358 research outputs found
Individual differences in sexual responsiveness to estrogen and progesterone in ovariectomized rats
Individual differences among 83 ovariectomized rats in behavioral responsiveness to estrogen were measured by scoring the quality of sexual receptivity induced by injections of estradiol benzoate (EB) and progesterone (P). The P dose remained constant but the quantity of EB administered was systematically reduced over successive weeks until lordosis behavior could no longer be elicited. This EB dose was considered threshold. This sequence of weekly hormone injections and receptivity tests was repeated to assess the reliability of our procedures. Animals had thresholds of either 2.0, 1.0 or 0.5 [mu]g/kg EB on both tests; the correlation between threshold values on the two tests was high (r=0.66; p<0.001). Sixty-two females were used to determine the facilitating effects of various quantities of P following EB treatment. Subgroups were tested after the E alone and again after one of 6 P doses. Zero, 20, 50 and 100 [mu]g P failed to elevate receptivity scores significantly; both 250 and 500 [mu]g P had significant facilitating effects. The results demonstrated that individual differences in EB sensitivity can be measured reliably, and a further analysis also suggests similar individual differences in P responsiveness. Our threshold determination procedures provide a useful technique for measuring the effects of various experimental manipulations on the hormone sensitivity of brain mechanisms which regulate estrous behavior.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34132/1/0000416.pd
Hormonal induction of behavioral estrus modified by electrical stimulation of hypothalamus
Sexual receptivity was induced by sequential injections of estrogen and progesterone in ovariectomized female rats which had bilateral, monopolar electrodes permanently implanted into either the medial preoptic area (MPOA) or the medial basal hypothalamus (MBH). Intermittent electrical stimulation of the MPOA during the first 6 hours of estrogen priming significantly reduced the intensity of estrous behavior measured 2 days later. Comparable stimulation of the MBH produced a non-significant increase in receptivity. The use of electrical stimulation to study the ways in which hormones affect central sites of action is discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34075/1/0000354.pd
Asymmetry in the effects of unilateral 6-OHDA lesions on eating and drinking evoked by hypothalamic stimulation
The present experiment investigated the effects of unilateral 6-hydroxydopamine lesions of the caudate nucleus and nucleus accumbens on eating and drinking evoked by electrical stimulation of the lateral hypothalamus (ESLH). Lesions were made on either the `dominant' or `non-dominant' hemisphere as defined by an amphetamine-rotation test. We report here that lesions of the `dominant hemisphere' were significantly more effective in disrupting ESLH-evoked behavior as well as producing longer-lasting deficits in somatosensory responsiveness as measured by the `tactile extinction test'.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25680/1/0000233.pd
Long-lasting changes in morphine sensitivity following amygdaloid kindling in mice
Mice tested at either 3, 27 or 90 days following their last amygdala kindled convulsion exhibited a marked increase in response to morphine compared to controls. Kindled animals showed a higher incidence of clonic convulsions and an exaggerated Straub tail response, both of which could be blocked by naloxone pretreatment. The changes in response to morphine produced by kindling may provide a model for studying the long-lasting effects of convulsions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24190/1/0000449.pd
Patterns of primary care and mortality among patients with schizophrenia or diabetes: a cluster analysis approach to the retrospective study of healthcare utilization
