Distinguishing anxiety and depression with field survey data

Cross-lags and the unbiased estimation of life-history and demographic parameters

Biological processes exhibit complex temporal dependencies due to the sequential nature of allocation decisions in organisms' life cycles, feedback loops and two-way causality. Consequently, longitudinal data often contain cross-lags: the predictor variable depends on the response variable of the previous time step. Although statisticians have warned that regression models that ignore such covariate endogeneity in time series are likely to be inappropriate, this has received relatively little attention in biology. Furthermore, the resulting degree of estimation bias remains largely unexplored. We use a graphical model and numerical simulations to understand why and how regression models that ignore cross-lags can be biased, and how this bias depends on the length and number of time series. Ecological and evolutionary examples are provided to illustrate that cross-lags may be more common than is typically appreciated and that they occur in functionally different ways. We show that routinely used regression models that ignore cross-lags are asymptotically unbiased. However, this offers little relief, as for most realistically feasible lengths of time-series conventional methods are biased. Furthermore, collecting time series on multiple subjects-such as populations, groups or individuals-does not help to overcome this bias when the analysis focusses on within-subject patterns (often the pattern of interest). Simulations, a literature search and a real-world empirical example together suggest that approaches that ignore cross-lags are likely biased in the direction opposite to the sign of the cross-lag (e.g. towards detecting density dependence of vital rates and against detecting life-history trade-offs and benefits of group living). Next, we show that multivariate (e.g. structural equation) models can dynamically account for cross-lags, and simultaneously address additional bias induced by measurement error, but only if the analysis considers multiple time series. We provide guidance on how to identify a cross-lag and subsequently specify it in a multivariate model, which can be far from trivial. Our tutorials with data and R code of the worked examples provide step-by-step instructions on how to perform such analyses. Our study offers insights into situations in which cross-lags can bias analysis of ecological and evolutionary time series and suggests that adopting dynamical models can be important, as this directly affects our understanding of population regulation, the evolution of life histories and cooperation, and possibly many other topics. Determining how strong estimation bias due to ignoring covariate endogeneity has been in the ecological literature requires further study, also because it may interact with other sources of bias.

Trouble anxieux et dépressif mixte : problèmes cliniques

Le trouble anxieux et dépressif mixte (ADM) représente une nouvelle catégorie diagnostique regroupant essentiellement des patients vus dans le cadre des soins primaires. Ces patients se définissent comme des sujets présentant des symptômes d’anxiété et de dépression d’intensité limitée et comparable, s’accompagnant au moins de quelques signes neurovégétatifs. En outre, ces patients sont censés ne pas répondre aux critères diagnostiques spécifiques de troubles anxieux ou dépressifs. Cependant, les cas de dépression anxieuse ne sont pas limités aux patients entrant dans cette nouvelle catégorie « sous-syndromale ». De nombreux patients qui répondent aux critères soit de troubles dépressifs soit de troubles anxieux peuvent également présenter des symptomes, un syndrome ou répondre à un diagnostic d’anxiété ou de dépression. On ne sait pas encore si les symptômes d’anxiété et de dépression sont deux expressions différentes d’un même processus psychopathologique sous-jacent. La description récente d’un « syndrome névrotique généralisé » (Tyrer, 1990) représente une tentative de réunification de syndromes séparés dans nos classifications actuelles. Avec cette approche globale, les états d’anxiété,de dépression ou d’ADM sont associés, à un moment ou à un autre, à des traits de personnalité spécifiques et on considère qu’ils expriment différents niveaux d’hyperréactivité à diverses situations stressantes. Cette hypothèse expliquerait le rapport étroit entre ces deux catégories de symptômes, et I’efficacité dont témoignent certains agents psychopharmacologiques à la fois sur les troubles anxieux et dépressifs.

Mental Health in Mariel Cubans and Haitian Boat People

This article presents prevalence data on four specific mental disorders in samples of 452 Cuban immigrants who arrived during the Mariel crisis and 500 Haitians who arrived at about the same time. The disorders are: Major Depressive Disorder, Anxiety Disorder, Alcohol Disorder, and Psychosis. Cubans had higher rates of disorder than Haitians at all levels of education and income, but only in the Cuban sample was the standard inverse relationship between socioeconomic status and rate of mental disorder observed. These and other results presented suggest no single theory can explain the relationship of immigration to the range of specific mental disorders.

