Childhood adversity and anxiety versus dysthymia co-morbidity in major depression

BACKGROUND: Childhood adversity places individuals with major depression at risk for anxiety and dysthymia co-morbidity. The goal of the present paper is to broaden this area of research by examining specificity between the type of adversity (e.g. abuse versus neglect/indifference) and the resulting co-morbid disorder (e.g. anxiety versus dysthymia co-morbidity). METHOD: The volunteer sample consisted of 76 women meeting Diagnostic and Statistical Manual (DSM-IV) criteria for major depression. Of these, 28 were diagnosed with a co-morbid anxiety disorder and 21 were diagnosed with co-morbid dysthymia. Childhood physical abuse, sexual abuse, psychological abuse, antipathy and indifference were assessed using a contextual interview and rating system. RESULTS: Severe sexual abuse and psychological abuse were significantly and preferentially associated with co-morbid anxiety, while severe physical abuse was significantly and preferentially associated with co-morbid dysthymia. Indifference and antipathy were significantly associated with both co-morbid anxiety and dysthymia. Multivariate analyses revealed that severe sexual abuse was the adverse childhood experience most strongly associated with co-morbid anxiety. CONCLUSIONS: These results suggest that particular adverse experiences in childhood do set up specific vulnerabilities to the expression of anxiety versus dysthymia co-morbidity in adulthood major depression. Cognitive mediators of these associations are discussed as avenues of future research.     

The relationship between social anxiety disorder and alcohol use disorders: a critical review

Epidemiological studies have demonstrated a significant co-morbidity between social anxiety disorder (SAD) and alcohol use disorders (AUDs). Despite the fact that many studies have demonstrated strong relationships between SAD and AUD diagnoses, there has been much inconsistency in demonstrating causality or even directionality of the relationship between social anxiety and alcohol-related variables. For example, some studies have showed a positive relationship between social anxiety and alcohol-related variables, while others have shown a negative relationship or no relationship whatsoever. In an attempt to better understand the relationship between social anxiety and alcohol, some researchers have explored potential moderating variables such as gender or alcohol expectancies. The present review reports on what has been found with regard to explaining the high co-morbidity between social anxiety and alcohol problems, in both clinical and non-clinical socially anxious individuals. With a better understanding of this complex relationship, treatment programs will be able to better target specific individuals for treatment and potentially improve the efficacy of the treatments currently available for individuals with co-morbid SAD and AUD.     

Features associated with suicide attempts in recurrent major depression

Sixty-seven individuals with recurrent major depression and a history of suicide attempts are compared with 163 individuals with recurrent major depression and no history of suicide attempts. The groups are contrasted on demographic features, clinical course, severity of depression, co-morbidity, and acute symptom profiles. Patients with a history of attempts are distinguished from non-attempters by suicidal ideation, marital isolation, neurovegetative signs, feelings of failure, and co-morbid alcoholism or bipolar II disorder. Logistic regression analysis using a model which included a portion of the significant variables correctly classified 77% of the cases. These findings are discussed with reference to prediction of suicide attempts in individuals with major affective disorder.     

Social phobia in the Australian National Survey of Mental Health and Well-Being (NSMHWB)

BACKGROUND: This article reports data on social phobia from the first large scale Australian epidemiological study. Prevalence rates, demographic correlates and co-morbidity in the sample that met criteria for social phobia are reported and gender differences examined. METHOD: Data were obtained from a stratified sample of 10641 participants as part of the Australian National Survey of Mental Health and Well-Being (NSMHWB). A modified version of the Composite International Diagnostic Interview (CIDI) was used to determine the presence of social phobia, as well as other DSM-IV anxiety, affective and substance use disorders. The interview also screened for the presence of nine ICD-10 personality disorders, including anxious personality disorder, the equivalent of DSM-IV avoidant personality disorder (APD). RESULTS: The estimated 12 month prevalence of social phobia was 2.3%, lower than rates reported in several recent nationally representative epidemiological surveys and closer to those reported in the Epidemiological Catchment Area study (ECA) and other DSM-III studies. Considerable co-morbidity was identified. Data indicated that the co-morbidity with depression and alcohol abuse and dependence were generally subsequent to onset of social phobia and that the additional diagnosis of APD was associated with a greater burden of affective disorder. Social phobia most often preceded major depression, alcohol abuse and generalized anxiety disorder. CONCLUSIONS: Social phobia is a highly prevalent, highly co-morbid disorder in the Australian community. Individuals with social phobia who also screen positively for APD appear to be at greater risk of co-morbidity with all surveyed disorders except alcohol abuse or dependence.     

