Spin in RCTs of anxiety medication with a positive primary outcome: a comparison of concerns expressed by the US FDA and in the published literature

OBJECTIVES

This study aimed to determine the presence of spin in papers on positive randomised clinical trials (RCTs) of antidepressant medication for anxiety disorders by comparing concerns expressed in the Food and Drug Administration (FDA) reviews with those expressed in the published paper.

METHODS

For every positive anxiety medication trial with a matching publication (n=41), two independent reviewers identified the concerns raised in the US FDA reviews and those in the published literature. Spin was identified when concerns or limitations were expressed by the FDA (about the efficacy of the study drug) but not in the corresponding published paper. Concerns mentioned in the papers but not by the FDA were scored as 'non-FDA' concerns.

FINDINGS

Only six out of 35 (17%) of the FDA concerns pertaining to drug efficacy were reported in the papers. Two papers mentioned a concern that fit the FDA categories, but was not mentioned in the corresponding FDA review. Eighty-seven non-FDA concerns were counted, which often reflected general concerns or concerns related to the study design.

CONCLUSIONS

Results indicate the presence of substantial spin in the clinical trial literature on drugs for anxiety disorders. In papers describing RCTs on anxiety medication, the concerns raised by the authors differed from those raised by the FDA. Published papers mentioned a large number of generic concerns about RCTs, such as a lack of long-term research and limited generalisability, while they mentioned few concerns about drug efficacy. These results warrant the promotion of independent statistical review, reporting of patient-level data, more study of spin, and an increased expectation that authors report FDA concerns.

Sleep quality predicts positive and negative affect but not vice versa. An electronic diary study in depressed and healthy individuals

BACKGROUND

The exact nature of the complex relationship between sleep and affect has remained unclear. This study investigated the temporal order of change in sleep and affect in participants with and without depression.

METHODS

27 depressed patients and 27 pair-matched healthy controls assessed their sleep in the morning and their affect 3 times a day for 30 consecutive days in their natural environment. Daily sleep quality and average positive affect (PA) and negative affect (NA) were used to examine whether changes in sleep quality preceded or followed changes in PA and NA, and whether this was different for patients and healthy controls. Second, presumptive mediating factors were investigated. We hypothesized that fatigue mediated the effect of changes in sleep quality on subsequent PA/NA, and that rumination mediated the effect of changes in PA/NA on subsequent sleep quality.

RESULTS

Multilevel models showed that changes in sleep quality predicted changes in PA (B=0.08, p<0.001) and NA (B=-0.06, p<0.001), but not the other way around (PA: B=0.03, p=0.70, NA: B=-0.05, p=0.60). Fatigue was found to be a significant mediator of the relationship between sleep quality and PA (Indirect Effect=0.03, p<0.001), and between sleep quality and NA (Indirect Effect=-0.02, p=0.01). Rumination was not investigated because of non-significant associations between PA/NA and sleep quality. The associations were not different for patients and controls.

LIMITATIONS

The analyses were restricted to self-reported sleep quality, and conclusions about causality could not be drawn.

CONCLUSIONS

Improvements in sleep quality predicted improvements in affect the following day, partly mediated by fatigue. Treatment of sleep symptoms would benefit affect in clinical care and beyond.

Toward evidence-based medical statistics: a Bayesian analysis of double-blind placebo-controlled antidepressant trials in the treatment of anxiety disorders

The Food and Drug Administration (FDA) uses a p < 0.05 null-hypothesis significance testing framework to evaluate "substantial evidence" for drug efficacy. This framework only allows dichotomous conclusions and does not quantify the strength of evidence supporting efficacy. The efficacy of FDA-approved antidepressants for the treatment of anxiety disorders was re-evaluated in a Bayesian framework that quantifies the strength of the evidence. Data from 58 double-blind placebo-controlled trials were retrieved from the FDA for the second-generation antidepressants for the treatment of anxiety disorders. Bayes factors (BFs) were calculated for all treatment arms compared to placebo and were compared with the corresponding p-values and the FDA conclusion categories. BFs ranged from 0.07 to 131,400, indicating a range of no support of evidence to strong evidence for the efficacy. Results also indicate a varying strength of evidence between the trials with p < 0.05. In sum, there were large differences in BFs across trials. Among trials providing "substantial evidence" according to the FDA, only 27 out of 59 dose groups obtained strong support for efficacy according to the typically used cutoff of BF ≥ 20. The Bayesian framework can provide valuable information on the strength of the evidence for drug efficacy. Copyright © 2016 John Wiley & Sons, Ltd.