Race, Class, and Psychological Distress: Contextual Variations across Four American Communities

Analyses investigating the role of race and class in the propensity to psychological distress have yielded conflicting results. We contend that one reason for this inconsistency is that previous studies, based on empirical data drawn from different places and times, have interpreted results without reference to the distinctive racial contexts across the country. Because the specific local conditions in which individuals live differentially expose blacks and whites of different socioeconomic classes to psychological stressors, we seek to better understand how race and class patterns in distress are conditioned by place of residence. To examine the links between race, class, place, and distress, we conduct a quantitative analysis using data from the multi-site Epidemiological Catchment Area (ECA) program, which shows different relationships between distress, race, and class across four US communities. We then investigate these differences across place through a qualitative study of the local structural conditions that contextualize these relationships. Our historical review indicates that racial conditions vary substantially across the four sites, in accordance with our empirical analyses. We conclude that epidemiological research will be theoretically enriched and intervention strategies more effective as researchers design improved measures for the specific contextual conditions in which factors related to human health are embedded.

GENESiS: creating a composite index of the vulnerability to anxiety and depression in a community-based sample of siblings

There is considerable evidence for a unitary and dimensional view of the genetic vulnerability to symptoms of anxiety and depression. The GENESiS (Genetic Environmental–Nature of Emotional States in Siblings) Study aims to use a multivariate approach to detect genetic loci that contribute to individual differences in this vulnerability dimension. The study used the UK General Practice Research Framework to generate a community-based sample of siblings. Questionnaire measures of anxiety/depression included the short form of the neuroticism scale from the revised Eysenck Personality Questionnaire (EPQ-N), the General Health Questionnaire (GHQ-12), and the anxious arousal and high positive affect subscales from the Mood and Anxiety Symptoms Questionnaire (MASQ-AA and MASQ-HPA). Genetic model-fitting of 2658 unselected sibships provided evidence for a single common genetic (familial) factor that accounted for a substantial proportion of the genetic variances and covariances of these four measures. Using the parameter estimates of this model, we constructed a composite index of this common genetic factor. This index, which has a sib correlation of 0.22, will be used as a quantitative phenotype in the molecular genetic phase of GENESiS. Twin Research (2000) 3, 316–322.

Twenty-five-year course and outcome in anxiety and depression in the Upper Bavarian Longitudinal Community Study

OBJECTIVE

Assessment of 25-year course of pure and mixed anxiety and depression in a community sample.

METHOD

Participants were grouped into pure anxiety, pure depression, mixed anxiety and depression, and no anxiety or depressive syndrome at baseline. Assessments consisted of a: i) baseline survey, ii) 5-year follow-up, iii) 25-year follow-up. Self-rating scales as well as expert-rating interviews yielded data on social and psychopathological risk factors and outcome measures.

RESULTS

Baseline prevalence for mixed anxiety and depressive syndrome was 8.7%. Subjects with combined anxiety and depressive syndrome were more predisposed towards later adverse mental health outcomes and reduced functionality. The transition from anxiety syndrome (pure and mixed) to depressive syndrome over the 25-year study is more likely than the reverse. Logistic regression analysis emphasized the impact of early anxiety syndromes on later depression.

CONCLUSION

Results underscore the long-term risks of suffering from a combined anxiety and depressive syndrome.

Use of administrative data for the surveillance of mood and anxiety disorders

OBJECTIVE

There is increasing interest in the use of administrative data for surveillance and research in Australia. The purpose of the present study was to evaluate the usefulness of such data for the surveillance of mood and anxiety disorder using databases from the following Canadian provinces: British Columbia, Ontario, Quebec and Nova Scotia.

METHOD

A population-based record-linkage analysis was done using data from physician billings and hospital discharge abstracts, and community-based clinics using a case definition of ICD-9 diagnoses of 296.0-296.9, 311.0, and 300.0-300.9.

RESULTS

The prevalence of treated mood and/or anxiety disorder was similar in Nova Scotia, British Columbia, and Ontario at approximately 10%. The prevalence for Quebec was slightly lower at 8%. Findings from the provinces showed consistency across age and sex despite variations in data coding. Women tended to show a higher prevalence overall of mood and anxiety disorder than men. There was considerably more variation, however, when treated anxiety (300.0-300.9) and mood disorders (296.0-296.9, 311.0) were considered separately. Prevalence increased steadily to middle age, declining in the 50s and 60s, and then increased after 70 years of age.

