No abstract

The relationship between companion animal ownership and wellbeing has received an increasing amount of scientific attention over the last few decades. Although the general assumption is that individuals benefit from the presence of companion animals (termed the "pet-effect"), recent evidence suggests that the nature of this association is diverse and complex and that many of the studies performed so far are subject to methodological constraints. This study therefore aimed to investigate the pet-effect in the natural setting of pet-owners' daily life. Using the Experience Sampling Method (a signal contingent ecological assessment technique), 55 dog or cat owners reported for five consecutive days, at ten random time-points each day, in the moment whether a pet was present and to what extent they interacted with it. In addition, at each measurement moment they reported on their current positive and negative affect, using 11 mood-related adjectives derived from the Positive And Negative Affect Schedule (PANAS). Multilevel regression analyses showed that negative affect was relatively lower at moments when the companion animal was present (vs. absent) (B = -0.09, p = 0.02, 95%CI = -0.16; -0.02). In addition, the level of interaction with a companion animal was positively associated with positive affect (B = 0.04, p < 0.001, 95%CI = 0.01; 0.07). These results are in line with the pet-effect hypothesis in suggesting that the presence of and interaction with companion animals is associated with aspects of emotional wellbeing. More specifically, the presence of a companion animal may buffer against negative feelings, while interacting with a companion animal may generate positive feelings. This differential effect on positive versus negative affect also shows that the pet-effect is not an unequivocal effect. Different aspects of the human-animal relationship may influence different aspects of wellbeing.

BackgroundS100B is a potential marker of neurological and psychiatric illness. In schizophrenia, increased S100B levels, as well as associations with acute positive and persisting negative symptoms, have been reported. It remains unclear whether S100B elevation, which possibly reflects glial dysfunction, is the consequence of disease or compensatory processes, or whether it is an indicator of familial risk.MethodsSerum samples were acquired from two large independent family samples (n = 348 and n = 254) in the Netherlands comprising patients with psychotic disorder (n = 140 and n = 82), non-psychotic siblings of patients with psychotic disorder (n = 125 and n = 94) and controls (n = 83 and n = 78). S100B was analyzed with a Liaison automated chemiluminescence system. Associations between familial risk of psychotic disorder and S100B were examined.ResultsResults showed that S100B levels in patients (P) and siblings (S) were not significantly different from controls (C) (dataset 1: P vs. C: B = 0.004, 95% CI −0.005 to 0.013, p = 0.351; S vs. C: B = 0.000, 95% CI −0.009 to 0.008, p = 0.926; and dataset 2: P vs. C: B = 0.008, 95% CI −0.011 to 0.028, p = 0.410; S vs. C: B = 0.002, 95% CI −0.016 to 0.021, p = 0.797). In patients, negative symptoms were positively associated with S100B (B = 0.001, 95% CI 0.000 to 0.002, p = 0.005) in one of the datasets, however with failure of replication in the other. There was no significant association between S100B and positive symptoms or present use or type of antipsychotic medication.ConclusionsS100B is neither an intermediate phenotype, nor a trait marker for psychotic illness.

BackgroundResearch suggests that altered interregional connectivity in specific networks, such as the default mode network (DMN), is associated with cognitive and psychotic symptoms in schizophrenia. In addition, frontal and limbic connectivity alterations have been associated with trauma, drug use and urban upbringing, though these environmental exposures have never been examined in relation to DMN functional connectivity in psychotic disorder.MethodsResting-state functional MRI scans were obtained from 73 patients with psychotic disorder, 83 non-psychotic siblings of patients with psychotic disorder and 72 healthy controls. Posterior cingulate cortex (PCC) seed-based correlation analysis was used to estimate functional connectivity within the DMN. DMN functional connectivity was examined in relation to group (familial risk), group × environmental exposure (to cannabis, developmental trauma and urbanicity) and symptomatology.ResultsThere was a significant association between group and PCC connectivity with the inferior parietal lobule (IPL), the precuneus (PCu) and the medial prefrontal cortex (MPFC). Compared to controls, patients and siblings had increased PCC connectivity with the IPL, PCu and MPFC. In the IPL and PCu, the functional connectivity of siblings was intermediate to that of controls and patients. No significant associations were found between DMN connectivity and (subclinical) psychotic/cognitive symptoms. In addition, there were no significant interactions between group and environmental exposures in the model of PCC functional connectivity.DiscussionIncreased functional connectivity in individuals with (increased risk for) psychotic disorder may reflect trait-related network alterations. The within-network “connectivity at rest” intermediate phenotype was not associated with (subclinical) psychotic or cognitive symptoms. The association between familial risk and DMN connectivity was not conditional on environmental exposure.

