The Ability of the Symptom Checklist SCL-90 to Differentiate Various Anxiety and Depressive Disorders

We studied the use of the Symptom Checklist-90 (SCL-90) to differentiate between specific anxiety and depressive disorders and/or their symptoms in 280 patients with 6 DSM-III-R diagnoses: major depression (MD), panic disorder (PD), generalized anxiety disorder (GAD), social phobia (SP), obsessive-compulsive disorder (OCD), and mixed anxiety and depression (MAD). Using a comparison group, we found specific patterns for some of the diagnostic categories. Both the MD and MAD subjects had significantly high paranoid ideation, interpersonal sensitivity, hostility, and psychoticism, as well as high depression subscale scores; those with PD and GAD has the highest anxiety and somatization scores; and those with SP or OCD had a mixed pattern. When ranking the severity of psychopathology, the disorders ordered from most to least were MAD, MD, PD, GAD, SP, and OCD. Subsyndromal levels of symptoms frequently were associated with the various conditions. Use of the SCL-90 subscale helps to enlarge our understanding of the various anxiety and depressive disorders.     

Defining anxious depression: going beyond comorbidity.

OBJECTIVE: Since publication of the DSM-IV, there remains a group of patients with depression and anxiety symptoms who are not well classified. We therefore wanted to determine more accurately the type of patients best described by the term "anxious depression." We also wanted to review the literature to assess the most appropriate treatment(s) for these patients. METHOD: We surveyed the medical literature published after 1994 for all articles containing the relevant terms and assessed all possible articles in detail to determine those relevant to the diagnosis and those that involved relevant clinical studies. RESULTS: The term anxious depression can encompass 3 groups of patients: those with comorbid major depressive disorder (MDD) and an anxiety disorder, those with MDD but with subthreshold anxiety symptoms, and those with subthreshold depressive and subthreshold anxiety symptoms (also called mixed anxiety and depressive disorder). CONCLUSIONS: Based upon our literature review, we believe that the term anxious depression should only be used for the second group; that is, those patients with an MDD and subthreshold anxiety symptoms. From our literature review to determine the most appropriate treatment for this group of patients, it appears likely that drugs inhibiting the reuptake of both noradrenaline and serotonin may have greater clinical utility than single-action drugs such as the selective serotonin reuptake inhibitors (SSRIs). However, it is also clear that much more research needs to be undertaken in this important patient group so that we can better understand its prevalence, clinical features, and treatment.     

Co-occurrence of anxiety and depressive disorders in a community sample of older people: results from the MRC CFAS (Medical Research Council Cognitive Function and Ageing Study)

BACKGROUND: Few population-based studies have examined the whole range of subthreshold syndromes and disorders of anxiety and depression in older people. AIMS: To investigate the co-occurrence of anxiety and depressive syndromes in older people. Associations between these conditions and personal and environmental factors are examined. METHOD: MRC CFAS included 13,004, age 65 years and above, who completed the initial screening interview. A stratified random subsample of 2,640 participated in the assessment interview where the Geriatric Mental State Examination (GMS) was administered. The AGECAT diagnostic system was used to generate subthreshold and disorder-level of anxiety and depression as well as the combination of these into eight syndromes categories plus a group without any of the syndromes categories. Prevalences, unadjusted and adjusted odds ratios are calculated for the syndrome categories in relation to cross-sectional personal and environmental factors, and odds ratios of subthreshold and disorders level are estimated. RESULTS: The overall prevalence of anxiety and depressive disorders are 3.1% and 9.7% respectively. The overall prevalence of either anxiety or depressive disorder (anxiety disorder with subthreshold depression, mixed anxiety and depressive disorder with subthreshold anxiety) where they overlapped is 8.4%. The highest Odds Ratios unadjusted and adjusted for age and gender, of anxiety and depressive disorders and significant for trend are found for increasing disability. Disability has a strong relationship with all the co-morbid syndrome categories. In all analyses women showed significant higher estimates than men. CONCLUSIONS: Our study demonstrated high estimates where anxiety and depression occurred in parallel both as disorders and as subthreshold syndromes.     