CONCLUSIONS

Administrative data can provide a useful, reliable and economical source of information for the surveillance of treated mood and/or anxiety disorder. Due to the lack of specificity, however, in the diagnoses and data capture, it may be difficult to conduct surveillance of mood and anxiety disorders as separate entities. These findings may have implications for the surveillance of mood and anxiety disorders in Australia with the development of a national network for the extraction, linkage and analysis of administrative data.

Anxiety: its role in the history of psychiatric epidemiology

BACKGROUND

The role played by anxiety in the history of psychiatric epidemiology has not been well recognized. Such lack of understanding retarded the incremental growth of psychiatric research in general populations. It seems useful to look back on this history while deliberations are being carried out about how anxiety will be presented in DSM-V.

METHOD

Drawing on the literature and our own research, we examined work that was carried out during and after the Second World War by a Research Branch of the United States War Department, by the Stirling County Study, and by the Midtown Manhattan Study. The differential influences of Meyerian psychobiology and Freudian psychoanalysis are noted.

RESULTS

The instruments developed in the early epidemiologic endeavors used questions about nervousness, palpitations, sweating, trembling, shortness of breath, upset stomach, etc. These symptoms are important features of what the clinical literature called 'manifest', 'free-floating' or 'chronic anxiety'. A useful descriptive name is 'autonomic anxiety'.

CONCLUSIONS

Although not focusing on specific circumstances as in Panic and Phobic disorders, a non-specific form of autonomic anxiety is a common, disabling and usually chronic disorder that received empirical verification in studies of several community populations. It is suggested that two types of general anxiety may need to be recognized, one dominated by excessive worry and feelings of stress, as in the current DSM-IV definition of Generalized Anxiety Disorder (GAD), and another emphasizing frequent unexplainable autonomic fearfulness, as in the early epidemiologic studies.

The Upper Bavarian longitudinal community study 1975-2004. 2. Long-term course and outcome of depression. A controlled study

OBJECTIVE

The study describes course and outcome over 25 years in depressed and non-depressed men and women from a large community study. Outcome measures covered psychopathology, disability, and impaired functioning.

METHOD

A depressive syndrome (depressed mood and three additional depressive symptoms) was defined and compared to a control condition without depressive symptoms in the seven days preceding baseline assessment. Assessments focused on three time points: baseline survey, 5-year follow-up, and 25-year follow-up. Self-rating scales as well as expert-rating interviews yielded data on a wide range of social and psychopathological risk factors and outcome measures.

RESULTS

Among participants of all three waves (N=838), the baseline prevalence for depressive syndrome was 18.1%. Depressive symptoms manifest at the first wave had substantial impact over the 25-year study. Subjects with a depressive syndrome were predisposed for later adverse mental health outcomes, more disability in social domains and reduced functionality. No long-term increase or decrease of the prevalence of the depressive syndrome was observed.

CONCLUSION

There is a persistent and long lasting impact of depressive syndrome, irrespective of diagnostic status, in the general population. Our results underscore the importance of sub-syndromal depressive syndrome when estimating the risk of future mental disorders and functional impairment in the long-term.

Anxiety and depression: a 40-year perspective on relationships regarding prevalence, distribution, and comorbidity

OBJECTIVE

Building on a report about the prevalence of depression over time, this paper examines historical trends regarding anxiety in terms of its prevalence, its distribution by age and gender, and its comorbidity with depression. Methods for conducting such time trend analysis are reviewed.

METHOD

Representative samples of adults were selected and interviewed in 1952, 1970, and 1992. Logistic regressions were used for statistical analysis.

RESULTS

Although twice as common as depression, the prevalence of anxiety was equally stable. Anxiety was consistently and significantly more characteristic of women than men. A re-distribution of rates in 1992 indicated that depression but not anxiety had significantly increased among younger women (P = 0.03). Throughout the study, approximately half of the cases of anxiety also suffered depression.

CONCLUSION

The relationships between anxiety and depression remained similar over time with the exception that depression came to resemble anxiety as a disorder to which women were significantly more vulnerable than men. Social and historical factors should be investigated to assess their relevance to this change.