Non-linear relationships in associations of depression and anxiety with alcohol use

BACKGROUND: Many studies have demonstrated co-morbidity of alcohol abuse/dependence with mood and anxiety disorders but relatively little is known about anxiety and depression across the full continua of alcohol consumption and problems associated with drinking. METHODS: Participants from a general population sample (N = 2725) aged 18-80 years completed the Alcohol Use Disorders Identification Test (AUDIT) and four measures of negative affect (two depression and two anxiety symptom scales) included in a self-completion questionnaire. RESULTS: High consumption, AUDIT total score, and AUDIT problems score were associated with high negative affect scores in participants under 60 years old (ORs in the range 1.80-2.83). Graphical and statistical analyses using continuous measures of alcohol use/problems and negative affect identified non-linear relationships where abstainers and occasional drinkers, as well as heavy and problem drinkers, were at risk of high anxiety and depression levels. This pattern, however, was not found in those aged > or = 60 years. The U-shaped relationship was not an artefact of abstainers being typical of the general population in their distribution of negative affect. CONCLUSIONS: Studies of co-morbidity should acknowledge the possibility of non-linear associations and employ both continuous and discrete measures. Abstainers, as well as heavy drinkers, are at increased risk of symptoms of depression and anxiety disorders. Psychosocial factors may play a role in the U-shaped relationship between alcohol consumption and mortality.     

Obsessive-compulsive disorder and separation anxiety co-morbidity in early onset panic disorder.

BACKGROUND: This study was undertaken to examine the relationship between anxiety co-morbidity and age of onset of panic disorder. METHODS: Age of onset of panic disorder and co-morbid anxiety disorders were assessed among 201 panic disorder probands with childhood separation anxiety disorder, obsessive-compulsive disorder, obsessive-compulsive symptoms, social phobia and specific phobia as part of a clinician-administered lifetime diagnostic interview. A generalized linear model was used to test the association between each anxiety co-morbidity and age of panic disorder onset while simultaneously controlling for the potential confounding effects of sociodemographic characteristics and other psychiatric co-morbidity. RESULTS: Earlier onset of panic disorder was found in patients with co-morbid obsessive-compulsive disorder, obsessive-compulsive symptoms and separation anxiety disorder, but not simple phobia or social phobia. Patients with both childhood separation anxiety disorder and obsessive-compulsive disorder had an even earlier panic onset than those with either childhood separation anxiety disorder or obsessive-compulsive disorder. CONCLUSIONS: The association between anxiety co-morbidity and earlier onset of panic disorder is specific to obsessive-compulsive disorder and childhood separation anxiety disorder.     

Family study of subthreshold psychopathology in a community sample

BACKGROUND: There has been increasing interest in the validity and familial transmission of subthreshold psychiatric conditions and the relationship between subthreshold conditions and full syndrome (FS) disorders. However, most of these studies examined a single subthreshold condition and thus fail to take into account the high co-morbidity among subthreshold conditions and between subthreshold conditions and FS disorders. METHOD: A family study of subthreshold psychiatric conditions was conducted with 739 community-drawn young adults and their 1744 relatives. We examined (1) whether relatives of probands with subthreshold major depression, bipolar disorder, anxiety disorders, alcohol use, substance use, and/or conduct disorder exhibited an increased rate of the corresponding (homotypic) FS disorder; (2) whether subthreshold disorders were associated with increased familial rates of other (heterotypic) FS disorders; (3) whether subthreshold and FS conditions are associated with similar familial liabilities; and (4) whether these homotypic and heterotypic associations persisted after controlling for co-morbidity. RESULTS: Significant homotypic associations were observed for subthreshold anxiety, alcohol, conduct, and a trend was observed for major depression. Only the homotypic association for alcohol and conduct remained after controlling for co-morbid subthreshold and FS conditions. Many heterotypic associations were observed and most remained after controlling for co-morbidity. CONCLUSIONS: It is important to broaden the study of subthreshold psychopathology to multiple disorders. In particular cases, controlling for co-morbidity with other subthreshold and FS conditions altered the patterns of familial aggregation. Etiological processes that are common to particular disorders and subthreshold conditions are discussed.     