Comorbidity of depression and anxiety in nursing home patients

OBJECTIVES: To assess the occurrence and risk indicators of depression, anxiety, and comorbid anxiety and depression among nursing home patients and to determine whether depression and anxiety are best described in a dimensional or in a categorical classification system. METHODS: DSM and subthreshold anxiety disorders, anxiety symptoms, major and minor depression and depressive symptoms were assessed in 333 nursing home patients of somatic wards of 14 nursing homes in the north west of the Netherlands with the Schedules for Clinical Assessment in Neuropsychiatry (SCAN) and the Geriatric Depression Scale (GDS). Comorbidity was studied along a severity gradient. Logistic regression analyses were carried out to identify demographic, health-related, psychosocial and care-related correlates of anxiety and depression. RESULTS: The prevalence of pure depression (PD) was 17.1%, of pure anxiety (PA) 4.8%, and of comorbid anxiety and depression (CAD) 5.1%. Comorbidity increased dependent on severity of both anxiety and depression. Different patterns of risk indicators were demonstrated for PA, PD and CAD for the investigated baseline characteristics. CONCLUSIONS: Comorbidity of anxiety and depression is most prevalent in the more severe depressive and anxious nursing home patients. The gradual increase of comorbidity of anxiety and depression dependent on the levels of severity of depression and anxiety suggests that for nursing home patients a dimensional classification of depression and anxiety is more appropriate than a categorical one. The observed differences in patterns of risk indicators for PA, PD and CAD support a distinguishing of anxiety and depression. Future studies are needed to assess the effect of treatment of PA, PD and CAD in nursing home patients.     

In search of mixed anxiety-depressive disorder: a primary care study

The diagnosis of mixed anxiety-depressive disorder, as proposed in DSM-IV, is intended to be useful in settings such as primary care, where low-level anxiety and depressive symptoms may cause clinically significant impairment but are undiagnosable using current criteria. Evidence of the prevalence of this diagnosis is, however, lacking, particularly since the publication of the proposed diagnostic criteria in DSM-IV. Our study examined symptoms of anxiety and depression in 65 primary care patients screened for anxiety and depression while visiting their doctor. Results indicated that of the 37 patients without a diagnosable anxiety or depressive disorder, none had symptoms of depression and anxiety accompanied by interference that the patient deemed significant and attributable to his or her symptoms. These data dispute the need for a mixed anxiety-depression category (beyond mood and anxiety syndromes currently in DSM-IV) in future editions of the DSM.     

Mixed anxiety-depressive disorder and major depressive disorder: comparison of the severity of illness and biological variables

Mixed anxiety-depressive disorder (MADD) is a new diagnostic category defining patients who suffer from both anxiety and depressive symptoms of limited and equal intensity accompanied by at least some autonomic features. Patients do not meet the criteria for specific anxiety or depressive disorders. The emergence of the symptoms is independent of stressful life events. There are many issues presently under investigation about the validity of this clinical entity. In this study, a group of 29 patients with MADD was compared with a group of 31 patients with major depressive disorder (MDD) to assess the differences and similarities between these two disease categories in terms of severity measures and biological variables. The dexamethasone suppression test (DST) was employed, and thyroid hormones and thyrotropin (TSH) levels were measured for the evaluation of hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-thyroid (HPT) axes, respectively. The patients with MADD were found to be less depressive and more anxious compared to those with MDD. DST responses and thyroid functions were found to be similar in the two groups. When severity of depression was controlled, k(max) and 2300-h cortisol values were found to be significantly higher in the MADD group. Although the patients with MDD and MADD presented with relatively different clinical features, there is not enough biological evidence indicating that MADD represents a discrete diagnostic category. However, there may be relatively higher HPA activity in MADD patients.     