Migraine, major depression, panic disorder, and personality traits in women aged 40-74 years: a population-based study

This study investigates the associations between migraine on the one hand and lifetime major depression, lifetime panic disorder, and neuroticism evaluated using the Swedish universities Scales of Personality on the other. A neurologist clinically assessed 728 women aged 40-74 years attending a population-based mammography screening programme. The associations between lifetime migraine and personality traits and psychiatric disorders were insignificant in multivariable analysis. However, in old women (60-74 years) the risk for active migraine was strongly associated with a history of major depression and high levels of stress susceptibility and somatic trait anxiety. Furthermore, in old women, high levels of stress susceptibility and somatic trait anxiety were associated with low ratings of migraine pain intensity and lower levels of these traits with high ratings after controlling for disability during migraines, whereas there were only small differences in middle-aged women. The results suggest that certain aspects of neuroticism are important mental correlates of the ability of old women to endure migraine pain.

Women, poverty and common mental disorders in four restructuring societies

BACKGROUND

Poverty and female gender have been found to be associated with depression and anxiety in developed countries. The rationale behind this paper was to bring together five epidemiological data sets from four low to middle income countries to examine whether key economic and development indicators such as income and poor education, and female gender, were associated with common mental disorders.

METHOD

The paper is based on five datasets: three based on primary care attenders in Goa, India; Harare, Zimbabwe and Santiago, Chile; and two based on community samples in Pelotas, Brazil and Olinda, Brazil. All five studies estimated prevalence of common mental disorders along with variables to measure economic deprivation and education.

FINDINGS

In all five studies, female gender, low education and poverty were strongly associated with common mental disorders. When income was divided into tertiles, with the lowest tertile as a reference value, there was a significant trend for reduced morbidity for the lower two tertiles.

DISCUSSION

These findings have considerable implications since the rapid economic changes in all four societies have been associated with rising income disparity and economic inequality. Examples of population based prevention strategies based on increasing the proportion of those who complete schooling and on high-risk strategies such as providing loan facilities to the impoverished are potential outcomes of these findings. Development agencies who focus on women as a priority group have failed to recognize their unique vulnerability to common mental disorders and need to reorient their priorities accordingly.

Anxiety but not depression is associated with elevated blood pressure in a community group of French elderly

OBJECTIVE

This study examined whether anxiety and depression were independently associated with elevated blood pressure in elderly persons.

METHOD

The study group consisted of 1389 subjects aged 59 to 71 years recruited from the electoral rolls of the city of Nantes (France). Subjects completed the Center for Epidemiologic Studies-Depression scale (CES-D) and the Spielberger Inventory scales to assess depressive symptoms and anxiety symptoms, respectively. Data were collected on sociodemographic characteristics, smoking and drinking habits, medical history, and drug use. Two measures of systolic and diastolic blood pressure were taken after a 10-minute rest. Body mass index was computed from weight and height measurements. Subjects taking antihypertensive drugs (N = 281) were excluded from the present analysis.

RESULTS

Depression and anxiety scores were significantly correlated (r = .61 in men; r = .65 in women; p<.001). In univariate analyses, anxiety scores were correlated with systolic and diastolic blood pressure in men, but not in women; blood pressure was not associated with depressive symptoms in either sex. Multivariate logistic regressions, controlling for possible confounders, showed that in both men and women, the risk of high blood pressure increased with increasing anxiety scores; odds ratios for high blood pressure were less than 1 in subjects with depressive symptomatology.

CONCLUSIONS

This study suggested that anxiety but not depression was independently associated with an increased risk for high blood pressure.

The 'research magnificent' in late life: psychiatric epidemiology and the primary health care of older adults

OBJECTIVE

Primary care occupies a strategic positive in the evaluation, treatment, and prevention of the mental disturbances of later life. This article highlights four themes that are crucial to understanding mental disturbances among older adults: 1) subsyndromal depression, 2) coexisting depression and anxiety, 3) comorbidity of depression and chronic medical conditions, and 4) risk factors for cognitive impairment.

METHOD

The literature was selectively reviewed for each theme to ask the central question, "What can primary care physicians learn about mental disturbances of their older patients from epidemiologic and community studies?"