Cross-national epidemiology of panic disorder and panic attacks in the world mental health surveys

CONTEXT

The scarcity of cross-national reports and the changes in Diagnostic and Statistical Manual version 5 (DSM-5) regarding panic disorder (PD) and panic attacks (PAs) call for new epidemiological data on PD and PAs and its subtypes in the general population.

OBJECTIVE

To present representative data about the cross-national epidemiology of PD and PAs in accordance with DSM-5 definitions.

DESIGN AND SETTING

Nationally representative cross-sectional surveys using the World Health Organization Composite International Diagnostic Interview version 3.0.

PARTICIPANTS

Respondents (n = 142,949) from 25 high, middle, and lower-middle income countries across the world aged 18 years or older.

MAIN OUTCOME MEASURES

PD and presence of single and recurrent PAs.

RESULTS

Lifetime prevalence of PAs was 13.2% (SE 0.1%). Among persons that ever had a PA, the majority had recurrent PAs (66.5%; SE 0.5%), while only 12.8% fulfilled DSM-5 criteria for PD. Recurrent PAs were associated with a subsequent onset of a variety of mental disorders (OR 2.0; 95% CI 1.8-2.2) and their course (OR 1.3; 95% CI 1.2-2.4) whereas single PAs were not (OR 1.1; 95% CI 0.9-1.3 and OR 0.7; 95% CI 0.6-0.8). Cross-national lifetime prevalence estimates were 1.7% (SE 0.0%) for PD with a median age of onset of 32 (IQR 20-47). Some 80.4% of persons with lifetime PD had a lifetime comorbid mental disorder.

CONCLUSIONS

We extended previous epidemiological data to a cross-national context. The presence of recurrent PAs in particular is associated with subsequent onset and course of mental disorders beyond agoraphobia and PD, and might serve as a generic risk marker for psychopathology.

Lower Sensitivity to Happy and Angry Facial Emotions in Young Adults with Psychiatric Problems

Many psychiatric problem domains have been associated with emotion-specific biases or general deficiencies in facial emotion identification. However, both within and between psychiatric problem domains, large variability exists in the types of emotion identification problems that were reported. Moreover, since the domain-specificity of the findings was often not addressed, it remains unclear whether patterns found for specific problem domains can be better explained by co-occurrence of other psychiatric problems or by more generic characteristics of psychopathology, for example, problem severity. In this study, we aimed to investigate associations between emotion identification biases and five psychiatric problem domains, and to determine the domain-specificity of these biases. Data were collected as part of the ‘No Fun No Glory’ study and involved 2,577 young adults. The study participants completed a dynamic facial emotion identification task involving happy, sad, angry, and fearful faces, and filled in the Adult Self-Report Questionnaire, of which we used the scales depressive problems, anxiety problems, avoidance problems, Attention-Deficit Hyperactivity Disorder (ADHD) problems and antisocial problems. Our results suggest that participants with antisocial problems were significantly less sensitive to happy facial emotions, participants with ADHD problems were less sensitive to angry emotions, and participants with avoidance problems were less sensitive to both angry and happy emotions. These effects could not be fully explained by co-occurring psychiatric problems. Whereas this seems to indicate domain-specificity, inspection of the overall pattern of effect sizes regardless of statistical significance reveals generic patterns as well, in that for all psychiatric problem domains the effect sizes for happy and angry emotions were larger than the effect sizes for sad and fearful emotions. As happy and angry emotions are strongly associated with approach and avoidance mechanisms in social interaction, these mechanisms may hold the key to understanding the associations between facial emotion identification and a wide range of psychiatric problems.