Subthreshold depression in adolescence and mental health outcomes in adulthood

BACKGROUND: There is increasing interest in the extent to which individuals with subthreshold depression face increased risks of subsequent major depression and other disorders. OBJECTIVE: To examine linkages between the extent of depressive symptoms (asymptomatic, subthreshold, major depression) at ages 17 to 18 years and mental health outcomes up to age 25 years in a New Zealand birth cohort. DESIGN: Data were gathered during the Christchurch Health and Development Study, a 25-year longitudinal study of a birth cohort of 1265 New Zealand children (635 males, 630 females). SETTING: General community sample. PARTICIPANTS: The analysis was based on 1006 participants who represented 80% of the original cohort. MAIN OUTCOME MEASURES: Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition symptom criteria for major depression and anxiety disorder, treatment-seeking, suicidal ideation, and suicide attempt. RESULTS: There were significant associations (P<.01) between the extent of depression at ages 17 to 18 years and rates of subsequent depressive symptoms, major depression, treatment for depression, anxiety disorder, treatment for anxiety disorder, suicidal ideation, and suicide attempts. After adjustment for covariate factors, the extent of depression at ages 17 to 18 years remained associated with later depression and suicidal tendencies. Planned comparisons showed that sample members with subthreshold depression had a similar prognosis to those meeting criteria for major depression. CONCLUSIONS: Findings suggest that sample members with subthreshold depression are a group with elevated risks of later depression and suicidal behaviors. Current diagnostic procedures, which classify people with subthreshold depression into complex discrete groups, might obscure the fact that depressive symptoms are dimensional and range from none to severe.     

Subthreshold Depressive Disorder in Adolescents: Predictors of Escalation to Full-Syndrome Depressive Disorders

ObjectivesSubthreshold depressive disorder is one of the best established risk factors for the onset of full-syndrome depressive disorders. However, many youths with subthreshold depressive disorder do not develop full-syndrome depression. We examined predictors of escalation to full-syndrome depressive disorders in a community sample of 225 adolescents with subthreshold depressive disorder.MethodCriteria for subthreshold depressive disorder were an episode of depressed mood or loss of interest or pleasure lasting at least 1 week and at least two of the seven other DSM-IV–associated symptoms for major depression. Participants were assessed four times from mid-adolescence to age 30 years using semistructured diagnostic interviews.ResultsThe estimated risk for escalation to full-syndrome depressive disorders was 67%. Five variables accounted for unique variance in predicting escalation: severity of depressive symptoms, medical conditions/symptoms, history of suicidal ideation, history of anxiety disorder, and familial loading for depression. Adolescents with three or more risk factors had an estimated 90% chance of escalating to full-syndrome depressive disorder, compared with 47% of adolescents with fewer than three risk factors.ConclusionsThese data may be useful in identifying a subgroup of youths with subthreshold depressive disorder who are at especially high risk for escalating to full-syndrome depressive disorders.     

Distress and functioning in mixed anxiety and depressive disorder

The aim of the present study was to evaluate the validity of mixed anxiety and depressive disorder (MADD) with reference to functional characteristics and symptomatic characteristics in comparison with anxiety disorders, depressive disorders, and groups showing subthreshold symptoms (exclusively depressive or anxiety related). The present study was carried out in the following three medical settings: two psychiatric and one primary care. Patients seeking care in psychiatric institutions due to anxiety and depressive symptoms and attending primary medical settings for any reason were taken into account. A total of 104 patients (65 women and 39 men, mean age 41.1 years) were given a General Health Questionnaire (GHQ-30), Global Assessment of Functioning (GAF) and Present State Examination questionnaire, a part of Schedules for Clinical Assessment in Neuropsychiatry, Version 2.0. There were no statistically relevant differences between MADD and anxiety disorders in median GHQ score (19 vs 16) and median GAF score (median 68.5 vs 65). When considering depressive disorders the median GHQ score (28) was higher, and median GAF score (59) was lower than that in MADD. In groups with separated subthreshold anxiety or depressive symptoms, median GHQ scores (12) were lower and median GAF scores (75) were higher than that in MADD. The most frequent symptoms of MADD are symptoms of generalized anxiety disorder (GAD) and depression. Mixed anxiety and depressive disorder differs significantly from GAD only in higher rates of depressed mood and lower rates of somatic anxiety symptoms. Distinction from depression was clearer; six of 10 depressive symptoms are more minor in severity in MADD than in the case of depression. Distress and interference with personal functions in MADD are similar to that of other anxiety disorders. A pattern of MADD symptoms locates this disorder between depression and GAD.     