Abstract Background Patients with schizophrenia have difficulty managing their medical healthcare needs, possibly resulting in delayed treatment and poor outcomes. We analyzed whether patients reduced primary care use over time, differentially by diagnosis with schizophrenia, diabetes, or both schizophrenia and diabetes. We also assessed whether such patterns of primary care use were a significant predictor of mortality over a 4-year period. Methods The Veterans Healthcare Administration (VA) is the largest integrated healthcare system in the United States. Administrative extracts of the VA's all-electronic medical records were studied. Patients over age 50 and diagnosed with schizophrenia in 2002 were age-matched 1:4 to diabetes patients. All patients were followed through 2005. Cluster analysis explored trajectories of primary care use. Proportional hazards regression modelled the impact of these primary care utilization trajectories on survival, controlling for demographic and clinical covariates. Results Patients comprised three diagnostic groups: diabetes only (n = 188,332), schizophrenia only (n = 40,109), and schizophrenia with diabetes (Scz-DM, n = 13,025). Cluster analysis revealed four distinct trajectories of primary care use: consistent over time, increasing over time, high and decreasing, low and decreasing. Patients with schizophrenia only were likely to have low-decreasing use (73% schizophrenia-only vs 54% Scz-DM vs 52% diabetes). Increasing use was least common among schizophrenia patients (4% vs 8% Scz-DM vs 7% diabetes) and was associated with improved survival. Low-decreasing primary care, compared to consistent use, was associated with shorter survival controlling for demographics and case-mix. The observational study was limited by reliance on administrative data. Conclusion Regular primary care and high levels of primary care were associated with better survival for patients with chronic illness, whether psychiatric or medical. For schizophrenia patients, with or without comorbid diabetes, primary care offers a survival benefit, suggesting that innovations in treatment retention targeting at-risk groups can offer significant promise of improving outcomes.http://deepblue.lib.umich.edu/bitstream/2027.42/78274/1/1472-6963-9-127.xmlhttp://deepblue.lib.umich.edu/bitstream/2027.42/78274/2/1472-6963-9-127.pdfPeer Reviewe
A survey of the clinical acceptability of screening for postnatal depression in depressed and non-depressed women
BACKGROUND: Information on clinical acceptability is needed when making cost-utility decisions about health screening implementation. Despite being in use for two decades, most data on the clinical acceptability of the Edinburgh Postnatal Depression Scale (EPDS) come from qualitative reports, or include relatively small samples of depressed women. This study aimed to measure acceptability in a survey of a relatively large, community sample with a high representation of clinically depressed women. METHODS: Using mail, telephone and face-to-face interview, 920 postnatal women were approached to take part in a survey on the acceptability of the EPDS, including 601 women who had screened positive for depression and 245 who had received DSM-IV diagnoses of depression. Acceptability was measured on a 5-point Likert scale of comfort ranging from "Not Comfortable", through "Comfortable" to "Very Comfortable". RESULTS: The response rate was just over half for postal surveys (52%) and was 100% for telephone and face-to-face surveys (432, 21 and 26 respondents for postal, telephone and face-to-face surveys respectively) making 479 respondents in total. Of these, 81.2% indicated that screening with the EPDS had been in the range of "Comfortable" to "Very Comfortable". The other 18.8 % rated screening below the "Comfortable" point, including a small fraction (4.3%) who rated answering questions on the EPDS as "Not Comfortable" at the extreme end of the scale. Comfort was inversely related to EPDS score, but the absolute size of this effect was small. Almost all respondents (97%) felt that screening was desirable. CONCLUSION: The EPDS had good acceptability in this study for depressed and non-depressed women. Women's views on the desirability of postnatal depression screening appear to be largely independent of personal level of comfort with screening. These results should be useful to policy-makers and are broadly supportive of the Edinburgh Postnatal Depression Scale as a suitable tool for universal perinatal depression screening
Has Behavioral Science Tumbled Through the Biological Looking Glass? Will Brief, Evidence-Based Training Return It From the Rabbit Hole?
