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

Single-Subject Research in Psychiatry:Facts and Fictions

Scientific evidence in the field of psychiatry is mainly derived from group-based ("nomothetic") studies that yield group-aggregated results, while often the need is to answer questions that apply to individuals. Particularly in the presence of great inter-individual differences and temporal complexities, information at the individual-person level may be valuable for personalized treatment decisions, individual predictions and diagnostics. The single-subject study design can be used to make inferences about individual persons. Yet, the single-subject study is not often used in the field of psychiatry. We believe that this is because of a lack of awareness of its value rather than a lack of usefulness or feasibility. In the present paper, we aimed to resolve some common misconceptions and beliefs about single-subject studies by discussing some commonly heard "facts and fictions." We also discuss some situations in which the single-subject study is more or less appropriate, and the potential of combining single-subject and group-based study designs into one study. While not intending to plea for single-subject studies at the expense of group-based studies, we hope to increase awareness of the value of single-subject research by informing the reader about several aspects of this design, resolving misunderstanding, and providing references for further reading

A qualitative approach to guide choices for designing a diary study

Background: Electronic diaries are increasingly used in diverse disciplines to collect momentary data on experienced feelings, cognitions, behavior and social context in real life situations. Choices to be made for an effective and feasible design are however a challenge. Careful and detailed documentation of argumentation of choosing a particular design, as well as general guidelines on how to design such studies are largely lacking in scientific papers. This qualitative study provides a systematic overview of arguments for choosing a specific diary study design (e.g. time frame) in order to optimize future design decisions. Methods: During the first data assessment round, 47 researchers experienced in diary research from twelve different countries participated. They gave a description of and arguments for choosing their diary design (i.e., study duration, measurement frequency, random or fixed assessment, momentary or retrospective assessment, allowed delay to respond to the beep). During the second round, 38 participants (81%) rated the importance of the different themes identified during the first assessment round for the different diary design topics. Results: The rationales for diary design choices reported during the first round were mostly strongly related to the research question. The rationales were categorized into four overarching themes: nature of the variables, reliability, feasibility, and statistics. During the second round, all overarching themes were considered important for all diary design topics. Conclusions: We conclude that no golden standard for the optimal design of a diary study exists since the design depends heavily upon the research question of the study. The findings of the current study are helpful to explicate and guide the specific choices that have to be made when designing a diary study

Using bundle embeddings to predict daily cortisol levels in human subjects

BACKGROUND: Many biological variables sampled from human subjects show a diurnal pattern, which poses special demands on the techniques used to analyze such data. Furthermore, most biological variables belong to nonlinear dynamical systems, which may make linear statistical techniques less suitable to analyze their dynamics. The current study investigates the usefulness of two analysis techniques based on nonlinear lagged vector embeddings: sequentially weighted global linear maps (SMAP), and bundle embeddings. METHODS: Time series of urinary cortisol were collected in 10 participants, in the morning ('night' measurement) and the evening ('day' measurement), resulting in 126 consecutive measurements. These time series were used to create lagged vector embeddings, which were split into 'night' and 'day' bundle embeddings. In addition, embeddings were created based on time series that were corrected for the average time-of-day (TOD) values. SMAP was used to predict future values of cortisol in these embeddings. Global (linear) and local (non-linear) predictions were compared for each embedding. Bootstrapping was used to obtain confidence intervals for the model parameters and the prediction error. RESULTS: The best cortisol predictions were found for the night bundle embeddings, followed by the full embeddings and the time-of-day corrected embeddings. The poorest predictions were found for the day bundle embeddings. The night bundle embeddings, the full embeddings and the TOD-corrected embeddings all showed low dimensions, indicating the absence of dynamical processes spanning more than one day. The dimensions of the day bundles were higher, indicating the presence of processes spanning more than one day, or a higher amount of noise. In the full embeddings, local models gave the best predictions, whereas in the bundles the best predictions were obtained from global models, indicating potential nonlinearity in the former but not the latter. CONCLUSIONS: Using a bundling approach on time series of cortisol may reveal differences between the predictions of night and day cortisol that are difficult to find with conventional time-series methods. Combination of this approach with SMAP may especially be useful when analyzing time-series data with periodic components

Daily fluctuations of negative affect are only weakly associated with tremor symptoms in functional and organic tremor patients