Family study of co-morbidity between major depressive disorder and anxiety disorders

BACKGROUND: Numerous studies have documented high rates of co-morbidity between major depressive disorder (MDD) and the anxiety disorders (ANX). However, the reason for this is unclear. Family studies provide one potentially useful approach for addressing this issue. METHOD: We explored six explanations of the co-morbidity between MDD and ANX using a family study of a large community sample of young adults and their first-degree relatives. Participants included 112 probands with a lifetime history of both MDD and one or more ANX, 290 probands with a history of MDD but no ANX, 43 probands with a history of one or more ANX but no MDD. 352 probands with no lifetime history of either MDD or ANX, and the probands' 2608 first-degree relatives. Probands were assessed using semi-structured diagnostic interviews on two occasions in adolescence and a third time at age 24. Diagnostic data on relatives were collected using both direct and family history interviews. RESULTS: Compared with controls, MDD aggregated in the families of probands with MDD, whether or not they had co-morbid ANX; ANX aggregated in the families of probands with ANX, regardless of whether they had co-morbid MDD; and co-morbid MDD/ANX aggregated only in the families of probands with both MDD and ANX. The relatives of probands with ANX alone had a significantly higher rate of ANX than the relatives of probands with MDD alone, although none of the other comparisons between the depressed and anxious groups were significant. CONCLUSIONS: This pattern of findings is largely, although not completely, consistent with the view that MDD and ANX are transmitted independently within families, and suggests that the comorbidity between MDD and ANX is caused by non-familial aetiological factors.     

Anxiety disorders and the onset of depression among adults in the community

OBJECTIVE: To determine the association between anxiety disorders, panic attack and the risk of major depression among adults in the community. METHOD: Data were drawn from the Epidemiologic Catchment Area Program survey waves 1 (N = 20291) and 2 (N = 15849). Multivariate logistic regression analyses were used to determine the risk of incident major depression at 12-month follow-up (wave 2) associated with each anxiety disorder and panic attacks assessed at wave 1, adjusting for differences in sociodemographic characteristics, and then controlling simultaneously for all anxiety disorders, and other psychiatric co-morbidity. RESULTS: Specific phobia (OR = 1.7 (1.6, 1.8)), agoraphobia (OR = 2.3 (2.2, 2.5)), obsessive-compulsive disorder (OR = 5.4 (5.0, 5.8)) and panic attack (OR = 1.9 (1.8, 2.1)) each made an independent contribution to the risk of major depression, which persisted after adjusting simultaneously for sociodemographic differences and other psychiatric co-morbidity. CONCLUSIONS: Each anxiety disorder and panic attacks appear to confer an independent risk for the onset of major depression within 12-months among adults in the community. Understanding the key role played by anxiety in depression onset is needed for prevention strategies.     

The prevalence and co-morbidity of subthreshold psychiatric conditions

BACKGROUND: In previous studies of subthreshold conditions, co-morbidity has been largely ignored. The purpose was to examine rates of co-morbidity among subthreshold disorders and between subthreshold and full-syndrome disorders for the major non-psychotic classes of disorders from DSM-IV. METHOD: Participants came from the Oregon Adolescent Depression Project (mean age=16.6 years; females=52.1%). On the basis of a diagnostic interview (K-SADS), participants were assigned to eight subthreshold disorders (MDD, bipolar, eating, anxiety, alcohol use, substance use, conduct, ADHD). RESULTS: Of the 1704 adolescents in the analyses, 52.5% had at least one subthreshood disorder. Of those, 40.0% had also experienced a co-morbid subthreshold condition, and 29.9% of those had a second co-morbid subthreshold condition. Of those with a subthreshold, 36.4% also had a full syndrome. The subthreshold forms of externalizing disorders were co-morbid with each other. As expected, subthreshold anxiety was co-morbid with subthreshold MDD but subthreshold anxiety was also co-morbid with subthreshold alcohol, conduct, and ADHD. The pattern of co-morbidities was nearly identical for males and females. CONCLUSIONS: The hypotheses that externalizing disorders would be co-morbid with other externalizing disorders and that internalizing disorders would be co-morbid with other internalizing disorders was partially supported. Co-morbidities between subthreshold disorders and between subthreshold disorders and full syndrome should impact future research and clinical practice. The assessment of subthreshold disorders needs to include the assessment of other subthreshold and full-syndrome conditions.     