Bias in the reporting of harms in clinical trials of second-generation antidepressants for depression and anxiety: A meta-analysis

Previous research has shown that reporting bias has inflated the apparent efficacy of antidepressants. We investigated whether apparent safety was also affected. We included 133 trials, involving 31,296 patients, of second-generation antidepressants for the treatment of major depressive disorder (MDD) or anxiety disorders, obtained from Food and Drug Administration (FDA) reviews. We extracted data on overall discontinuation, discontinuation due to adverse events, and serious adverse events (SAEs). Meta-analysis was used to compare discontinuation rates between FDA reviews and matching journal articles, while SAEs were compared qualitatively. The odds ratio for overall discontinuation, comparing drug to placebo, was 1.0 for both sources, while that for discontinuation due to adverse events was 2.4 for both sources. Seventy-seven of 97 (79%) journal articles provided incomplete information on SAEs; sixty-one (63%) articles made no mention of SAEs at all. Of 21 articles which could be compared to the FDA, only 6 (29%) had full reporting without discrepancies. Nine (43%) articles reported a discrepant number of SAEs. Descriptions were absent or discrepant in 6 (29%) additional articles, even for important SAEs such as suicide attempts. In conclusion, reporting bias has not affected average discontinuation rates over trials. However, SAE reporting is not only very poor, with over half of articles failing to discuss SAEs altogether, but discrepancies between the FDA and articles were common and often led to a more favorable drug-placebo comparison. These findings suggest that journal articles are an unreliable source of data on SAEs in antidepressant trials.

Poor guideline adherence in the initiation of antidepressant treatment in children and adolescents in the Netherlands: choice of antidepressant and dose

The Dutch guideline for the treatment of depression in young people recommends initiating antidepressant treatment with fluoxetine, as the evidence for its efficacy is strongest and the risk of suicidality may be lower than with other antidepressants. Furthermore, low starting doses are recommended. We aimed to determine whether antidepressant prescriptions are in accord with guidelines. A cohort of young people aged between 6 and 17 at the time of antidepressant initiation was selected from IABD, a Dutch pharmacy prescription database. The percentage of prescriptions for each antidepressant was determined. Starting and maintenance doses were determined and compared with recommendations for citalopram, fluoxetine, fluvoxamine, and sertraline. During the study period, 2942 patients initiated antidepressant treatment. The proportion of these young people who were prescribed fluoxetine increased from 10.1 % in 1994-2003 to 19.7 % in 2010-2014. However, the most commonly prescribed antidepressants were paroxetine in 1994-2003 and citalopram in 2004-2014. The median starting and maintenance doses were ≤0.5 DDD/day for tricyclic antidepressants and 0.5-1 DDD/day for SSRIs and other antidepressants. Starting doses were guideline-concordant 58 % of the time for children, 31 % for preteens, and 16 % for teens. Sixty percent of teens were prescribed an adult starting dose. In conclusion, guideline adherence was poor. Physicians preferred citalopram over fluoxetine, in contrast to the recommendations. Furthermore, although children were prescribed a low starting dose relatively frequently, teens were often prescribed an adult starting dose. These results suggest that dedicated effort may be necessary to improve guideline adherence.

Association Between Chronic Physical Conditions and the Effectiveness of Collaborative Care for Depression: An Individual Participant Data Meta-analysis

IMPORTANCE

Collaborative care is an intensive care model involving several health care professionals working together, typically a physician, a case manager, and a mental health professional. Meta-analyses of aggregate data have shown that collaborative care is particularly effective in people with depression and comorbid chronic physical conditions. However, only participant-level analyses can rigorously test whether the treatment effect is influenced by participant characteristics, such as chronic physical conditions.

OBJECTIVE

To assess whether the effectiveness of collaborative care for depression is moderated by the presence, type, and number of chronic physical conditions.

DATA SOURCES

Data were obtained from MEDLINE, EMBASE, PubMed, PsycINFO, CINAHL Complete, and Cochrane Central Register of Controlled Trials, and references from relevant systematic reviews. The search and collection of eligible studies was ongoing until May 22, 2015.

STUDY SELECTION

This was an update to a previous meta-analysis. Two independent reviewers were involved in the study selection process. Randomized clinical trials that compared the effectiveness of collaborative care with usual care in adults with depression and reported measured changes in depression severity symptoms at 4 to 6 months after randomization were included in the analysis. Key search terms included depression, dysthymia, anxiety, panic, phobia, obsession, compulsion, posttraumatic, care management, case management, collaborative care, enhanced care, and managed care.

DATA EXTRACTION AND SYNTHESIS

Individual participant data on baseline demographics and chronic physical conditions as well as baseline and follow-up depression severity symptoms were requested from authors of the eligible studies. One-step meta-analysis of individual participant data using appropriate mixed-effects models was performed.

