The Effect of Intranasal Oxytocin on the Association Between Couple Interaction and Sleep: A Placebo-Controlled Study.

OBJECTIVE: Although most people in romantic relationships cosleep, biosocial modulators of sleep quality have only recently come into focus. Oxytocin (OT) might be one such modulator, as it had been shown to increase social attachment and safety. We investigated the association between everyday life couple interaction and sleep quality, as well as the effects of OT on this association. METHODS: Eighty heterosexual couples ( N = 160 individuals, mean [standard deviation] age = 28 [5] years) were randomized to self-administer a) 32 international units of intranasal OT or b) placebo during 5 consecutive days. Each morning, they reported on sleep quality, and on subjective feelings of closeness and valence of couple interaction at a maximum of four times a day. Data were analyzed using hierarchical linear models. RESULTS: Subjective closeness ( B = 0.43, t (73) = 3.80, p < .001) and valence (negative - positive) of couple interaction ( B = 0.50, t (73) = 3.91, p < .001) were positively associated with sleep quality. Persons with OT reported higher levels of sleep quality than those without ( B = 0.47, t (74) = 2.32, p = .023). The association between closeness and sleep quality was stronger with OT than without (OT by closeness: B = 0.31, t (72) = 2.29, p = .025; OT by valence of interaction: B = 0.27, t (72) = 1.77, p = .081). Whereas the effect of couple interaction on sleep quality was strong in men, the OT effects were especially pronounced in women. CONCLUSIONS: Our results suggest that enhancing closeness and positive couple interaction in cosleeping partners might be a way to improve sleep quality. The moderating effects of OT and sex on the association between couple interaction and sleep quality can have important implications for sleep therapy.Trial Registration: The study was preregistered at ClinicalTrials.gov ("Oxytocin, Couple Interaction, and Wound Healing" study, identifier NCT01594775). The present analyses were not preregistered.

Statistical Comparison of Trait-Dependent Biogeographical Models Indicates That Podocarpaceae Dispersal Is Influenced by Both Seed Cone Traits and Geographical Distance.

The ability of lineages to disperse long distances over evolutionary timescales may be influenced by the gain or loss of traits adapted to enhance local, ecological dispersal. For example, some species in the southern conifer family Podocarpaceae have fleshy cones that encourage bird dispersal, but it is unknown how this trait has influenced the clade's historical biogeography, or its importance compared with other predictors of dispersal such as the geographic distance between regions. We answer these questions quantitatively by using a dated phylogeny of 197 species of southern conifers (Podocarpaceae and their sister family Araucariaceae) to statistically compare standard, trait-independent biogeography models with new BioGeoBEARS models where an evolving trait can influence dispersal probability, and trait history, biogeographical history, and model parameters are jointly inferred. We validate the method with simulation-inference experiments. Comparing all models, those that include trait-dependent dispersal accrue 87.5% of the corrected Akaike Information Criterion (AICc) model weight. Averaged across all models, lineages with nonfleshy cones had a dispersal probability multiplier of 0.49 compared with lineages with fleshy cones. Distance is included as a predictor of dispersal in all credible models (100% model weight). However, models with changing geography earned only 22.0% of the model weight, and models submerging New Caledonia/New Zealand earned only 0.01%. The importance of traits and distance suggests that long-distance dispersal over macroevolutionary timespans should not be thought of as a highly unpredictable chance event. Instead, long-distance dispersal can be modeled, allowing statistical model comparison to quantify support for different hypotheses.

Poor night's sleep predicts following day's salivary alpha-amylase under high but not low stress.

Although sleep is linked to physiological stress systems like the autonomic nervous system (ANS), research is still limited regarding night-and-day interactions between nocturnal sleep characteristics, stress, and diurnal parameters of salivary alpha-amylase (sAA) as a surrogate marker of ANS activity. Fifty healthy university students rated their chronic stress burden and completed two five-day periods of ecological momentary assessment - under everyday conditions of both low stress (beginning of semester) and high stress (final examination preparation). Participants collected saliva six times daily and reported on the previous night's sleep (quality, latency, duration, disturbances) immediately after awakening. Additionally, a sub-sample wore actigraphs recording 'time in bed'. In contrast to previous assumptions, poor sleep predicted lower sAA awakening values, more decreased awakening responses, and steeper diurnal slopes the following day only under high stress, but not under low stress. Diurnal sAA parameters did not predict the following night's sleep characteristics. The sAA profile does not seem to be sensitive to everyday occurring sleep variations, but rather seems to be an indicator of more prolonged stress induced ANS dysregulation.