RESULTS

The primary care setting itself is an important venue for an examination of aging issues and mental health. Workers in the "middle ground of psychiatric epidemiology"--primary health care--have not yet reached a full appreciation for the value of research in the primary care setting for enhancing our understanding of the mental disturbances of late life, and how these intersect with other salient factors.

CONCLUSIONS

Primary care physicians and others who work in primary care should advocate for further mental health integration and research in primary care. Research is needed that will lead to new ways of maximizing the health and quality of life of older adults and their families.

Material standard of living, social class, and the prevalence of the common mental disorders in Great Britain

STUDY OBJECTIVE

To test the hypothesis that poor material standard of living is independently associated with the prevalence of the common mental disorders after adjusting for occupational social class, and to estimate the population impact of poor material standard of living on the prevalence of these disorders.

DESIGN

Cross sectional survey. Prevalence of the common mental disorders was assessed using the General Health Questionnaire, a self administered measure of psychiatric morbidity.

PARTICIPANTS

9064 adults aged 16-75 living in private households in England, Wales, and Scotland.

MAIN RESULTS

The common mental disorders were significantly associated with poor material standard of living, including low household income (OR 1.24, 95% CI 1.00, 1.54) and not saving from income (OR 1.29, 95% CI 1.15, 1.45), after adjusting for occupational social class and other potential confounders. An independent association was also found with occupational social class of the head of household among women, but not men, after adjusting for material standard of living. The adjusted population attributable fraction for poor material standard of living (using a five item index) was 24.0%.

CONCLUSIONS

Like mortality and physical morbidity, common mental disorders are associated with a poor material standard of living, independent of occupational social class. These findings support the view that recent widening of inequalities in material standards of living in the United Kingdom pose a substantial threat to health.

Development of a scale to measure symptoms of anxiety and depression in the general UK population: the psychiatric symptom frequency scale

OBJECTIVES

The psychiatric symptom frequency (PSF) scale was developed to assess symptoms of anxiety and depression (i.e. affective symptoms) experienced over the past year in the general population. This study aimed to examine the distribution of PSF scores, internal consistency, and factor structure and to investigate relationships between total scores for this scale and other indicators of poor mental health.

PARTICIPANTS

The Medical Research Council national survey of health and development, a class stratified cohort study of men and women followed up from birth in 1946, with the most recent interview at age 43 when the PSF scale was administered.

MAIN RESULTS

The PSF scale showed high internal consistency between the 18 items (Cronbach's alpha = 0.88). Ratings on items of the scale reflected one predominant factor, incorporating both depression and anxiety, and two additional factors of less statistical importance, one reflecting sleep problems and the other panic and situational anxiety. Total scores were calculated by adding 18 items of the scale, and high total scores were found to be strongly associated with reports of contact with a doctor or other health professional and use of prescribed medication for "nervous or emotional trouble or depression," and with suicidal ideas.

CONCLUSIONS

The PSF is a useful and valid scale for evaluating affective symptoms in the general population. It is appropriate for administration by lay interviewers with minimal training, is relatively brief, and generates few missing data. The total score is a flexible measure which can be used in continuous or binary form to suit the purposes of individual investigations, and provides discrimination at lower as well as upper levels of symptom severity.

Depression and anxiety as a single disorder: evidence from brain stem auditory evoked potentials

Anxiety and depression are often interlinked as demonstrated by clinical, epidemiological, psychopharmacological and even genetic studies. However, robust biochemical and electrophysiological evidence for linkage or separation of mood and anxiety disorders is scarce. Brain stem auditory evoked potentials (BASEP) can easily and non-invasivly be measured in psychiatric patients and reflect neurophysiological processes in the brain stem. The aim of the present study was to evaluate BASEP in drug-free patients suffering from panic disorder or major depression and to compare these to healthy controls. Patients (n = 26; panic = 16, depression = 10) were diagnosed according to Diagnostic and Statistical Manual (DSM)-III-R criteria assessed by the Hamilton Anxiety and Hamilton Depression Scales, and all underwent 3 weeks of medications washout. All subjects (n = 36) completed the study. N3 latency was decreased in the patient group (P < 0.05), N3-5 interval was lengthened (P < 0.05), the N3 latency correlated with anxiety scores and depression scores correlated with the N3 and N5 latency periods. In conclusion, our small sample demonstrated shared electrophysiological variables in panic disorder and depression, further supporting the concept of spectrum disorder.