The importance of new antidepressants in the treatment of anxiety/depressive disorders.

Patients suffering from anxiety and depression are often seen in clinical practice. In accordance with the diagnostic criteria of DSM-III/IV and ICD-10, respectively, there may be various combinations of symptoms and degrees of severity. The symptoms of these patients may range from subthreshold anxiety or depression to a combination of anxiety and depressive disorders. Besides giving an extensive survey of diagnostic problems and the epidemiological incidence of such combinations, pharmacotherapeutic approaches are critically reviewed. Metaanalyses have shown that various serotonin reuptake inhibitors (SSRI) are equivalent, if not superior, to tricyclic antidepressants (TCA) in their anti-anxiety effectiveness. Hence, SSRI may be considered a therapy of choice, not least on account of very few adverse effects and good tolerance. More recent antidepressants are under scrutiny for their anti-anxiety efficacy. Citalopram, venlafaxine and, because of its established sedative action, nefazodone seem to be particularly suited to fill a possible therapeutic gap and to provide agitated patients with an alternative to TCA.     

Atypical depression

I have indicated that the concept of atypical depression is as confusing as the concept of atypical psychosis when discussing the “schizophrenias.” Atypical depressions must be distnguished from the typical picture of depressive experience congruent with depressive behavior and biologic or vegetative symptoms.I have divided atypical depression into two major subgroups:Atypical depressions characterized by depressive experience in the absence of biobehavioral symptoms. These atypical depressions have been identified by both British and American psychiatrists and seem to be depressions that are successfully treated by MAO inhibitors.Atypical depressions characterized by biobehavioral symptoms in the absence of depressive experience. The classical patients here include various pain patients, and patients with neurotic symptoms including presentation with anxiety as a major symptom. These patients often respond to antidepressant medication, either tricyclic antidepressants or MAO inhibitors. The third kind of patient presents with neither depressive experience nor biobehavioral symptoms or signs, and responds to antidepressive medication. I do not feel these patients should be diagnosed as atypical depressives. These patients should be considered as undiagnosed patients who have responded to the nonspecific affects of antidepressant medications.By using the diagnostic outline I have discussed, it becomes possible to highlight the typical depressions and compare and contrast them to two major subtypes of atypical depression. In this way, we can avoid confusion when we use the term depression and when we diagnose depressive syndromes.     

Empirical examination of current depression categories in a population-based study: symptoms, course, and risk factors

OBJECTIVE: Research studies on the validity of current diagnostic and subthreshold categories of depression that use a population-based follow-up design are rare. The authors examined the validity and utility of four current depression categories by examining subject transition between categories and the symptoms, course, and risk factors of each. METHOD: A general population sample of 1,920 adults from the Baltimore Epidemiologic Catchment Area 13-year follow-up study were examined. Data on diagnoses, symptoms, course, and risk factors were collected by using the National Institute of Mental Health Diagnostic Interview Schedule, the Life Chart Interview, and an office visit. Polychotomous regression was used to examine the heterogeneity of four diagnostic categories: major depressive disorder, depressive syndrome, dysthymia, and a comorbid depression condition (major depressive disorder and dysthymia). RESULTS: Transitions between the four depression categories occurred over the 13 years. Symptom profiles for the four categories were parallel but differed in severity. Course characteristics among the four categories slightly differed. Risk factor profiles showed significant differences. Family history was associated with both depressive syndrome and major depressive disorder. Stressful life events were most strongly associated with depressive syndrome. Female gender was most strongly associated with the comorbid depression category. CONCLUSIONS: The evidence suggests that except for dysthymia, the depression categories are genetically homogeneous and environmentally heterogeneous. Stress is associated with mild depression, and gender is associated with severe depression. The apparent familial transmission of the subthreshold entity, depressive syndrome, needs further investigation.     