Screening for DSM-5 Somatic Symptom Disorder: Diagnostic Accuracy of Self-Report Measures Within a Population Sample.

OBJECTIVE: The new DSM-5 somatic symptom disorder was introduced to improve the diagnosis of persons experiencing what used to be called somatoform disorders. So far, it is unclear whether existing self-report measures are useful to detect the new somatic symptom disorder. This study investigates the diagnostic accuracy of three self-report questionnaires that measure somatic complaints (15 item Patient Health Questionnaire [PHQ-15]) and psychological features (7-item Whiteley Index [WI-7]; Scale for Assessing Illness Behavior [SAIB]), in detecting somatic symptom disorder. METHODS: A nationally representative general population survey was performed resulting in 250 participants (minimum age = 14 years. 12.8% participation rate). Assessment took place at baseline and 12-month follow-up. Individual and combined diagnostic accuracy of the PHQ-15, WI-7, and SAIB in detecting somatic symptom disorder was evaluated using the area under the curve (AUC) of a receiver operating characteristic. RESULTS: Diagnostic accuracy was adequate to good for each individual questionnaire (PHQ-15: AUC = 0.79, p < .001, 95% confidence interval [CI] = 0.73-0.85; WI-7: AUC = 0.76, p < .001, 95% CI = 0.69-0.83; SAIB: AUC = 0.77, p < .001, 95% CI = 0.71-0.83). Combining the PHQ-15 and the WI-7 slightly improved diagnostic accuracy (AUC = 0.82, p < .001, 95% CI = 0.77-0.88), as did the combination of all three questionnaires (AUC = 0.85, p < .001, 95% CI = 0.79-0.90). CONCLUSIONS: The PHQ-15, WI-7, and SAIB are useful screening instruments to detect persons at risk for somatic symptom disorder, and a combination of these three instruments slightly improves diagnostic accuracy. Their use in routine care will lead to improved detection rates.

Historical biogeography of the ancient lycophyte genus Selaginella: early adaptation to xeric habitats on Pangea.

The ancient and cosmopolitan lycophyte genus Selaginella has living representatives around the world, but their historical biogeography has not been assessed with modern methods. We estimated a time-calibrated phylogeny using DNA marker regions rbcL and ITS1-5.8S-ITS2 from 200 species. Node density analyses revealed that Selaginellaceae has significantly older median and mean node ages than other putative "ancient" families. We used statistical model comparison to assess different biogeographical models on our dated tree, and to estimate ancestral ranges. These revealed that Selaginella originated on Euramerica around 383 Ma in the Devonian period, while its peak diversification began with the formation of Pangea. The divergence of the two main species-rich Selaginella lineages occurred approximately 318 Ma on the supercontinent. The major divergences within these main lineages of Selaginella took place in the Late Permian and Early Triassic, along with lineages highly adapted for xeric habitats on Pangea.

Classifying Fibromyalgia Syndrome as a Mental Disorder?-An Ambulatory Assessment Study.

