteria for pathological gambling: Results from the National Epidemiologic Survey on Alcohol and Related Conditions

With rapid increases in gambling opportunities over the past decade, gambling has emerged as an important social and public health concern. The pending revision of the Diagnostic and Statistical Manual of Mental Disorders (DSM) has prompted a flurry of empirical research evaluating the extant diagnostic classification scheme; however few studies have evaluated the pathological gambling criteria. This paper utilized latent class analysis (LCA) to empirically derive and validate a typology of gamblers. LCA was applied to the 10 DSM-IV pathological gambling criteria utilizing data from the 2001-2002 National Epidemiologic Survey on Alcohol and Related Conditions (n=11,104). LCA identified three latent classes which largely differed according to severity. The majority of respondents were assigned to the no gambling problems class (93.3%). Gamblers in the moderate gambling problems class (6.1%) primarily endorsed the preoccupation, tolerance, and chasing criteria. The pervasive gambling problems class (0.6%) endorsed the majority of the criteria. A number of significant differences between the classes emerged as a function of demographic, psychiatric and substance use disorders. The findings offer a heuristic and clinically useful typology of gamblers. Support for a continuum of gambling-related problems reiterate the need for assessment, prevention, and treatment strategies that reflect this more nuanced understanding of gambling.

An item response analysis of the DSM-IV criteria for major depression: findings from the Australian National Survey of Mental Health and Wellbeing

BACKGROUND

This study examines the psychometric properties and presence of gender bias in the major depression criteria using data from the Australian general population.

METHODS

Data came from a subsample of respondents from the 1997 National Survey of Mental Health and Wellbeing (NSMHWB; n=2061). A two-parameter logistic model was employed to yield severity and discrimination parameters, and the IRT log-likelihood-ratio test for differential item functioning (IRTLRDIF) procedure was utilized to evaluate gender bias.

RESULTS

DIF analyses indicated that the psychomotor difficulties criterion was endorsed at lower levels of severity by males than females. In general, the criteria were arrayed along a continuum of depression severity. Discrimination was greatest for concentration difficulties/indecision and lowest for death/suicidal thoughts and worthlessness/guilt. Worthlessness/guilt, psychomotor difficulties, and death/suicidal thoughts tapped the severe end of the depression continuum, whereas concentration difficulties/indecision and sleep disturbance tapped the mild range.

LIMITATIONS

The inclusion of stem questions precluded examination of two core symptoms of depression (depressed mood and loss of interest).

CONCLUSIONS

Collectively, the criteria performed well in defining a latent continuum of major depression. Few gender differences were observed, with the exception of the psychomotor difficulties criterion. Quantitative and qualitative analyses collectively hold promise of providing a scientifically rigorous basis for empirically-based modifications to the psychiatric classification system.

Trajectories of maternal symptoms of anxiety and depression. A 13-year longitudinal study of a population-based sample

Background

There is a lack of population-based studies of developmental trajectories following mothers throughout the whole child-rearing phase and there are few longitudinal studies focusing on both symptoms of depression and anxiety. The aim of the current study is to identify latent trajectory groups based on counts of symptoms of anxiety and depression among mothers throughout the child-rearing phase and the relations of the latent groups to maternal socio-demographic variables.

Methods

Data is from a prospective, longitudinal study of nearly 1000 families in Norway followed from when the index children were 18 months until they were 14.5 years old (the TOPP study). The study used latent profile analysis (LPA) to identify latent groups of mothers with distinct trajectories across time of symptom counts. Latent group differences on socio-demographic variables were tested with one-way ANOVAs, chi-square tests and exact tests.

Results

Six trajectories based on maternal scores from six waves of data collection of symptoms of anxiety and depression were identified; a 'No symptoms' group with mothers without symptoms; a 'Low' group with mothers reporting low symptom levels; a 'Moderate-low' group with mothers reporting moderately low symptom levels; a 'Moderate' group with mothers with moderate symptoms; a 'High-chronic' group with mothers with overall high symptom levels; and a 'Low-rising' group with mothers starting with a low symptom level that increased over time. The mothers in the High-chronic symptom group differed from the other mothers on several socio-demographic variables. They were significantly younger than the mothers in the Low group comprising the oldest mothers. The mothers in the High-chronic group had significantly lower education, were less likely to have paid work and were less likely to be living with a partner than the mothers in the other groups.

Conclusions

The study shows socio-demographic differences between mothers classified into six trajectory groups based on symptoms of anxiety and depression covering 13 years of the child-rearing period. Specific socio-demographic risk factors characterised mothers in the High-chronic symptom group. Identifying subgroups with enduring problems might inform more targeted preventive efforts.

Deconstructing major depression: a validation study of the DSM-IV symptomatic criteria

BACKGROUND

The DSM-IV symptomatic criteria for major depression (MD) derive primarily from clinical experience with modest empirical support.

METHOD

The sample studied included 1015 (518 males, 497 females) Caucasian twins from a population-based registry who met criteria for MD in the year prior to the interview. Logistic regression analyses were conducted to compare the associations of: (1) single symptomatic criterion, (2) two groups of criteria reflecting cognitive and neurovegetative symptoms, with a wide range of potential validators including demographic factors, risk for future episodes, risk of MD in the co-twin, characteristics of the depressive episode, the pattern of co-morbidity and personality traits.

RESULTS

The individual symptomatic criteria showed widely varying associations with the pattern of co-morbidity, personality traits, features of the depressive episode and demographic characteristics. When examined separately, these two criteria groups showed robust differences in their patterns of association, with the validators with the cognitive criteria generally producing stronger associations than the neurovegetative.

CONCLUSIONS

Among depressed individuals, individual DSM-IV symptomatic criteria differ substantially in their predictive relationship with a range of clinical validators. These results challenge the equivalence assumption for the symptomatic criteria for MD and suggest a more than expected degree of 'covert' heterogeneity among these criteria. Part of this heterogeneity is captured by the distinction between cognitive versus neurovegetative symptoms, with cognitive symptoms being more strongly associated with most clinically relevant characteristics. Detailed psychometric evaluation of DSM-IV criteria is overdue.

Poor performance on cognitive tasks in depression: Doing too much or not enough?

Depressed people perform poorly on cognitive tasks. It is unclear whether these deficits are due to decreased devotion of task-related resources or to increased attention to non-task-related information. In the present study, we examined the degree to which depressed and healthy adults displayed pupillary motility that varied at the frequency of presented stimuli on a cognitive task, which we interpreted as task-related processing, and at other frequencies, which we interpreted as reflecting intrinsic processing. Depressed participants made more consecutive errors than did controls. More pupillary motility at other frequencies was associated with poorer performance, whereas more pupillary motility at the frequency of presented stimuli was associated with better performance. Depressed participants had more pupillary motility at other frequencies, which partially mediated observed deficits in cognitive performance. These findings support the hypothesis that allocating cognitive resources to intrinsic processing contributes to observed cognitive deficits in depression.