The mood spectrum: improving the diagnosis of bipolar disorder

Although the distinction between bipolar and unipolar disorders served our field well in the early days of psychopharmacology, in clinical practice it is apparent that their phenotypes are only partially described by current diagnostic classification systems. A substantial body of evidence has accrued suggesting that clinical variability needs to be viewed in terms of a broad conceptualization of mood disorders and their common threshold or subthreshold comorbidity. The spectrum model provides a useful dimensional approach to psychopathology and is based on the assumption that early-onset and enduring symptoms shape the adult personality and establish a vulnerability to the subsequent development of Axis-I disorders. To obtain a clearer understanding of the depressive phenotype, it is pivotal that we increase our detection of hypomanic symptoms so that clinicians can better distinguish bipolar II disorder from unipolar depression. Diagnostic criteria sensitive to hypomanic symptoms have been identified that suggest bipolar II disorder is at least as prevalent as major depression. Moreover, the comorbidities of these illnesses are very different and alcoholism in particular appears to be a greater problem in bipolar II disorder than in unipolar depression. Structured clinical interviews and patient self-report questionnaires have also successfully identified the presence of hypomanic symptoms in patients with unipolar disorder and support the concept of a spectrum of bipolar illness. In conclusion, the importance of subthreshold syndromes should not be underestimated as failure to recognize bipolar spectrum disorder could delay treatment and worsen prognosis.     

Detection of subthreshold depression and subthreshold anxiety in the elderly.

OBJECTIVE: To assess the ability of screening instruments to detect subthreshold depression or subthreshold anxiety and to make suggestions for the improvement of instrument performance. DESIGN: Group definition relied on the presence or absence of major psychiatric disorders or of subthreshold disorders (Composite International Diagnostic Interview). SETTING: A community-based study in Germany. PARTICIPANTS: The total sample comprised 274 subjects over 60 years of age; 57 subjects suffered from acute subthreshold depression, 26 subjects suffered from acute subthreshold anxiety, 173 subjects were defined as being healthy (i.e. no acute or lifetime major psychiatric disorder, no acute subthreshold disorder). MEASURES: The short version of the General Health Questionnaire (GHQ-12), the Center for Epidemiologic Studies--Depression Scale (CES-D), the Structured Interview for the Diagnosis of Dementia of the Alzheimer-type, Multiinfarct Dementia and Dementias of other Etiology (SIDAM) for cognitive impairment. RESULTS: Subjects with subthreshold disorders scored higher on the CES-D and the GHQ-12 than healthy individuals. The most distinct increase was observed in the CES-D score of subjects with subthreshold anxiety. The CES-D factor for the presence of somatic/vegetative symptoms performed slightly better compared to the other CES-D factors. CONCLUSIONS: The CES-D moderately detected subthreshold anxiety. Subthreshold depression could not be efficiently detected by either questionnaire. The combination of items indicating the presence of somatic symptoms and depressive affect could improve instrument performance when screening for subthreshold anxiety but not for subthreshold depression.     