Epidemiology of insomnia, depression, and anxiety

STUDY OBJECTIVES: This study used empirically validated insomnia diagnostic criteria to compare depression and anxiety in people with insomnia and people not having insomnia. We also explored which specific sleep variables were significantly related to depression and anxiety. Finally, we compared depression and anxiety in (1) different insomnia types, (2) Caucasians and African Americans, and (3) genders. All analyses controlled for health variables, demographics, organic sleep disorders, and symptoms of organic sleep disorders. DESIGN: Cross-sectional and retrospective. PARTICIPANTS: Community-based sample (N=772) of at least 50 men and 50 women in each 10-year age bracket from 20 to more than 89 years old. MEASUREMENTS: Self-report measures of health, sleep, depression, and anxiety. RESULTS: People with insomnia had greater depression and anxiety levels than people not having insomnia and were 9.82 and 17.35 times as likely to have clinically significant depression and anxiety, respectively. Increased insomnia frequency was related to increased depression and anxiety, and increased number of awakenings was also related to increased depression. These were the only 2 sleep variables significantly related to depression and anxiety. People with combined insomnia (ie, both onset and maintenance insomnia) had greater depression than did people with onset, maintenance, or mixed insomnia. There were no differences between other insomnia types. African Americans were 3.43 and 4.8 times more likely to have clinically significant depression and anxiety than Caucasians, respectively. Women had higher levels of depression than men. CONCLUSION: These results reaffirm the close relationship of insomnia, depression, and anxiety, after rigorously controlling for other potential explanations for the relationship.     

The effects of anxiety, substance use and conduct disorders on risk of major depressive disorder

BACKGROUND: Major depressive disorder (MDD) is highly co-morbid with other Axis I disorders, which commonly precede its onset. We sought to determine the level and periods of risk for MDD posed by prior or co-occurring psychiatric disorders. METHOD: Using retrospective data from a longitudinal, population-based sample of 2926 male and 1929 female adult twin subjects, we predicted the hazard rates for MDD from a Cox proportional hazards model with same-year or prior onsets of co-morbid Axis I disorders as time-dependent covariates. RESULTS: All axis I disorders studied (generalized anxiety disorder, panic disorder, phobia, alcohol dependence, psychoactive substance use disorders and conduct disorder) significantly predicted increased risk for developing MDD. The highest hazard rates occurred for MDD onsets that co-occurred with those of the co-morbid disorder. However, the risk for onset of MDD subsequent to that of prior disorders is also significantly increased and remains relatively unchanged over time. Although the risk for onset of MDD is significantly higher in women than men, this was not explained by gender differences in prior disorder prevalence or increased sensitivity in women to the effects of prior disorders on risk for depression. CONCLUSIONS: Prior psychiatric disorders are significant risk factors for the development of MDD, independent of the length of the intervening period between the onset of the first disorder and that of MDD.     

Sertraline in the treatment of mixed anxiety and depression disorder

BACKGROUND: Mixed anxiety and depression disorder (MAD) has been recognized in ICD-10 as a diagnostic group including those anxious and depressed patients which do not fit sufficient criteria for any major axis I disorders. MAD is usually treated as a combination of anxiety and depression, although there are data indicating that selective serotonin reuptake inhibitors (SSRIs) might be active on both anxiety and depression. METHOD: 38 patients diagnosed of MAD according to ICD-10 criteria were treated with flexible doses of sertraline for 8 weeks. Benzodiazepines were not allowed during the trial. Efficacy was evaluated with the Clinical Global Impression (CGI) improvement scale and with Hamilton's depression and anxiety Scales. Personality scales, including the Cloninger's TCI and Eysenck's EPQ, were used to test the predictive value of personality traits in the response to treatment. RESULTS: Anxiety was reduced by 55% and depression by 60% in Hamilton scales. At week 8, 29 patients were considered responders (CGI 1 ó 2). Two patients discontinued the trial, only one of them due to adverse events. The mean dose of sertraline was 83.4 mg/day. CONCLUSION: Sertraline showed an excellent tolerability in patients with mixed anxiety-depression disorder despite high levels of baseline anxiety. The response level was high and similar to that reported for patients with major depression. These results warrant further controlled trials to assess the efficacy of SSRIs in MAD.     