MAIN OUTCOMES AND MEASURES

Continuous outcomes of depression severity symptoms measured using self-reported or observer-rated measures.

RESULTS

Data sets from 31 randomized clinical trials including 36 independent comparisons (N = 10 962 participants) were analyzed. Individual participant data analyses found no significant interaction effects, indicating that the presence (interaction coefficient, 0.02 [95% CI, -0.10 to 0.13]), numbers (interaction coefficient, 0.01 [95% CI, -0.01 to 0.02]), and types of chronic physical conditions do not influence the treatment effect.

CONCLUSIONS AND RELEVANCE

There is evidence that collaborative care is effective for people with depression alone and also for people with depression and chronic physical conditions. Existing guidance that recommends limiting collaborative care to people with depression and physical comorbidities is not supported by this individual participant data meta-analysis.

Temporal dynamics of physical activity and affect in depressed and nondepressed individuals

OBJECTIVE

The association between physical activity and affect found in longitudinal observational studies is generally small to moderate. It is unknown how this association generalizes to individuals. The aim of the present study was to investigate interindividual differences in the bidirectional dynamic relationship between physical activity and affect, in depressed and nondepressed individuals, using time-series analysis.

METHOD

A pair-matched sample of 10 depressed and 10 nondepressed participants (mean age = 36.6, SD = 8.9, 30% males) wore accelerometers and completed electronic questionnaires 3 times a day for 30 days. Physical activity was operationalized as the total energy expenditure (EE) per day segment (i.e., 6 hr). The multivariate time series (T = 90) of every individual were analyzed using vector autoregressive modeling (VAR), with the aim to assess direct as well as lagged (i.e., over 1 day) effects of EE on positive and negative affect, and vice versa.

RESULTS

Large interindividual differences in the strength, direction and temporal aspects of the relationship between physical activity and positive and negative affect were observed. An exception was the direct (but not the lagged) effect of physical activity on positive affect, which was positive in nearly all individuals.

CONCLUSION

This study showed that the association between physical activity and affect varied considerably across individuals. Thus, while at the group level the effect of physical activity on affect may be small, in some individuals the effect may be clinically relevant.

Age of Onset and Lifetime Projected Risk of Psychotic Experiences: Cross-National Data From the World Mental Health Survey

BACKGROUND

Given the early age of onset (AOO) of psychotic disorders, it has been assumed that psychotic experiences (PEs) would have a similar early AOO. The aims of this study were to describe (a) the AOO distribution of PEs, (b) the projected lifetime risk of PEs, and (c) the associations of PE AOO with selected PE features.

METHODS

Data came from the WHO World Mental Health (WMH) surveys. A total of 31 261 adult respondents across 18 countries were assessed for lifetime prevalence of PE. Projected lifetime risk (at age 75 years) was estimated using a 2-part actuarial method. AOO distributions were described for the observed and projected estimates. We examined associations of AOO with PE type metric and annualized PE frequency.

RESULTS

Projected lifetime risk for PEs was 7.8% (SE = 0.3), slightly higher than lifetime prevalence (5.8%, SE = 0.2). The median (interquartile range; IQR) AOO based on projected lifetime estimates was 26 (17-41) years, indicating that PEs commence across a wide age range. The AOO distributions for PEs did not differ by sex. Early AOO was positively associated with number of PE types (F = 14.1, P < .001) but negatively associated with annualized PE frequency rates (F = 8.0, P < .001).

DISCUSSION

While most people with lifetime PEs have first onsets in adolescence or young adulthood, projected estimates indicate that nearly a quarter of first onsets occur after age 40 years. The extent to which late onset PEs are associated with (a) late onset mental disorders or (b) declining cognitive and/or sensory function need further research.

The temporal dynamics of cortisol and affective states in depressed and non-depressed individuals

OBJECTIVES

Cortisol levels have been related to mood disorders at the group level, but not much is known about how cortisol relates to affective states within individuals over time. We examined the temporal dynamics of cortisol and affective states in depressed and non-depressed individuals in daily life. Specifically, we addressed the direction and timing of the effects, as well as individual differences.

METHODS

Thirty depressed and non-depressed participants (aged 20-50 years) filled out questionnaires regarding their affect and sampled saliva three times a day for 30 days in their natural environment. They were pair-matched on age, gender, smoking behavior and body mass index. The multivariate time series (T=90) of every participant were analyzed using vector autoregressive (VAR) modeling to assess lagged effects of cortisol on affect, and vice versa. Contemporaneous effects were assessed using the residuals of the VAR models. Impulse response function analysis was used to examine the timing of effects.

