Why would associations between cardiometabolic risk factors and depressive symptoms be linear?

In medical science, researchers mostly use the linear model to determine associations among variables, while in reality many associations are likely to be non-linear. Recent advances have shown that associations may be regarded as parts of complex, dynamic systems for which the linear model does not yield valid results. Using as an example the interdepencies between organisms in a small ecosystem, we present the work of Sugihara et al. in Science 2012, 338:496-500 who developed an alternative non-parametric method to determine the true associations among variables in a complex dynamic system. In this context, we discuss the work of Jani et al. recently published in BMC Cardiovascular Disorders, describing a non-linear, J-shaped curve between a series of cardiometabolic risk factors and depression. Although the exact meaning of these findings may not yet be clear, they represent a first step in a different way of thinking about the relationships among medical variables, namely going beyond the linear model

A comparison of DSM-5 and DSM-IV agoraphobia in the World Mental Health Surveys

BACKGROUND: The Diagnostic and Statistical Manual of Mental Disorders, version 5 (DSM-5) definition of agoraphobia (AG) as an independent diagnostic entity makes it timely to re-examine the epidemiology of AG. Study objective was to present representative data on the characteristics of individuals who meet DSM-IV criteria for AG (AG without a history of panic disorder [PD] and PD with AG) but not DSM-5 criteria, DSM-5 but not DSM-IV criteria, or both sets of criteria.METHODS: Population-based surveys from the World Mental Health Survey Initiative including adult respondents (n = 136,357) from 27 countries across the world. The Composite International Diagnostic Interview was used to assess AG and other disorders.RESULTS: Lifetime and 12-month prevalence estimates of DSM-5 AG (1.5% and 1.0%) were comparable to DSM-IV (1.4% and 0.9%). Of respondents meeting criteria in either system, 57.1% met criteria in both, while 24.2% met criteria for DSM-5 only and 18.8% for DSM-IV only. Severe role impairment due to AG was reported by a lower proportion of respondents who met criteria only for DSM-IV AG (30.4%) than those with both DSM-5 and DSM-IV AG (44.0%; χ 21  = 4.7; P = 0.031). The proportion of cases with any comorbidity was lower among respondents who met criteria only for DSM-IV AG (78.7%) than those who met both sets (92.9%; χ 21 = 14.5; P &lt; 0.001).CONCLUSIONS: This first large survey shows that, compared to the DSM-IV, the DSM-5 identifies a substantial group of new cases with AG, while the prevalence rate remains stable at 1.5%. Severity and comorbidity are higher in individuals meeting DSM-5 AG criteria compared with individuals meeting DSM-IV AG criteria only.</p

The heart of the matter:in search of causal effects of depression on somatic diseases

The question of whether depression is a causal factor in somatic diseases remains unanswered despite decades of research. In an extensive umbrella review of systematic reviews and meta-analyses, Machado et al. (BMC Medicine 16:112, 2018) found significant associations between depression and all-cause and cause-specific mortality. However, as the authors clearly argued, these results do not prove causation. The next logical step is to study the potential effect of depression and other mental disorders by placing emphasis on temporality (associations over time) and specificity (unique associations) of associations between a comprehensive set of mental disorders and somatic diseases. A data-driven approach in large samples could uncover disease development trajectories to provide a route for researchers and clinicians to improve medical outcomes in vulnerable patient groups