BACKGROUND: There is a long-standing research history on the presumed psychological origin of functional movement disorders. Most studies do not address the heterogeneity in functional movement disorders and do not distinguish between risk factors, causes and consequences. We studied the associations between negative affect and objective as well as subjective symptom levels in patients with functional and organic tremor. METHODS: Thirty-three patients with a functional (14) or organic tremor (19) completed a web-based diary on subjective symptom burden and negative affect, five times a day for 30 days (total number of observations = 4759). During the same period, the participants wore an accelerometer to objectively record tremor. Vector autoregressive modelling was used to determine the time-lagged and contemporaneous associations between negative affect and objective/subjective tremor symptoms, both on an individual and a group level. RESULTS: In contrast to previous literature, patients with a functional or organic tremor showed a weak contemporaneous association between negative affect and objective/subjective tremor symptoms (on average r = 0.038 and 0.174 respectively). Time-lagged associations between negative affect and objective/subjective tremor symptoms were mixed in effect and direction and only present in a subset of patients, with no differences between patients with functional or organic tremor. CONCLUSIONS: Negative affect is only weakly associated with objective/subjective tremor symptoms, both on the contemporaneous and time-lagged associations, and these associations were mainly similar between patients with functional or organic tremor. These results argue against a strong influence of daily stress on tremor symptoms in patients with a functional or organic tremor

Hypermethylation of CTDSPL2 prior to necrotizing enterocolitis onset

Background: Necrotizing enterocolitis (NEC) is the most common gastrointestinal emergency in preterm infants. Epigenetic changes in DNA methylation may be present prior to NEC onset. Methods: 24 preterm infants with NEC and 45 matched controls were included. Human DNA was isolated from stool samples and methylation of CTDSPL2, HERC1, NXPE3 and PTGDR was measured using pyrosequencing. Results: CTDSPL2 displayed a higher DNA methylation of 51% compared with 17% in controls, prior to NEC onset (p = 0.047). Discussion: Noninvasive measurement of methylation in stool allows for comparison with healthy preterm controls. This potentially allows future biomarker or risk predictor use. The effect of CTDSPL2 hypermethylation on gene expression remains unclear. Plain language summary What is this article about? Necrotizing enterocolitis (NEC) is a common emergency condition affecting the gastrointestinal system of preterm infants. Epigenetic changes in DNA methylation may be present in infants before the onset of NEC. DNA methylation is a natural process that can help turn genes on or off, thereby affecting their function. This study focused on measuring the amount of DNA methylation in certain genes in preterm infants who developed NEC. What were the results? This study included 24 preterm infants with NEC and 45 matched healthy controls. The researchers isolated human DNA from stool samples, and the amount of DNA methylation of four specific genes was measured. They found that one of the genes, CTDSPL2, had significantly higher DNA methylation in infants who later developed NEC than in healthy infants. What do the results of the study mean? In this study, researchers found that CTDSPL2 showed a higher level of DNA methylation in stool samples of infants who later developed NEC. The effect of this change remains unclear, but may affect the way cells grow and respond to injury or infection, which could contribute to the development of NEC. Measuring DNA methylation in stool samples provides a noninvasive method for identifying DNA methylation changes in preterm infants. Comparing the amount of DNA methylation in healthy infants with that in preterm infants at risk of NEC may help predict the risk of developing NEC. &lt;/sec. Tweetable abstract DNA samples from infants show higher DNA methylation of the marker gene CTDSPL2 prior to necrotizing enterocolitis #NEC onset.</p

Prognostic association of depression following myocardial infarction with mortality and cardiovascular events:A meta-analysis of 25 years of research

AbstractObjectiveA meta-analysis of over 25 years of research into the relationship between post-myocardial infarction (MI) depression and cardiac prognosis was conducted to investigate changes in this association over time and to investigate subgroup effects.MethodA systematic literature search was performed (Medline, Embase and PsycINFO; 1975–2011) without language restrictions. Studies investigating the impact of post-MI depression on cardiovascular outcome, defined as all-cause mortality, cardiac mortality and cardiac events within 24 months after the index MI, were identified. Depression had to be assessed within 3 months after MI using established instruments. Pooled odds ratios (ORs) were calculated using a random effects model.ResultsA total of 29 studies were identified, resulting in 41 comparisons. Follow-up (on average 16 months) was described for 16,889 MI patients. Post-MI depression was associated with an increased risk of all-cause mortality [(OR), 2.25; 95% confidence interval [CI], 1.73–2.93; P<.001], cardiac mortality (OR, 2.71; 95% CI, 1.68–4.36; P<.001) and cardiac events (OR, 1.59; 95% CI, 1.37–1.85; P<.001). ORs proved robust in subgroup analyses but declined over the years for cardiac events.ConclusionsPost-MI depression is associated with a 1.6- to 2.7-fold increased risk of impaired outcomes within 24 months. This association has been relatively stable over the past 25 years