RESULTS

For 29 out of 30 participants, a VAR model could be constructed. A significant relationship between cortisol and positive or negative affect was found for the majority of the participants, but the direction, sign, and timing of the relationship varied among individuals.

CONCLUSION

This approach proves to be a valuable addition to traditional group designs, because our results showed that daily life fluctuations in cortisol can influence affective states, and vice versa, but not in all individuals and in varying ways. Future studies may examine whether these individual differences relate to susceptibility for or progression of mood disorders.

Influence of baseline severity on antidepressant efficacy for anxiety disorders: meta-analysis and meta-regression

BACKGROUND

Antidepressants are established first-line treatments for anxiety disorders, but it is not clear whether they are equally effective across the severity range.

AIMS

To examine the influence of baseline severity of anxiety on antidepressant efficacy for generalised anxiety disorder (GAD), social anxiety disorder (SAD), obsessive-compulsive disorder (OCD), post-traumatic stress disorder (PTSD) and panic disorder.

METHOD

Fifty-six trials of second-generation antidepressants for the short-term treatment of an anxiety disorder were included. Baseline and change scores were extracted for placebo and treatment groups in each trial. Mixed effects meta-regression was used to investigate the effects of treatment group, baseline severity and their interaction.

RESULTS

Increased baseline severity did not predict greater improvement in drug groups compared with placebo groups. Standardised regression coefficients of the interaction term between baseline severity and treatment group were 0.04 (95% CI -0.13 to 0.20, P = 0.65) for GAD, -0.06 (95% CI -0.20 to 0.09, P = 0.43) for SAD, 0.04 (95% CI -0.07 to 0.16, P = 0.46) for OCD, 0.16 (95% CI -0.22 to 0.53, P = 0.37) for PTSD and 0.002 (95% CI -0.10 to 0.10, P = 0.96) for panic disorder. For OCD, baseline severity did predict improvement in both placebo and drug groups equally (β = 0.11, 95% CI 0.05 to 0.17, P = 0.001).

CONCLUSIONS

No relationship between baseline severity and drug-placebo difference was found for anxiety disorders. These results suggest that if the efficacy of antidepressants is considered clinically relevant, they may be prescribed to patients with anxiety regardless of symptom severity.

Gray matter volume and white matter lesions in chronic kidney disease: exploring the association with depressive symptoms

OBJECTIVE

Chronic kidney disease (CKD) is associated with structural brain damage and with a high prevalence of depression. We therefore investigated structural brain alterations in both gray and white matter in CKD patients, focusing on depression-related (frontal-subcortical) regions.

METHOD

This cross-sectional MRI study in 24 CKD patients and 24 age- and sex-matched controls first tested whether CKD was associated with regionally lower gray matter (GM) volumes and more severe white matter lesions (WMLs). In exploratory subanalyses, we examined whether differences were more pronounced in CKD patients with depressive symptoms.

RESULTS

CKD patients showed lower global GM volume (P=.04) and more severe WMLs (P=.04) compared to controls. In addition, we found substantial clusters of lower GM in the bilateral orbitofrontal-cortex for CKD patients, which were however nonsignificant after proper multiple-comparison correction. In exploratory analyses for depressed CKD patients, reduced GM clusters were mainly detected within the frontal lobe. WML severity was unrelated to depression.

CONCLUSION

CKD was characterized by differences in brain structure. Although subthreshold, lower GM volumes were observed in depression-related brain areas and were more pronounced for depressed patients. There is a need for replication in larger and longitudinal studies to investigate whether WMLs and regional GM reductions may render CKD patients more susceptible for depression.

Preserving Subjective Wellbeing in the Face of Psychopathology: Buffering Effects of Personal Strengths and Resources

BACKGROUND

Many studies on resilience have shown that people can succeed in preserving mental health after a traumatic event. Less is known about whether and how people can preserve subjective wellbeing in the presence of psychopathology. We examined to what extent psychopathology can co-exist with acceptable levels of subjective wellbeing and which personal strengths and resources moderate the association between psychopathology and wellbeing.