Positive affect and functional somatic symptoms in young adults

Background Functional Somatic Symptoms (FSS) are symptoms for which an underlying pathology cannot be found. High negative affect (NA) has been linked to the etiology of FSS, but little is known about the role of Positive Affect (PA). Objective: The aim of this study was to test if PA is related to current and future lower levels of FSS. We also examined the interactions between PA and NA, and PA and sex on FSS. Method: Data from the Dutch Tracking Adolescents' Individual Lives Survey (TRAILS) cohort were used (N = 1247 cases, 60% females, mean age T5 = 22.2, T6 = 25.6). PA was measured with the PANAS schedule and FSS with the Adult Self Report questionnaire (ASR). A Principal Component Analysis (PCA) was performed on the physical complaints subscale of the ASR. Regression analyses with bootstrapping were performed to assess the associations and interactions. Results: PA had a significant negative association with current FSS when adjusted for NA, age, sex and socioeconomic status (B = 0.004; BCa 95% CI = [ -0.006; -0.002]), but the association was not significant longitudinally. No interactions were found. In secondary analysis, PA was significantly related to the component "General Physical Symptoms" (B = -0.019; BCa 95% CI = [ -0.0028; -0.011]) but not to the component "Gastrointestinal Symptoms" (B = -0.008; BCa 95% CI = [ -0.016;0.001]) in the cross-sectional analysis. Conclusion: In conclusion, high PA was significantly related to current lower levels of FSS, but the effect was small. Further research on individual variations in affect is needed to obtain more insight in their contribution to FSS

Anxiety and Risk of Incident Coronary Heart Disease:A Meta-Analysis

ObjectivesThe purpose of this study was to assess the association between anxiety and risk of coronary heart disease (CHD).BackgroundLess research has focused on the association of anxiety with incident CHD in contrast to other negative emotions, such as depression.MethodsA meta-analysis of references derived from PubMed, EMBASE, and PsycINFO (1980 to May 2009) was performed without language restrictions. End points were cardiac death, myocardial infarction (MI), and cardiac events. The authors selected prospective studies of (nonpsychiatric) cohorts of initially healthy persons in which anxiety was assessed at baseline.ResultsTwenty studies reporting on incident CHD comprised 249,846 persons with a mean follow-up period of 11.2 years. Anxious persons were at risk of CHD (hazard ratio [HR] random: 1.26; 95% confidence interval [CI]: 1.15 to 1.38; p < 0.0001) and cardiac death (HR: 1.48; 95% CI: 1.14 to 1.92; p = 0.003), independent of demographic variables, biological risk factors, and health behaviors. There was a nonsignificant trend for an association between anxiety and nonfatal MI (HR: 1.43; 95% CI: 0.85 to 2.40; p = 0.180). Subgroup analyses did not show any significant differences regarding study characteristics, with significant associations for different types of anxiety, short- and long-term follow-up, and both men and women.ConclusionsAnxiety seemed to be an independent risk factor for incident CHD and cardiac mortality. Future research should examine the association between anxiety and CHD with valid and reliable anxiety measures and focus on the mechanisms through which anxiety might affect CHD

The bidirectional association between sleep problems and anxiety symptoms in adolescents:a TRAILS report

Background: Previous studies have suggested a bidirectional association between sleep problems and anxiety symptoms in adolescents. These studies used methods that do not separate between-person effects from within-person effects, and therefore their conclusions may not pertain to within-person mutual influences of sleep and anxiety. We examined bidirectional associations between sleep problems and anxiety during adolescence and young adulthood while differentiating between person effects from within-person effects. Methods: Data came from the Dutch TRacking Adolescents' Individual Lives Survey (TRAILS), a prospective cohort study including six waves of data spanning 15 years. Young adolescents (N = 2230, mean age at baseline 11.1 years) were followed every 2–3 years until young adulthood (mean age 25.6 years). Sleep problems and anxiety symptoms were measured by the Youth Self-Report, Adult Self-Report and Nottingham Health Profile. Temporal associations between sleep and anxiety were investigated using the random intercept cross-lagged panel model. Results: Across individuals, sleep problems were significantly associated with (β = 0.60, p < 0.001). At the within-person level, there were significant cross–sectional associations between sleep problems and anxiety symptoms at all waves (β = 0.12–0.34, p < 0.001). In addition, poor sleep predicted greater anxiety symptoms between the first and second, and between the third and fourth assessment wave. The reverse association was not statistically significant. Conclusions: Within-person associations between sleep problems and anxiety are considerably weaker than between-person associations. Yet, our findings tentatively suggest that poor sleep, especially during early and mid-adolescence, may precede anxiety symptoms, and that anxiety might be prevented by alleviating sleep problems in young adolescents

