Pet companionship and depression: Results from a United States Internet sample

Abstract

Using Internet survey data from 2,291 respondents from the United States, we examined socio-demographic predictors of living with a cat or dog. Logistic regressions showed that, for men, being married, living with children, being Midwestern and non-urban increased odds of living with a pet. For women, being White, having a high income, living with children, and living in a rural setting increased odds for pet ownership. Multivariate analyses examining influences of gender, marital status, and pet ownership on depression (CES-D) scores, adjusting for potential confounders, revealed that unmarried women who live with a pet have the fewest depressive symptoms, and unmarried men who live with a pet have the most. These findings suggest that single women benefit from pet companionship, whereas single men may be burdened by it.     

Inbreeding depression effects on extinction time in a predator—prey system

Summary Traditional methods of assessing population viability ignore both genetic—demographic interactions as well as community level dynamics. We address these deficiencies by presenting a model that investigates the effects of predation on a prey population experiencing inbreeding depression. Beginning with a simple Lotka—Volterra predator—prey system, we rewrite prey per capita mortality as a function of inbreeding. Inbreeding varies as a function of population size. Using computer simulation, we find that prey extinction times are inversely related to the level of inbreeding depression with and without predation. For all but very low levels of inbreeding depression, predation appreciably reduces persistence time. At moderate levels of inbreeding, predators go extinct before prey. When migration is introduced at low and moderate rates, persistence times only improve for those populations with low inbreeding depression measures. At a higher migration rate, persistence times are lengthened for low and moderately depressed prey populations. Increasing birth rates produce a visible, though noisy, trend towards increased times to extinction for low to moderate levels of inbreeding.     

Among-individual variation in pollen limitation and inbreeding depression in a mixed-mating shrub

Background and Aims

Variation in inbreeding depression (δ) among individual plants is considered to play a central role in mating system evolution and population genetics. Moreover, such variation could be linked to individual susceptibility to pollen limitation (PL) because those individuals strongly affected by δ for seed production will require more outcross pollen for setting a given number of fruits or seeds. However, no study has tested explicitly for associations between PL and δ at the individual plant level. This study assesses the extent of among-individual variation in PL and δ, the consistency of δ across life stages, and the relationships between individual PL and δ in the mixed-mating shrub Myrtus communis.

Methods

Controlled hand-pollinations were performed in a natural M. communis population. Marked flowers were monitored until fruit production and a greenhouse experiment was conducted with the seeds produced.

Key Results

Compared with selfing, outcross-pollination enhanced seed number per fruit, germination rate and seedling growth, but did not enhance fruit-set. Only seed number per fruit was pollen limited and, thus, cumulative pollen limitation depended more on pollen quality (outcross pollen) than on quantity. The effects of δ varied considerably across life stages and individual plants. Cumulative δ was high across individuals (mean δ = 0·65), although there were no positive correlations between δ values at different life stages. Interestingly, maternal plants showing stronger δ for seed production were more pollen limited, but they were also less affected by δ for seedling growth because of a seed size/number trade-off.

Conclusions

Results show a general inconsistency in δ across life stages and individuals, suggesting that different deleterious loci are acting at different stages. The association between δ and PL at the individual level corroborates the idea that pollen limitation may be ‘genotype-dependent’ regardless of other factors.     

刺五加对抑郁症大鼠行为学的影响

目的:研究刺五加对抑郁症动物行为学的影响。方法:采用大鼠强迫游泳试验,确定实验中刺五加治疗组剂量。采用慢性温和性不可预知应激(CUMS)+孤养的方法复制大鼠抑郁模型,将48只SD雄性大鼠分为6组(n=8):正常对照组(NC)、空白对照组(BC)、实验对照组(EC)、刺五加浸膏治疗组(AS)、盐酸氯丙咪嗪治疗组(CH)及刺五加浸膏+盐酸氯丙咪嗪联合治疗组(A+C),观察大鼠糖水偏爱度、体重增长和行为学改变。结果:在强迫游泳实验中,一定剂量的刺五加浸膏能明显缩短大鼠水面停留时间,其中600mg/kg剂量作用最为显著。在CUMS+孤养抑郁模型动物实验中,与NC组相比,BC组和EC组中央格停留时间显著增加(P0.05),其它各项指标显著减少(P0.05),BC组和EC组间各项指标没有显著差异(P0.05);经过28天的治疗后,AS组的中央格停留时间和穿越格数,CH组的穿越格数和清洁运动次数有改善但与NC组相比仍有显著差异(P0.05),AS组、CH组的其余各项指标及A+C组的各项指标都恢复至NC组水平(P0.05)。结论:刺五加在改善抑郁模型大鼠快感缺乏和其他行为学变化方面的作用与盐酸氯丙咪嗪相似,在提高动物对周围环境的要求及对自身的关注度方面略优于盐酸氯丙咪嗪。联合用药能有效改善各种症状且效果优于单独用药。     

Perinatal depression: implications for child mental health

Perinatal depression is common and primary care holds a crucial role for detecting, treating or, if necessary, providing referrals to mental health care for affected women. Family doctors should be aware of risk factors for peripartum depression, including previous history of depression, life events and interpersonal conflict. Perinatal depression has been associated with many poor outcomes, including maternal, child and family unit challenges. Infants and young children of perinatally depressed mothers are more likely to have a difficult temperament, as well as cognitive and emotional delays. The primary care setting is uniquely poised to be the screening and treatment site for perinatal depression; however, several obstacles, both at patient and systems level, have been identified that interfere with women's treatment engagement. Current published treatment guidelines favour psychotherapy above medicines as first line treatment for mild to moderate perinatal depression, while pharmacotherapy is first choice for severe depression, often in combination with psychosocial or integrative approaches. Among mothers who decide to stop taking their antidepressants despite ongoing depression during the perinatal period, the majority suffer from relapsing symptoms. If depression continues post-partum, there is an increased risk of poor mother-infant attachment, delayed cognitive and linguistic skills in the infant, impaired emotional development and risk for behavioural problems in later life. Complex, comprehensive and multilevel algorithms are warranted to treat perinatal depression. Primary care doctors are best suited to initiate, carry out and evaluate the effectiveness of such interventions designed to prevent adverse outcomes of maternal perinatal depression on mother and child wellbeing.     