Good treatment outcomes in late-life depression with comorbid anxiety

BACKGROUND: Late-life depression studies have found that comorbid anxiety, as a symptom or comorbid disorder, is associated with poorer treatment response and increased likelihood of dropout. This study evaluated the impact of comorbid anxiety on response, dropouts, and side effects, in elderly subjects treated for depression. METHODS: We analyzed data from a 12-week trial comparing nortriptyline and paroxetine in 116 patients aged 60 and older with depression. Subjects classified as having anxious depression were compared to those with nonanxious depression in terms of treatment response rate, time to response, dropout rate, and early side effects. The analysis was replicated with another study, in which 125 subjects aged 69 and older were treated openly with paroxetine and interpersonal psychotherapy. RESULTS: Anxious and nonanxious groups did not differ in terms of response rates, time to response, dropout rates, or time to dropout. Side effects declined more quickly and more significantly in the anxious group than in the nonanxious group. LIMITATIONS: Subjects were treated in a specialty mental health setting, and the findings may not apply in other settings. CONCLUSIONS: We found no association between comorbid anxiety and a poorer prognosis during acute treatment of late-life depression. For elderly patients with anxious depression, standardized treatment in the mental health sector is associated with a good response.     

Typologies of anxiety, depression and somatization symptoms among primary care attenders with no formal mental disorder.

BACKGROUND: Typologies of anxiety, depression and somatization symptoms were investigated in individuals with no formal mental disorders, making no a priori assumptions about symptom distribution and inter-relationship. METHOD: The subjects were 1617 adult primary care attenders from the WHO Collaborative Project on Psychological Problems in General Health Care, with at least three symptoms of anxiety, depression and/or somatization, but with no formal ICD-10 disorders. Analyses were based on the grade of membership model, a multivariate statistical procedure exploring indistinct boundaries between disease categories and preserving the heterogeneity of clinical picture within each category. RESULTS: Six prototype categories (or pure types) best described the structure of symptoms included in analyses. Pure type I included the full set of somatization symptoms. Pure type II was characterized by most anxiety and depression symptoms. Pure type III resembled generalized anxiety disorder. Pure type IV consisted of individuals reporting sporadic symptoms of anxiety, depression or somatization. Pure type V defined individuals with sleep problems. Finally, pure type VI was characterized by anxiety symptoms, including panic-like symptoms. CONCLUSIONS: These findings provide support to the existence of a mixed anxiety-depression category crossing the diagnostic boundaries of current anxiety and depression disorders. Moreover, criteria of anxiety and somatization disorders may be re-examined to assess whether lower diagnostic thresholds can be identified that both preserve the symptom profile and clinical features of current diagnostic categories and allow for a better characterization of individuals with substantial psychopathology though not meeting the high symptom thresholds required for a diagnosis of formal mental disorders.     

The influence of anxiety as a risk to early onset major depression.

OBJECTIVE: we seek to identify and quantify any risk provided by several expressions of "anxiety" to major depression overall, and to separate melancholic and non-melancholic sub-types. METHOD: a sample of 269 patients with a current major depressive episode was assessed for rates of separate formalised anxiety disorders, both for lifetime and prior to the initial depressive episode. We also sought for evidence of familial anxiety and, early childhood expression of anxiety forerunners, measured both state and trait anxiety levels as well as anxiety at a "personality" level, and assessed use of anxiolytic medications. Depressive sub-typing was undertaken using DSM-IV criteria, while "early onset" (EO) depression was defined as an initial onset at 25 years or less, and subsequently re-examined with a cut-off age of 20 years or less. RESULTS: overall. 42% of our sample were assigned as having EO depression, with there being a higher representation of non-melancholic than melancholic EO subjects (i.e., 51% vs. 29%), arguing for sub-type status being respected in the analyses. For both melancholic and non-melancholic subjects two trait anxiety items ("tense"; "keyed up/on edge") were over-represented, suggesting that such a tense anxiety style may provide an antecedent risk to depression (of either sub-type) or be a consequence of depression. Specificity was most evident in the non-melancholic sub-sample, where EO depression was associated with a family history of anxiety, early childhood expressions of anxiety and with two lifetime anxiety disorders (social phobia and obsessive-compulsive disorder). Broadly similar results were returned when "EO" definition was reduced to 20 years or less. CONCLUSIONS: our study is consistent with previous research in identifying anxiety in the form of social inhibition or social avoidance as being particularly likely to precede and perhaps be a conduit to early onset non-melancholic major depression. This conclusion both sharpens risk factor research and indicates an important fulcrum that could be used to assist primary prevention of the depressive disorders.     