Time constraints and professional demands leave practicing professionals unlikely to enroll in extended training such as a semester-long graduate course. Thus, the three-hour continuing education format has become a standard for those in practice. One may ask what sorts of training strategies optimize that format. To explore that, a three hour training program for seventy-six practicing mental health professionals, most of whom self-identified as psychologists, was devised. It made use of primarily antecedent techniques that have been shown to bring about changed perceptions on a number of topics. Content focused on two areas of importance to behavior analysts, the culture’s increasing acceptance of the biological causation model of disorders such as attentiondeficit hyperactivity disorder (ADHD), unipolar depression, anxiety disorders, and schizophrenia, and the field’s increasing reliance on medications, often to the exclusion of behavioral methods. Pre-post assessment showed that participants had changed their thinking regarding the two content areas. The authors caution that participants’ changed opinions may serve as setting events to changes in practice, but those changes are verbal. One must not assume changes in practice techniques will automatically occur
Adherence to antidepressant therapy for major depressive patients in a psychiatric hospital in Thailand
Poor adherence to antidepressant therapy is an important barrier to the effective management of major depressive disorder. This study aims to quantify the adherence rate to antidepressant treatment and to determine the pattern of prescriptions of depressed patients in a psychiatric institute in Thailand.This retrospective study used electronic pharmacy data of outpatients aged 15 or older, with a new diagnosis of major depression who received at least one prescription of antidepressants between August 2005 and September 2008. The medication possession ratio (MPR) was used to measure adherence over a 6 month period.1,058 were eligible for study inclusion. The overall adherence (MPR > 80%) in those attending this facility at least twice was 41% but if we assume that all patients who attended only once were non-adherent, adherence may be as low as 23%. Fluoxetine was the most commonly prescribed drug followed by TCAs. A large proportion of cases received more than one drug during one visit or was switched from one drug to another (39%).Adherence to antidepressant therapy for treatment of major depression in Thailand is rather low compared to results of adherence from elsewhere
Efficacy of olanzapine long-acting injection in patients with acutely exacerbated schizophrenia: an insight from effect size comparison with historical oral data
Time to discontinuation of atypical versus typical antipsychotics in the naturalistic treatment of schizophrenia
BACKGROUND: There is an ongoing debate over whether atypical antipsychotics are more effective than typical antipsychotics in the treatment of schizophrenia. This naturalistic study compares atypical and typical antipsychotics on time to all-cause medication discontinuation, a recognized index of medication effectiveness in the treatment of schizophrenia. METHODS: We used data from a large, 3-year, observational, non-randomized, multisite study of schizophrenia, conducted in the U.S. between 7/1997 and 9/2003. Patients who were initiated on oral atypical antipsychotics (clozapine, olanzapine, risperidone, quetiapine, or ziprasidone) or oral typical antipsychotics (low, medium, or high potency) were compared on time to all-cause medication discontinuation for 1 year following initiation. Treatment group comparisons were based on treatment episodes using 3 statistical approaches (Kaplan-Meier survival analysis, Cox Proportional Hazards regression model, and propensity score-adjusted bootstrap resampling methods). To further assess the robustness of the findings, sensitivity analyses were performed, including the use of (a) only 1 medication episode for each patient, the one with which the patient was treated first, and (b) all medication episodes, including those simultaneously initiated on more than 1 antipsychotic. RESULTS: Mean time to all-cause medication discontinuation was longer on atypical (N = 1132, 256.3 days) compared to typical antipsychotics (N = 534, 197.2 days; p < .01), and longer on atypicals compared to typicals of high potency (N = 320, 187.5 days; p < .01), medium potency (N = 140, 213.5 days; p < .01), and low potency (N = 74, 208.7 days; p < .01). Among the atypicals, only clozapine, olanzapine, and risperidone had significantly longer time to all-cause medication discontinuation compared to typicals, regardless of potency level, and compared to haloperidol with prophylactic anticholinergic treatment. When compared to perphenazine, a medium-potency typical antipsychotic, only clozapine and olanzapine had a consistently and significantly longer time to all-cause medication discontinuation. Results were confirmed by sensitivity analyses. CONCLUSION: In the usual care of schizophrenia patients, time to medication discontinuation for any cause appears significantly longer for atypical than typical antipsychotics regardless of the typical antipsychotic potency level. Findings were primarily driven by clozapine and olanzapine, and to a lesser extent by risperidone. Furthermore, only clozapine and olanzapine therapy showed consistently and significantly longer treatment duration compared to perphenazine, a medium-potency typical antipsychotic
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