Background Previous studies have suggested that culture impacts the experience of psychosis. The current study set out to extend these findings by examining cultural variation in subclinical positive psychotic experiences in students from The Netherlands, Nigeria, and Norway. Positive psychotic experiences were hypothesized to (i) be more frequently endorsed by, and (ii) cause less distress in Nigerian vs. Dutch and Norwegian students. Methods Psychology students, aged 18 to 30 years, from universities in the Netherlands ( n = 245), Nigeria ( n = 478), and Norway ( n = 162) were assessed cross-sectionally with regard to the frequency of subclinical positive psychotic experiences and related distress, using the Community Assessment of Psychic Experiences (CAPE-42). Multi-group confirmatory factor analysis and multivariate analysis of covariance were performed to assess measurement invariance of the positive symptom dimension (CAPE- Pos ) and compare mean frequency and associated distress of positive psychotic experiences across study samples. Results Only CAPE- Pos items pertaining to the dimensions ‘strange experiences’ and ‘paranoia’ met assumptions for (partial) measurement invariance. Frequencies of these experiences were higher in the Nigerian sample, compared to both the Dutch and Norwegian samples, which were similar. In addition, levels of experience-related distress were similar or higher in the Nigerian sample compared to respectively the Dutch and Norwegian samples. Conclusion Although positive psychotic experiences may be more commonly endorsed in non-Western societies, our findings do not support the notion that they represent a more benign, and hence less distressing aspect of human experience. Rather, the experience of psychotic phenomena may be just as, if not more, distressing in African than in European culture. However, observed differences in CAPE- Pos frequency and distress between samples from different cultural settings may partly reflect differences in the measure rather than in the latent trait. Future studies may therefore consider further cross-cultural adaptation of CAPE-42, in addition to explicitly examining cultural acceptance of psychotic phenomena, and environmental and other known risk factors for psychosis, when comparing and interpreting subclinical psychotic phenomena across cultural groups.

Background: Although widespread reduced white matter (WM) integrity is a consistent finding in cross-

A balanced time perspective can help retaining or improving happiness. Research shows shifts in time perspective while ageing. In order to reach a better understanding of the value of time perspective in different age groups, results are reported of a survey (n = 525), which examines the moderating role of age in the association between time perspective and happiness. Time perspective was measured by the Zimbardo Time Perspective Inventory (ZTPI) (Zimbardo and Boyd in J Personal Soc Psychol 77: [1271][1272][1273][1274][1275][1276][1277][1278][1279][1280][1281][1282][1283][1284][1285][1286][1287][1288] 1999) and to measure happiness, the Subjective Happiness Scale of Lyubomirsky and Lepper (Soc Indic Res 46:137-155, 1999) was used. Regression analysis shows that time perspective is indeed associated with happiness and that, although the assumed shifts in time perspective over time were not found, age does act as a moderator of this association. With ageing, the negative association between a past-negative time perspective and happiness weakens. These results add to our understanding of the theoretical concept of time perspective and shed new light on the value of a balanced time perspective for someone's wellbeing. Theoretical and practical implications of these findings are discussed.

BackgroundDysconnectivity in schizophrenia can be understood in terms of dysfunctional integration of a distributed network of brain regions. Here we propose a new methodology to analyze complex networks based on semi-metric behavior, whereby higher levels of semi-metricity may represent a higher level of redundancy and dispersed communication. It was hypothesized that individuals with (increased risk for) psychotic disorder would have more semi-metric paths compared to controls and that this would be associated with symptoms.MethodsResting-state functional MRI scans were obtained from 73 patients with psychotic disorder, 83 unaffected siblings and 72 controls. Semi-metric percentages (SMP) at the whole brain, hemispheric and lobar level were the dependent variables in a multilevel random regression analysis to investigate group differences. SMP was further examined in relation to symptomatology (i.e., psychotic/cognitive symptoms).ResultsAt the whole brain and hemispheric level, patients had a significantly higher SMP compared to siblings and controls, with no difference between the latter. In the combined sibling and control group, individuals with high schizotypy had intermediate SMP values in the left hemisphere with respect to patients and individuals with low schizotypy. Exploratory analyses in patients revealed higher SMP in 12 out of 42 lobar divisions compared to controls, of which some were associated with worse PANSS symptomatology (i.e., positive symptoms, excitement and emotional distress) and worse cognitive performance on attention and emotion processing tasks. In the combined group of patients and controls, working memory, attention and social cognition were associated with higher SMP.DiscussionThe results are suggestive of more dispersed network communication in patients with psychotic disorder, with some evidence for trait-based network alterations in high-schizotypy individuals. Dispersed communication may contribute to the clinical phenotype in psychotic disorder. In addition, higher SMP may contribute to neuro- and social cognition, independent of psychosis risk.