Seasonality of mood and affect in a large general population sample

Mood and behaviour are thought to be under considerable influence of the seasons, but evidence is not unequivocal. The purpose of this study was to investigate whether mood and affect are related to the seasons, and what is the role of neuroticism in this association. In a national internet-based crowdsourcing project in the Dutch general population, individuals were invited to assess themselves on several domains of mental health. ANCOVA was used to test for differences between the seasons in mean scores on the Positive and Negative Affect Schedule (PANAS) and Quick Inventory of Depressive Symptomatology (QIDS). Within-subject seasonal differences were tested as well, in a subgroup that completed the PANAS twice. The role of neuroticism as a potential moderator of seasonality was examined. Participants (n = 5,282) scored significantly higher on positive affect (PANAS) and lower on depressive symptoms (QIDS) in spring compared to summer, autumn and winter. They also scored significantly lower on negative affect in spring compared to autumn. Effect sizes were small or very small. Neuroticism moderated the effect of the seasons, with only participants higher on neuroticism showing seasonality. There was no within-subject seasonal effect for participants who completed the questionnaires twice (n = 503), nor was neuroticism a significant moderator of this within-subjects effect. The findings of this study in a general population sample participating in an online crowdsourcing study do not support the widespread belief that seasons influence mood to a great extent. For, as far as the seasons did influence mood, this only applied to highly neurotic participants and not to low-neurotic participants. The underlying mechanism of cognitive attribution may explain the perceived relation between seasonality and neuroticism

Initial severity and antidepressant efficacy for anxiety disorders, obsessive-compulsive disorder, and posttraumatic stress disorder:An individual patient data meta-analysis

Background: It has been suggested that antidepressant benefits are smaller for mild than severe depression. Because antidepressants are also used for anxiety disorders, obsessive-compulsive disorder (OCD), and posttraumatic stress disorder (PTSD), we examined the influence of severity for these disorders. Methods: We used individual patient data of eight trials (3,430 participants) for generalized anxiety disorder (GAD); four trials (1,195 participants) for social anxiety disorder (SAD); four trials (1,132 participants) for OCD; three trials (1,071 participants) for PTSD; and 10 trials (2,151 participants) for panic disorder (PD). Mixed-effects models were used to investigate an interaction between severity and treatment group. Results: For GAD and PD, severity moderated antidepressant efficacy. The antidepressant-placebo difference was 1.4 (95% CI: 0.4-2.5; SMD: 0.21) Hamilton Anxiety Rating Scale (HAM-A) points for participants with mild GAD (baseline HAM-A=10), increasing to 4.0 (3.4-4.6; SMD: 0.45) or greater for severely ill participants (HAM-A >= 30). For PD, the difference was 0.4 (0.3-0.6) panic attacks/2weeks for participants with 10 panic attacks/2weeks at baseline, increasing to 4.7 (3.0-6.4) for participants with 40. For SAD, OCD, and PTSD, no interaction was found. Across severity levels, the differences were 16.1 (12.9-19.3; SMD: 0.59) Liebowitz Social Anxiety Scale points, 3.4 (2.5-4.4, SMD: 0.39) Yale-Brown Obsessive-Compulsive Scale points, and 10.3 (6.9-13.6; SMD: 0.41) Clinician-Administered PTSD Scale points. Conclusions: Antidepressants are equally effective across severity levels for SAD, OCD, and PTSD. For GAD and PD, however, benefits are small at low severity, and the benefit-risk ratio may be unfavorable for these patients

Commentary:The evidence base regarding the long-term effects of childhood mental disorder treatments needs to be strengthened – reply to Dekkers et al. (2023)

In their reply to our editorial (Journal of Child Psychology and Psychiatry, 2023, 64, 464), Dekkers et al. (Journal of Child Psychology and Psychiatry, 2023, 64, 470) argue that treatment is the best choice for children with mental disorders because there is ‘sound evidence’ that interventions are effective, also in the long term. We agree that there is sound evidence for treatment effectiveness in the short-term and there is some evidence for longer-term effects of certain specific treatments, such as behavioral parent training in children with behavioral disorders, as acknowledged in our editorial. However, we strongly disagree that there is sound evidence for long-term effectiveness.</p