Diagnostic criteria for depression in Parkinson's disease: A study of symptom patterns using latent class analysis

Although major depression is one of the most frequent psychiatric disorders among patients with Parkinson's disease, diagnostic criteria have yet to be validated. The main aim of our study was to validate depressive symptoms using latent class analysis for use as diagnostic criteria for major depression in Parkinson's disease. We examined a consecutive series of 259 patients with Parkinson's disease admitted to 2 movement disorders clinics for regular follow‐ups. All patients were assessed with a comprehensive psychiatric interview that included structured assessments for depression, anxiety, and apathy. The main finding was that all 9 Diagnostic and Statistical Manual (4th edition) diagnostic criteria for major depression (ie, depressed mood, diminished interest or pleasure, weight or appetite changes, sleep changes, psychomotor changes, loss of energy, feelings of worthlessness or inappropriate guilt, poor concentration, and suicidal ideation) identified a patient class (severe depression group) with high statistical significance. Latent class analysis also demonstrated a patient class with minimal depressive symptoms (no‐depression group), and a third patient class with intermediate depressive symptoms (moderate depression). Anxiety and apathy were both significant comorbid conditions of moderate and severe depression. Taken together, our findings support the use of the full Diagnostic and Statistical Manual (4th edition) criteria for major depression for use in clinical practice and research in Parkinson's disease and suggest that anxiety may be included as an additional diagnostic criterion. © 2011 Movement Disorder Society     

Clinical significance and comorbidity of subthreshold depression and anxiety in the community

OBJECTIVE: This report examines: 1) the magnitude of co-occurrence of threshold and subthreshold-level depression and anxiety in the community, and 2) the relationship between comorbidity and the diagnostic level of depression and anxiety and their clinical correlates. METHOD: A community sample of 591 subjects was interviewed prospectively five times across 15 years from the ages of 20-35. The diagnostic interview allowed the assignment of diagnoses according to DSM-III criteria and operational definitions of subthreshold syndromes. RESULTS: 1) Comorbidity between depression and anxiety was more frequent when one syndrome reached threshold level; 2) comorbidity at both the threshold and subthreshold diagnostic levels was associated with symptom severity, disability and treatment, whereas the diagnostic level was associated with disability and suicidal attempts. CONCLUSION: The systematic association between comorbidity across diagnostic threshold levels of anxiety and depression with clinical correlates suggests the importance of a more dimensional approach to their classification.     

Agitated depression as a mixed state and the problem of melancholia.

The extensive use of antidepressant drugs in the treatment of all forms of depression makes the question of the real nature of agitated depression a crucial issue because many patients have adverse outcomes, including increased agitation, increased insomnia, increased risk of suicide, and sometimes the onset of psychotic symptoms. Agitated depression is no longer considered a mixed state in the DSM system. After a review of the literature on melancholia agitata as a mixed state and on the introduction of the concept of mixed states, this article has examined the psychopathology of agitated depression. The main symptoms are depressive mood with marked anxiety, restlessness, and often delusions. In other cases, psychic agitation and racing or crowded thoughts prevail alongside anxiety and depressed mood. The mixed nature of these symptoms has been discussed and new diagnostic criteria proposed, including those syndromes without marked restlessness but with evident psychic agitation and racing or crowded thoughts. It is suggested that all the varieties of agitated depression be called mixed depression, with the following diagnostic criteria: A. Major depressive episode B. At least two of the following symptoms: 1. Motor agitation 2. Psychic agitation or intense inner tension 3. Racing or crowded thoughts.     

The course of depression in adult outpatients. Results from the Medical Outcomes Study.

OBJECTIVE--To compare the course of depression during a 2-year period in adult outpatients (n = 626) with current major depression, dysthymia, and either both current disorders ("double depression") or depressive symptoms with no current depressive disorder. METHODS--Depressed patients visiting 523 clinicians (mental health specialists and general medical providers) were identified using a two-stage screening procedure including the Diagnostic Interview Schedule. The course of depression was assessed in 2 follow-up years with a structured telephone interview based on the format of the Diagnostic Interview Schedule. RESULTS--Baseline severity of depressive symptoms was greatest in patients with double depression, but initial functional status was poor in those with dysthymia with or without concurrent major depression. Patients with dysthymia had the worst outcomes, those with current major depression alone had intermediate outcomes, and those with subthreshold depressive symptoms had the best outcomes. Even the latter group, however, had a high incidence (25%) of major depressive episode over 2 years. Initial depression severity and level of functional status accounted for more explained variance in outcomes than did type of depressive disorder. CONCLUSIONS--The findings emphasize the poor prognosis associated with dysthymia even in the absence of major depression; the prognostic significance of subthreshold depressive symptoms; and the clinical significance of assessing level of severity of symptoms as well as functional status and well-being, regardless of type of depressive disorder.     