PURPOSE: Fibromyalgia syndrome (FMS) is associated with psychological distress. The recent revision of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) raises the question of whether FMS is classifiable as "somatic symptom disorder" (SSD) and consequently as a mental disorder. To address this, the present ambulatory assessment study focuses on the everyday life occurrence of SSD symptoms in FMS and their predictive value concerning severity indicators of widespread pain. METHOD: Ambulatory data were assessed six times daily on 14 consecutive days via iPod. Twenty-eight women suffering from FMS indicated symptoms associated with SSD (somatic illness beliefs, health anxiety, time/energy devoted to pain, or health concerns) and momentary pain levels. Questionnaires regarding potential covariates (such as somatization, depression, health status) were completed at two additional sessions in the research laboratory. RESULTS: On average, SSD symptoms occurred three to four times daily and were mild to moderate in severity. Furthermore, these symptoms were both concurrently and prospectively associated with momentary pain intensity and subjective impairment by pain. Twenty percent of the variance in pain intensity and 28 % of the variance in subjective impairment were explained by momentary variables (SSD symptoms and intake of pain medication). Eighty-two percent of persons with FMS fulfilled the psychological SSD criterion when considering everyday occurring symptoms with at least mild severity. CONCLUSION: FMS might be diagnosed as a mental disorder according to DSM-5 in many cases. SSD symptoms proved to have predictive value for FMS severity and may thus have clinical relevance for diagnostic, prognostic, and intervention purposes.

Validating psychological classification criteria in the context of somatoform disorders: A one- and four-year follow-up.

When revising the former somatoform diagnoses to somatic symptom disorders, DSM-5 introduced psychological classification criteria in addition to somatic symptoms. The authors investigated the relevance of these and further cognitive, affective, and behavioral features as well as their predictive value concerning (a) somatic symptoms that are not better explained by a general medical condition (MUS) and somatoform disorders (SD), (b) impairment, and (c) health care utilization. A general population sample of 321 participants (M = 47.0 years, 63% women) was interviewed at baseline and reinterviewed 1 year (N = 244) and 4 years (N = 219) later. The authors assessed a list of 49 somatic complaints including medical causes, the symptom-related subjective impairment, doctor visits during the previous 12 months, depressive/anxiety disorders (SCID), and 9 psychological features with potential use for classification. Most psychological features were more frequent in subjects with SD compared to nonsufferers. Reassurance seeking, body checking, a self-concept of bodily weakness, catastrophizing of physical sensations, avoidance of physical activities, and negative affectivity incrementally predicted medium- and long-term standard deviation: The odds ranged from 2.4 to 9.8 (95% confidence intevals: [1.1, 5.0], [1.7-57.9]), with up to 90% correct predictions for the overall model. Lower somatic symptom attribution and higher health anxiety were incremental predictors of the number of MUS after 4 years. Long-term impairment and health care use were not incrementally predicted by psychological features. To conclude, psychological criteria showed relevance and predictive value for the classification of somatoform symptoms. Therefore, the inclusion seems warranted, although the DSM-5 selection of psychological features needs further investigation.

The distinction between "medically unexplained" and "medically explained" in the context of somatoform disorders.

PURPOSE: Medically unexplained symptoms (MUS) currently constitute the main diagnostic criterion of somatoform disorders. It has been proposed that the required dichotomization of somatic complaints into MUS and medically explained symptoms (MES) should be abandoned in DSM-V. The present study investigated complaints in the general population in order to evaluate the relevance of a distinction between MUS and MES. METHODS: Three hundred twenty-one participants from a population-based sample were interviewed by telephone to assess symptoms present during the previous 12 months. Complaints were examined in terms of health care use, diagnoses made by the physician and degree of impairment. At the 1-year follow-up, 244 subjects were re-interviewed in order to explore the stability of symptoms. RESULTS: The complaints frequently prompted participants to seek medical health care (several pain and pseudoneurological symptoms led to a doctors' visit in >80 % of cases), although etiological findings rarely suggested a medical pathology (occasionally <30 %). MUS and MES proved, to an equal degree, to impair individuals and prompt a change in lifestyle. Pain caused the worst impairment compared with other symptoms. The most prevalent MUS and MES were characterized by a transient course (approximately 60 % remitted, 55 % newly emerged to follow-up), although various unexplained pain complaints tended to be persistent (e.g., back pain 67 %). Remarkably, the appraised etiology as explained or unexplained changed from baseline to follow-up in many persisting symptoms (20 % MUS → MES, 50 % MES → MUS). CONCLUSIONS: In principal, MUS and MES resulted in comparable impairment and stability. Due to conceptual and methodological difficulties, classification criteria for somatoform disorders should not be restricted to somatic aspects of the symptomatology.