Anxiety-like and depression-like behavior in Maudsley reactive (MR) and non-reactive (NMRA) rats

1. Female MR ("anxious") and MNRA ("non-anxious") Maudsley rats were tested in the CSD behavioral conflict paradigm (anxiety-like measure) and also in the FST paradigm (depression-like measure). 2. As expected, MNRA rats accepted significantly more shocks in the CSD paradigm than did MR rats (i.e., MNRA rats were less "anxious"), MNRA rats also exhibited significantly less immobility in the FST procedure (i.e., MNRA rats were less easily made "depressed"). 3. When the data were pooled across the two strains, there was a significant correlation between CSD and FST behavioral scores; however, there was no significant correlation between these measures when the data from the two strains were evaluated separately. Multiple regression (independent variables of rat strain and CSD score, dependent variable of FST score) revealed a significant effect of rat strain, but not CSD score, on FST behavior. 4. The relationship of these findings to the apparent relationship between anxiety and depression in humans is discussed.

Reported parental behaviour and adult affective symptoms. 1. Associations and moderating factors

Associations between retrospective ratings of parental behaviour and adult affective symptoms were investigated in a British national sample. Symptom scores at ages 36 and 43 years showed low but significant correlations with care (negative) and control (positive), as measured by the Parental Bonding Instrument. Prevalence of high symptom scores was much greater in respondents with low care-high control (affectionless control) parents than in those with high care-low control parents, but there was no synergistic effect of combined care and control. Degree of affectionless control was progressively related to risk of depression. No significant gender differences were found in these associations. Findings could not be explained as spurious relationships resulting from association with other features of childhood adversity, and there was evidence that distorted recall arising from contemporaneous depressed mood was not responsible. Work is needed to establish the causal mechanisms underlying observed associations, including inter-relationships between parental style and other early adversity, and factors mediating or moderating the long-term of parental behaviour.

Pathways between parental divorce and adult depression

A longitudinal study found high levels of depression in women of divorced parents, but not in men. In childhood there had been few behavioural differences between girls from divorced and intact families. Subsequently, there were significant differences in job-changing during early careers, premarital pregnancy, and own marital breakdown. Greater adult depression was not attributable to social networks, emotional support, recent life events, financial circumstances or the main effect of marital status. A significant interaction reflected little relationship between parental divorce and symptoms for women in first marriages, but a strong relationship in the never married, divorced, and remarried.

Aetiology of anxiety and depressive disorders in an inner-city population. 2. Comorbidity and adversity

An earlier paper documented that adverse experiences in childhood and adolescence considerably raise risk of both depressive and anxiety conditions (with the exception of mild agoraphobia and simple phobia) in adult life. This paper deals with the same inner-city women with children at home. Consideration of adverse experiences throughout adulthood as a whole (excluding the period just before onset) particularly involving major prior losses suggests that rather different aetiological processes may be involved. Depression appears to be often linked to experiences of major loss in adulthood as a whole and to be particularly susceptible to shortcomings in the quality of ongoing social support. For anxiety only early adverse experiences appeared to be critical. (However, the onset of both conditions is often provoked by a severely threatening event in the most recent period--particularly 'loss' in depression, and 'danger' in anxiety.) Finally the critical role of early experience for both anxiety and depression explains to a considerable extent why they so often occur together; and social factors not studied in the present enquiry may account for some of the remaining unexplained comorbidity.

Social factors and recovery from anxiety and depressive disorders. A test of specificity

Analysis of 33 instances of recovery or improvement among 92 women with anxiety, and 49 instances of recovery and improvement among 67 episodes of depression, showed that recovery and improvement, when compared with conditions not changing, were associated with a prior positive event. Such events were characterised by one or more of three dimensions: the 'anchoring' dimension involved increased security; 'fresh-start', increased hope arising from a lessening of a difficulty or deprivation; and 'relief', the amelioration of a difficulty not involving any sense of a fresh start. Events characterised by anchoring were more often associated with recovery or improvement in anxiety, and those characterised as fresh-start were associated with recovery or improvement in depression. Recovery or improvement in both disorders was more likely to be associated with both anchoring and fresh-start events. The study involved the reworking of some social and clinical material, and although done blind should be seen as exploratory.