A comparative study of nonspecific depressive symptoms and minor depression regarding functional impairment and associated characteristics in primary care

BACKGROUND: Milder forms of depression are highly prevalent in the clinical setting as well as in primary care. However, it is still unclear whether there are distinguishable groups among the various subthreshold syndromes and to what extent they are associated with impairment, thus requiring treatment. Therefore, the study aimed at comparing the degree of impairment in 2 groups of subthreshold depressive patients (nonspecific and minor depressive) with nondepressive patients and with major depressive patients. Another aim of the study was to evaluate the spectrum hypothesis of depressive syndromes. SAMPLING AND METHODS: A sample of 619 primary care patients was studied using the self-administered Patient Health Questionnaire (PHQ). After defining subthreshold depressive syndromes on a criterion basis, frequencies, sociodemographic factors, and impairment of nondepressive, subthreshold depressive, and major depressive patients were compared. RESULTS: Nonspecific depressive symptoms (NDS) were diagnosed in 9.1% of the study subjects and minor depression in 6.2%. Subjects with subthreshold depressive disorders did not differ from each other or from subjects with major depression regarding sociodemographic risk factors such as age, sex, or marital status. Yet, a continually increasing impairment from NDS to minor depression to major depression could be found. Moreover, the investigated groups differed with regard to the severity index. CONCLUSIONS: The results of the study are in accordance with the spectrum hypothesis of depressive syndromes ranging from NDS to minor depression to major depression. Patients with subsyndromal depression showed significant functional impairment to the extent that at least some of these patients probably had a disorder requiring treatment.     

Seasonality in depressive and anxiety symptoms among primary care patients and in patients with depressive and anxiety disorders; results from the Netherlands Study of Depression and Anxiety

Background

Little is known about seasonality of specific depressive symptoms and anxiety symptoms in different patient populations. This study aims to assess seasonal variation of depressive and anxiety symptoms in a primary care population and across participants who were classified in diagnostic groups 1) healthy controls 2) patients with a major depressive disorder, 3) patients with any anxiety disorder and 4) patients with a major depression and any anxiety disorder.

Methods

Data were used from the Netherlands Study of Depression and Anxiety (NESDA). First, in 5549 patients from the NESDA primary care recruitment population the Kessler-10 screening questionnaire was used and data were analyzed across season in a multilevel linear model. Second, in 1090 subjects classified into four groups according to psychiatric status according to the Composite International Diagnostic Interview, overall depressive symptoms and atypical versus melancholic features were assessed with the Inventory of Depressive Symptoms. Anxiety and fear were assessed with the Beck Anxiety Inventory and the Fear questionnaire. Symptom levels across season were analyzed in a linear regression model.

Results

In the primary care population the severity of depressive and anxiety symptoms did not show a seasonal pattern. In the diagnostic groups healthy controls and patients with any anxiety disorder, but not patients with a major depressive disorder, showed a small rise in depressive symptoms in winter. Atypical and melancholic symptoms were both elevated in winter. No seasonal pattern for anxiety symptoms was found. There was a small gender related seasonal effect for fear symptoms.

Conclusions

Seasonal differences in severity or type of depressive and anxiety symptoms, as measured with a general screening instrument and symptom questionnaires, were absent or small in effect size in a primary care population and in patient populations with a major depressive disorder and anxiety disorders.