Correlation between mental health co-morbidity screening scores and clinical response in collaborative care treatment for depression

The hypothesis for this paper is that adult patients who have higher screening scores for mental health co-morbidities and depression have a greater likelihood of not responding to treatment with collaborative care management (CCM) for their depression within six months.For the 334 patients in this study, the primary endpoints were if the patient was in remission at six months (PHQ-9 score <5) or if they were non-responsive (NR) (PHQ-9 >50% of baseline score). Initial evaluation included screening for alcoholism (AUDIT), anxiety (GAD-7) and bipolar disorders (MDQ).The differences in marital status, percentage of minority patients, gender, initial PHQ-9 and AUDIT scores were not statistically significant. Mood Disorders Questionnaire (MDQ) screening was more likely to be negative for the group in remission (96.2% vs 90.0%, P=0.049) and positive for the NR group (8.0% vs 2.1%, P=0.026). GAD-7 screening was significantly lower in the remission group (9.85) than in the NR group (11.53, P=0.009).Results of multiple logistic regression analysis demonstrated that age, gender, race, marital status, PHQ-9 score and AUDIT score were not related to the odds of being NR. A one-point higher GAD-7 score was associated with approximately 6% higher adjusted odds of being NR. Patients with a positive MDQ were associated with elevated odds of non-response (adjusted OR=3.4714, P=0.044) when controlling for all other variables.A higher initial screening score for anxiety or bipolar disorder is associated with a statistically significant increase in the relative risk of patients in CCM not responding to current treatments for depression within six months.     

RECONSTRUCTING ORIGINS OF LOSS OF SELF‐INCOMPATIBILITY AND SELFING IN NORTH AMERICAN ARABIDOPSIS LYRATA: A POPULATION GENETIC CONTEXT

Theoretical and empirical comparisons of molecular diversity in selfing and outcrossing plants have primarily focused on long‐term consequences of differences in mating system (between species). However, improving our understanding of the causes of mating system evolution requires ecological and genetic studies of the early stages of mating system transition. Here, we examine nuclear and chloroplast DNA sequences and microsatellite variation in a large sample of populations of Arabidopsis lyrata from the Great Lakes region of Eastern North American that show intra‐ and interpopulation variation in the degree of self‐incompatibility and realized outcrossing rates. Populations show strong geographic clustering irrespective of mating system, suggesting that selfing either evolved multiple times or has spread to multiple genetic backgrounds. Diversity is reduced in selfing populations, but not to the extent of the severe loss of variation expected if selfing evolved due to selection for reproductive assurance in connection with strong founder events. The spread of self‐compatibility in this region may have been favored as colonization bottlenecks following glaciation or migration from Europe reduced standing levels of inbreeding depression. However, our results do not suggest a single transition to selfing in this system, as has been suggested for some other species in the Brassicaceae.     

Glycine receptor activation regulates short-term plasticity in CA1 area of hippocampal slices of rats

Functional glycine receptors (GlyRs) are enriched in the hippocampus, but their roles in synaptic transmission are unclear. In this study, we examined the effect of GlyR activation on paired-pulse stimulation of the whole-cell postsynaptic currents (PSCs) in the Schaffer-CA1 synapses in rat hippocampal slices. Bath application of glycine reduced the amplitude of PSCs, accompanied by an increase in holding current and resting conductance. Moreover, glycine application increased the paired-pulse ratio (PPR) of PSCs significantly, an effect largely abolished by the GlyR specific antagonist strychnine. Interestingly, glycine application had no significant effect on either the amplitude or the PPR of excitatory postsynaptic currents (EPSCs). Our findings suggest that GlyR activation regulates hippocampal short-term plasticity by altering GABAergic neurotransmission.     

Ketamine-induced cardiac depression is associated with increase in [Mg2+]i and activation of p38 MAP kinase and ERK 1/2 in guinea pig

This study investigated the signaling pathways responsible for ketamine-induced cardiac depression in guinea pigs. The left ventricular development pressure (LVDP), velocity of the change in pressure (dP/dt), and heart rate (HR) accompanied with the total magnesium efflux ([Mg]e) were measured simultaneously in perfused hearts. The level of activation of the extracellular signal-regulated kinases 1/2 (ERK 1/2) and p38 mitogen-activated protein (MAP) kinase. The intracellular ionized magnesium concentration ([Mg2+]i) was measured using Mag-fura 2 AM in a single cardiomyocyte. Ketamine produced reversible decreases in the LVDP, dP/dt, and HR accompanied by increases in the [Mg]e. Ketamine also produced significant activation of p38 MAP kinase and ERK 1/2, and produced a dose-dependent increase in the [Mg2+]i, which was inhibited SB203580 and PD98059. These results suggest that ketamine-induced cardiac depression can be partly responsible for the increase in [Mg2+]i and [Mg]e, accompanied by the activation of p38 MAP kinase and ERK 1/2 in guinea pigs.