Reflects a localized rather than a global increase in EBP1 expression corresponding to primordial follicle formation

The affinity of FGAs for dopamine D2 receptors leads to EPS. These agents bind more tightly than dopamine itself to the D2 receptors while SGAs bind less avidly than dopamine to D2 receptors and allow normal dopamine transmission. The reduced blockade of D2 receptors has also been linked to antagonism of 5-HT2A serotonin receptors. Serotonin regulates dopamine release and the presence of serotonin in nigrostriatal dopamine pathway inhibits the release of dopamine, subsequently reversing some of D2 blockade by SGAs. Antipsychotic agents within the SGA class vary in their affinity to D2 receptors and risperidone has the highest affinity. Nevertheless, risperidone has been widely prescribed, particularly to elderly patients, with the expectation of a lower incidence of EPS compared to FGA treatment. In this study such lower risk of movement disorders has been confirmed up to approximately a year of therapy; however, a trend toward a weaker association was observed and the 95%CI of the adjusted HR at 360 days suggested a loss of statistical significance. The interpretation of these results needs to consider the limitations of observational studies based on administrative data. However, a number of steps were taken to account for potential confounding. The key covariates that are associated with outcome or exposure were identified and adjustments were made in the analysis. Age, sex, residence in a PCH and comorbidities were used to control for a possible selection bias. The index year was included into the adjusted models to account for possible changes in medical practice over the time frame of this study. The time frame of the study cohort did not include the time period of 1998 to 2000 when much of the shift between FGA and SGA use happened. No attempt was made to evaluate the effect of dose on incidence of EPS in this population, as small dose adjustments that commonly and continuously occur in clinical practise are not accurately captured by an observational study design that utilizes exclusively administrative data. Nevertheless, it is well known that EPS are dose-related and high doses of risperidone are expected to cause movement effects similar to those caused by FGAs. Furthermore, this study did not address the benefits of using antipsychotic pharmacotherapy, especially because quality of life cannot be assessed in observational studies that are based on administrative data. Yet the findings of this research provide a real-world observation that the use of risperidone is associated with lower risk for dyslipidemia was adjusted for major systemic parameters including socioeconomic factors potentially debilitating EPS adverse events in elderly subjects compared to the traditional antipsychotic medications. The advantage of this study is the fact that the entire elderly population of a Canadian province was included without restrictions due to insurance coverage or limited access. The results can be generalizable to other populations as they are not affected by sampling errors or recall bias.