Observer bias in the assessment of anxiety and depression

Two studies are described here. In the first, an attempt is made to examine the relationship between the complaints of anxiety and depression using the results of a survey of a dermatology clinic. The Hospital Anxiety and Depression scale (HAD) and Clinical Interview Schedule (CIS) were both used in 117 unselected clinic attenders. The results showed that the self-report scales (HAD and first section of CIS) showed a closer relationship between anxiety and depression than the second section of the CIS that requires clinical judgement. In the second study, an attempt was made to distinguish between two possible explanations for this phenomenon; that psychiatrists use the constructs of anxiety and depression more carefully than patients, or alternatively that psychiatrists show an observer bias. A sample of psychiatrists were asked to complete symptom profiles for anxiety and depression; both for an imaginary 'patient' and for their own emotions, allowing psychiatrists' beliefs concerning the relationship between anxiety and depression to be studied. The results indicated that the psychiatrists thought there was a negative correlation between anxiety and depression in patients in contrast to the consistent empirical finding that anxiety and depression are positively correlated. Psychiatrists also thought anxiety and depression were less closely related in patients than in themselves. It is likely that psychiatric assessments of anxiety and depression requiring clinical judgement on the part of the interviewer are subject to observer bias. It is argued that self-report measures of psychiatric symptoms will provide more convincing evidence to resolve diagnostic disputes.

The natural history of anxiety disorders

The article reviews research and presents our results on the natural history of 2 forms of anxiety disorder, panic disorder and generalized anxiety disorder. Data from our epidemiological cohort study give evidence of premorbid anxiousness and overadaptation already in childhood. Distressing conditions in the family are more prevalent among subjects with anxiety disorders or major depression than among controls. Anxiety disorders frequently begin between age 20-30 and can be triggered by life events. The course is often characterized by a certain chronicity that manifests itself in residual symptoms and mild impairment in social roles even after many years and is frequently complicated with depression. The best predictors are severity and duration of symptoms, as well as comorbidity with depression. Future studies of the natural history should take into account these factors in multivariate approaches.

Married with children: predictors of mental and physical health in middle-aged women

The relationship between current mental and physical health and history of education, marriage, child-rearing and employment was studied in 541 women aged 42-50. Participants, recruited from the community for a longitudinal study of risk factors for cardiovascular disease, were all premenopausal and free from major diagnosed physical or mental disorder. Physical health measures included weight, cigarette and alcohol consumption, and current physical symptoms. Self-report psychological measures included depression, anxiety, anger, stress, and coping. Women who were mothers and still in their first marriage ("married with children") were somewhat healthier and happier than others. However, women with only a high school education, even when "married with children," were at a fourfold risk of depression compared with college-educated women, unless they were in paid employment, in which case their risk was not increased. Employment did not affect the risk of depression for college-educated women who were "married with children." Among other women, lack of paid employment more than doubled the risk of depression, whatever the educational level. Among the measures of physical health, the only significant finding was a high rate of smoking among high-school-educated women not in traditional marriages. Possible pathways linking education, marital history and current mental health are discussed.

Socio-economic status, employment and neurosis

In a national sample of over 3,000 36-year-olds, neurosis was more prevalent in men of lower status as assessed by housing tenure but not occupational class, education or personal income. Symptoms were more frequent in the unemployed, especially those not seeking work. In women, rates did not differ by husband's occupational class but were higher for those in rented accommodation, with unskilled manual jobs, without paid employment, with poor qualifications and with unemployed husbands, the strength of associations being dependent upon family structure. Many of these associations were reduced or eliminated by adjustment for reported financial hardship. Accounts of mental health problems in unemployed men and in married women (especially with children) may have underestimated the importance of financial circumstances.

Migraine, psychiatric disorders, and suicide attempts: an epidemiologic study of young adults

To determine the prevalence of migraine and the risks for psychiatric disorders and suicide attempts associated with it, we studied a random sample of 1,007 young adults from a large Health Maintenance Organization in the Detroit, MI area. The lifetime prevalence of migraine was 7% in males and 16.3% in females. The rate of migraine was higher in persons with lower education and was equal in whites and blacks. Persons with migraine were at increased risk for affective and anxiety disorders, nicotine dependence, and alcohol or illicit drug abuse or dependence. There was a consistent trend toward higher psychiatric comorbidity in migraine with aura than in migraine without aura. Coexisting anxiety, which generally preceded migraine, was associated with a marked increase in the odds of major depression. Persons with migraine had higher rates of suicide attempts than persons without migraine. The odds ratio for suicide attempts, adjusted for coexisting major depression and other psychiatric and substance use disorders, in migraine with aura was 3.0 (95% confidence interval, 1.4-6.6). The coexistence of migraine with major depression, anxiety disorders, and suicide attempts has important clinical and research implications.