METHODS

Questionnaire data on wellbeing (Manchester Short Assessment of Quality of Life/Happiness Index), psychological symptoms (Depression Anxiety Stress Scales), and personal strengths and resources (humor, Humor Style questionnaire; empathy, Empathy Quotient questionnaire; social company; religion; daytime activities, Living situation questionnaire) were collected in a population-based internet study (HowNutsAreTheDutch; N = 12,503). Data of the subset of participants who completed the above questionnaires (n = 2411) were used for the present study. Regression analyses were performed to predict wellbeing from symptoms, resources, and their interactions.

RESULTS

Satisfactory levels of wellbeing (happiness score 6 or higher) were found in a substantial proportion of the participants with psychological symptoms (58% and 30% of those with moderate and severe symptom levels, respectively). The association between symptoms and wellbeing was large and negative (-0.67, P < .001), but less so in persons with high levels of self-defeating humor and in those with a partner and/or pet. Several of the personal strengths and resources had a positive main effect on wellbeing, especially self-enhancing humor, having a partner, and daytime activities.

CONCLUSIONS

Cultivating personal strengths and resources, like humor, social/animal company, and daily occupations, may help people preserve acceptable levels of wellbeing despite the presence of symptoms of depression, anxiety, and stress.

Effects of urinary cortisol levels and resting heart rate on the risk for fatal and nonfatal cardiovascular events

BACKGROUND AND AIMS

Higher cortisol levels are associated with cardiovascular mortality in the elderly. It is unclear whether this association also exists in a general population of younger adults and for non-fatal cardiovascular events. Likewise, resting heart rate is associated with cardiovascular mortality, but fewer studies have also considered non-fatal events. The goal of this study was to investigate whether twenty-four-hour urinary cortisol (24-h UFC) levels and resting heart rate (RHR) predict major adverse fatal and non-fatal cardiovascular events (MACE) in the general population.

METHODS

We used data from a subcohort of the PREVEND study, a prospective general population based cohort study with a follow-up of 6.4 years for 24-h UFC and 10.6 years for RHR. Participants were 3432 adults (mean age 49 years, range 28-75). 24-h UFC was collected and measured by liquid chromatography-tandem mass spectrometry. RHR was measured at baseline in a supine position for 10 min with the Dinamap XL Model 9300. Information about cardiovascular events and mortality was obtained from the Dutch national registry of hospital discharge diagnoses and the municipal register respectively.

RESULTS

24-h UFC did not significantly increase the hazard of MACE (hazard ratio = 0.999, 95% confidence interval = 0.993-1.006, p = 0.814). RHR increased the risk for MACE with 17% per 10 extra heart beats per minute (hazard ratio = 1.016, 95% confidence interval = 1.001-1.031, p = 0.036) after adjustment for conventional risk factors.

CONCLUSIONS

In contrast to 24-h UFC, RHR is a risk marker for MACE in the general population.

A bifactor model of the Beck Depression Inventory and its association with medical prognosis after myocardial infarction

OBJECTIVES

Evidence suggests that depression is associated with adverse outcomes in patients with myocardial infarction (MI). Some of the symptoms of depression may also be symptoms of somatic illness and these may confound the association between depression and prognosis. We investigated whether depression following MI is associated with medical prognosis independent of these somatic symptoms.

METHOD

The database of an individual patient data meta-analysis was used. Endpoints were all-cause mortality and cardiovascular events. Nine studies were included. Bifactor factor analysis included 13,100 participants and 7,595 participants were included in survival models. Dimensions were generated from the Beck Depression Inventory using factor analyses. The prognostic association was assessed using mixed-effects Cox regression analysis.

RESULTS

A bifactor model, consisting of a general factor and 2 general depression-free subgroup factors (a somatic/affective and a cognitive/affective), provided the best fit. There was a significant association between the general depression factor and all-cause mortality (hazard ratio [HR] = 1.25; 95% confidence interval [CI] [1.17, 1.34], p < .001) and cardiovascular events (HR = 1.18; 95% CI [1.13, 1.23], p < .001). After adjustment for demographics, measures of cardiac disease severity, and health-related variables, the association between the general depression factor and all-cause mortality (HR = 1.14; 95% CI [1.04, 1.25], p = .003) and cardiovascular events (HR = 1.16; 95% CI [1.10, 1.23], p = .014) attenuated. Additionally, the general depression-free somatic/affective factor was significantly associated with the endpoints, while the general depression-free cognitive/affective was not.