Pulmonary hypertension in extremely preterm infants:a call to standardize echocardiographic screening and follow-up policy

Pulmonary hypertension (PH) is a frequent complication in extremely preterm born infants that seriously affects outcome. We aimed to describe the prevalence of PH in extremely preterm infants and the policy on screening and follow-up in the ten Dutch intensive care units (NICUs). We performed a retrospective cohort study at the University Medical Centre Groningen on infants with gestational age <30 weeks and/or birthweight <1000 g, born between 2012 and 2013. Additionally, we carried out a survey among the Dutch NICUs covering questions on the awareness of PH, the perceived prevalence, and policy regarding screening and following PH in extremely preterm infants. Prevalence of early-onset PH in our study was 26% and 5% for late-onset PH. PH was associated with poor survival and early-onset PH was associated with subsequent development of bronchopulmonary dysplasia (BPD). All the NICUs completed the questionnaire and we found that no standardized policy existed regarding screening and following PH in extremely preterm infants. Conclusion: Despite the frequent occurrence of PH and its clinically important consequences, (inter-)national standardized guidelines regarding screening and following of PH in extremely preterm infants are lacking. Standardizing screening and follow-up will enable early identification of infants with late-onset PH and allow for earlier treatment. Additionally, greater clarity is required regarding the prevalence of early PH as are new preventive treatment strategies to combat BPD. What is known? center dot Pulmonary hypertension (PH) substantially impairs the survival of extremely preterm infants. center dot PH is associated with bronchopulmonary dysplasia (BPD): Early-onset PH predicts the development of BPD. Late-onset PH is prevalent in infants with severe BPD. What is new? center dot Pulmonary hypertension (PH) is prevalent in preterm infants. Its consequences for morbidity and mortality justify a standardized policy aimed at early detection to improve prevention and treatment. center dot No structured policy exists in the Netherlands regarding screening/follow-up for PH in extremely preterm infants

The effects of low-intensity narrow-band blue-light treatment compared to bright white-light treatment in sub-syndromal seasonal affective disorder

Background The discovery of a novel photoreceptor in the retinal ganglion cells with a highest sensitivity of 470-490 nm blue light has led to research on the effects of short-wavelength light in humans. Several studies have explored the efficacy of monochromatic blue or blue-enriched light in the treatment of SAD. In this study, a comparison has been made between the effects of broad-wavelength light without ultraviolet (UV) wavelengths compared to narrow-band blue light in the treatment of sub-syndromal seasonal affective disorder (Sub-SAD). Method In a 15-day design, 48 participants suffering from Sub-SAD completed 20-minute sessions of light treatment on five consecutive days. 22 participants were given bright white-light treatment (BLT, broad-wavelength light without UV 10 000 lux, irradiance 31.7 Watt/m2) and 26 participants received narrow-band blue light (BLUE, 100 lux, irradiance 1.0 Watt/m2). All participants completed daily and weekly questionnaires concerning mood, activation, sleep quality, sleepiness and energy. Also, mood and energy levels were assessed by means of the SIGH-SAD, the primary outcome measure. Results On day 15, SIGH-SAD ratings were significantly lower than on day 1 (BLT 54.8 %, effect size 1.7 and BLUE 50.7 %, effect size 1.9). No statistically significant differences were found on the main outcome measures. Conclusion Light treatment is an effective treatment for Sub-SAD. The use of narrow-band blue-light treatment is equally effective as bright white-light treatment

Do troublesome pupils impact teacher perception of the behaviour of their classmates?

The widely supported wish for more inclusive education places ever greater expectations on teachers’ abilities to teach all children, including those with special needs and challenging behaviours. The present study aimed at the question whether teachers judge pupil behaviour more negatively if there are more children with difficult behaviour in class. The teachers of 184 classes in 31 regular primary schools were asked to complete the Strength and Difficulties Questionnaire (SDQ-L) for 3649 pupils. Six linear mixed models were carried out with as independent variable the number of pupils that teachers perceived to have ‘abnormal behaviour’, and the class mean without these pupils as the dependent variable. For all SDQ-L subscales – emotional problems, behavioural problems, problems with hyperactivity, problems with peers, poor prosocial behaviour and total problems – the number of pupils perceived as problematic was associated with less favourable teacher perceptions of the rest of the class. The results of this study are a plea for a contextual perspective on pupil behaviour in class, both where teachers are asked to report on individual pupils, as well as where interventions are done on emotional and behavioural problems in class