Depression sub-typing: unitary, binary or arbitrary?

The strongest statistical support for the binary view of depression has been provided by factor (principal components) analytic studies which delineate a bipolar factor with features interpreted as reflecting "endogenous depression" and "neurotic depression" at opposing poles. We review the seminal studies to suggest instead that the bipolar factor has generally polarised depression and anxiety, and that no such entity or symptom complex of "neurotic depression" has been isolated. Instead "neurotic depression" has been defined principally by features of anxiety and personality style. We argue that the suggested entity is, in fact, a pseudo-entity, being no more than a residual group of non-depressive features without any significant intrinsic depressive characteristics. We support our interpretation by showing comparable solutions in published studies of depressives alone, contrasted with separate analyses of anxious and depressed patients. We also report two studies in which the "neurotic depressive" pole is made to appear and disappear by the inclusion and exclusion of anxiety items. As factor analytic studies have defined the "residual" pole so variably, we argue that some features held to distinguish neurotic depression are of no utility and that such a diagnosis is meaningless. We suggest that the clinician should not proceed (after excluding endogenous depression) to conclude that the default option is necessarily an entity "neurotic depression" and that instead a heterogeneous group of options (e.g. anxiety, personality disorder) require review. If the "neurotic depressive" type of the multivariate analytic studies is a pseudo-entity, then a modified unitary view of depression may be valid.

Socioeconomic status (SES) and psychiatric disorders. Are the issues still compelling?

One of the most consistent findings in psychiatric epidemiology prior to 1980 has been that socioeconomic status (SES) was inversely related to the recent prevalence of a variety of important types of disorder. The findings raised and re-raised major issues about the role of adversity in these disorders. In recent years, however, research interest in these issues has been declining. At the same time, marked changes have been taking place in the case identification and diagnostic procedures available for epidemiological research. In this paper, I inquire into whether these changes in diagnostic concepts and methods have led to a change in the "facts" that gave rise to the issues about the role of SES. I rely particularly on results from our on-going epidemiological research in Israel and from the National Institute of Mental Health (NIMH) Epidemiological. Catchment Area (ECA) studies in the United States, reevaluate the shift away from research on the role of SES, and offer suggestions for future research.

Depression and abnormal illness behavior in cancer patients

Evaluation of the incidence of depression among cancer patients has been the object of a number of studies. Recent reports of medically ill patients have indicated that depression is related to several dimensions of abnormal illness behavior (e.g., hypochondriasis, irritability, denial, disease conviction). To investigate the relationship between depression and abnormal illness behavior in cancer patients, a study was conducted of 196 patients with a recent diagnosis of cancer and with a good performance status (Karnofsky score greater than 80). The Hamilton Depression Rating Scale (HDRS) and the Illness Behavior Questionnaire (IBQ) were administered in their validated Italian forms. A cutoff point of 17 on the HDRS revealed 38.26% of the patients as having symptoms of depression, whereas a more conservative cutoff point of 21 indicated a depressive state in 23.97% of the patients. Depressed patients had higher scores on all the IBQ dimensions except that of psychologic versus somatic perception of illness. The results were confirmed by the correlation between the parameters. Higher levels of denial were reported by females and by patients receiving adjuvant or palliative chemotherapy, who had, however, lower levels of dysphoria than patients not receiving treatment. Higher levels of irritability were shown in hospitalized patients. No relationship was found between medical status variables (Karnofsky score, tumor status, and disease extent) and psychologic measures, except for denial. The findings seem to confirm the importance of assessment of depression and illness behavior in cancer patients and suggest the need for more thorough investigation of the psychosocial variables associated with them.

Problems with the differentiation of anxiety and depression

This paper discusses the problems of differentiating anxiety and depression. Assessment of these two clinical states is particularly difficult since they are typically intermingled. Theoretical analysis of the current use of the constructs and a sound psychometric approach can disentangle them. Unfortunately, the most widely used assessment methods do not measure anxiety and depression independently.