CONCLUSIONS

A general depression factor is associated with adverse medical prognosis following MI independent of somatic/affective symptoms that may be partly attributable to somatic illness. (PsycINFO Database Record

PSYCHIATRIC COMORBIDITY DOES NOT ONLY DEPEND ON DIAGNOSTIC THRESHOLDS: AN ILLUSTRATION WITH MAJOR DEPRESSIVE DISORDER AND GENERALIZED ANXIETY DISORDER

BACKGROUND

High rates of psychiatric comorbidity are subject of debate: To what extent do they depend on classification choices such as diagnostic thresholds? This paper investigates the influence of different thresholds on rates of comorbidity between major depressive disorder (MDD) and generalized anxiety disorder (GAD).

METHODS

Point prevalence of comorbidity between MDD and GAD was measured in 74,092 subjects from the general population (LifeLines) according to Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR) criteria. Comorbidity rates were compared for different thresholds by varying the number of necessary criteria from ≥ 1 to all nine symptoms for MDD, and from ≥ 1 to all seven symptoms for GAD.

RESULTS

According to DSM thresholds, 0.86% had MDD only, 2.96% GAD only, and 1.14% both MDD and GAD (odds ratio (OR) 42.6). Lower thresholds for MDD led to higher rates of comorbidity (1.44% for ≥ 4 of nine MDD symptoms, OR 34.4), whereas lower thresholds for GAD hardly influenced comorbidity (1.16% for ≥ 3 of seven GAD symptoms, OR 38.8). Specific patterns in the distribution of symptoms within the population explained this finding: 37.3% of subjects with core criteria of MDD and GAD reported subthreshold MDD symptoms, whereas only 7.6% reported subthreshold GAD symptoms.

CONCLUSIONS

Lower thresholds for MDD increased comorbidity with GAD, but not vice versa, owing to specific symptom patterns in the population. Generally, comorbidity rates result from both empirical symptom distributions and classification choices and cannot be reduced to either of these exclusively. This insight invites further research into the formation of disease concepts that allow for reliable predictions and targeted therapeutic interventions.

Association of Depressive and Anxiety Disorders With Diagnosed Versus Undiagnosed Diabetes: An Epidemiological Study of 90,686 Participants

OBJECTIVE

To compare the odds of depressive and anxiety disorders for participants with diagnosed diabetes, participants with diabetes but unaware of this, and participants without diabetes. Such knowledge might improve etiological insight into psychopathology in diabetes.

METHODS

Data of 90,686 participants (mean age = 45 years; 59% female) from the LifeLines cohort was used. Depressive and anxiety disorders were assessed by the Mini-International Neuropsychiatric Interview. The odds of depression and anxiety were assessed for three groups: a) diagnosed diabetes, diabetes medication use and/or self-reported "diabetes"; b) undiagnosed diabetes, fasting blood glucose ≥7.0 mmol/l, but no diabetes medication use and self-reported "no diabetes"; and c) no diabetes, fasting blood glucose <7.0 mmol/l and self-reported "no diabetes." Logistic regression was performed to compare the odds of depression and anxiety in these groups, adjusting for age, sex, diabetes-related diseases, comorbid depressive or anxiety disorders, and glycosylated hemoglobin.

RESULTS

A total of 3002 (3.3%) participants were diagnosed as having depression and 9018 (9.9%) as having anxiety; 1781 (2.0%) had diagnosed and 786 (0.9%) had undiagnosed diabetes. Both diagnosed (odds ratio [OR] = 1.4:1.1-1.8, p = .006) and undiagnosed (OR = 1.8:1.3-2.6, p = .001) diabetes were independently associated with depression. The odds of depression did not differ between diagnosed and undiagnosed diabetes (OR = 0.7, p = .17). Diagnosed diabetes was independently associated with anxiety (OR = 1.4:1.2-1.7, p < .001), but undiagnosed diabetes was not (OR = 0.8:0.6-1.1, p = .20). The odds of anxiety were significantly higher in diagnosed compared with undiagnosed diabetes (1.68:1.23-2.31, p = .001).

CONCLUSIONS

Depression was more prevalent in participants with diagnosed and undiagnosed diabetes, whereas anxiety was more prevalent only in participants who were aware of their diabetes. Longitudinal research is needed to assess the causal pathways of these associations.