The co-morbidity of anxiety and depression in the perspective of genetic epidemiology. A review of twin and family studies

BACKGROUND: Co-morbidity within anxiety disorders, and between anxiety disorders and depression, is common. According to the theory of Gray and McNaughton, this co-morbidity is caused by recursive interconnections linking the brain regions involved in fear, anxiety and panic and by heritable personality traits such as neuroticism. In other words, co-morbidity can be explained by one disorder being an epiphenomenon of the other and by a partly shared genetic etiology. The aim of this paper is to evaluate the theory of Gray and McNaughton using the results of genetic epidemiological studies. METHOD: Twenty-three twin studies and 12 family studies on co-morbidity are reviewed. To compare the outcomes systematically, genetic and environmental correlations between disorders are calculated for the twin studies and the results from the family studies are summarized according to the method of Klein and Riso. RESULTS: Twin studies show that co-morbidity within anxiety disorders and between anxiety disorders and depression is explained by a shared genetic vulnerability for both disorders. Some family studies support this conclusion, but others suggest that co-morbidity is due to one disorder being an epiphenomenon of the other. CONCLUSIONS: Discrepancies between the twin and family studies seem partly due to differences in used methodology. The theory of Gray and McNaughton that neuroticism is a shared risk factor for anxiety and depression is supported. Further research should reveal the role of recursive interconnections linking brain regions. A model is proposed to simultaneously investigate the influence of neuroticism and recursive interconnections on co-morbidity.     

Treatment resistant depression and axis I co-morbidity.

BACKGROUND: Treatment resistant depression (TRD) continues to present a formidable challenge to clinicians, accounts for over half of the annual costs associated with treatment for depression and causes great frustration to patients. Although there have been studies attempting to define TRD, little information is available as to the cause of TRD. One suggestion is that patients with TRD have a greater frequency of co-morbid psychiatric disorders, which explains their resistance to standard antidepressant treatments. The objective of this study was to compare the co-morbidity of Axis I disorders between a sample of TRD patients and a sample of non-TRD patients. METHODS: TRD and non-TRD patients, recruited from two separate antidepressant treatment studies, were assessed for Axis I co-morbidity using the SCID-P for the DSM-III-R. Patients for the two samples were then matched for baseline HAM-D-17 total score and gender. RESULTS: Results reveal that non-TRD patients had a higher rate of both lifetime and current generalized anxiety disorder co-morbidity than did the TRD patients. No other statistically significant differences in Axis I co-morbidity were found. CONCLUSIONS: These findings do not support the idea that current or lifetime Axis I co-morbidity is more common in TRD than non-TRD patients. In fact, the only statistical difference showed non-TRD patients with higher co-morbidity rates.     

Chronic insomnia as a risk factor for developing anxiety and depression

STUDY OBJECTIVE: To study prospectively the relations of insomnia to the development of anxiety disorders and depression in a population-based sample. DESIGN: Cohort study based on data from 2 general health surveys of the adult population. SETTING: Two general health surveys in the adult population in Nord-Tr?ndelag County of Norway, HUNT-1 performed in 1984-6 and HUNT-2 in 1995-7 PARTICIPANTS: Participants without significant anxiety and depression in HUNT-1 were categorized according to the presence and absence of insomnia in the 2 surveys (N=25,130). MEASUREMENTS AND RESULTS: Anxiety disorders and depression in HUNT-2 were assessed by the Hospital Anxiety and Depression Scale and analyzed using multivariate logistic regression analysis adjusted for age, gender, education, comorbid depression/anxiety, and history of insomnia. Anxiety disorders in HUNT-2 were significantly associated with the group with insomnia in HUNT-1 only (OR 1.6; 95% CI, 1.1-2.3), the group with insomnia in HUNT-2 only (OR 3.4; 95% CI, 3.1-3.8), as well as with the group with insomnia in both surveys (OR 4.9; 95% CI, 3.8-6.4). Depression in HUNT-2 was significantly associated with the group with insomnia in HUNT-2 only (OR 1.8; 95% CI, 1.6-2.0), but not with the groups with insomnia in HUNT-1 only or with insomnia in both surveys. CONCLUSIONS: Only a state-like association between insomnia and depression was found. In addition to being a state marker, insomnia may be a trait marker for individuals at risk for developing anxiety disorders. Results are consistent with insomnia being a risk factor for the development of anxiety disorders.