Introduction: The purpose of this study is to determine if an earlier age at onset of positive symptoms in schizophrenia is associated with cannabis use disorders (CUD).Methods: 49 first-episode schizophrenia subjects with CUD were compared to 51 first-episode schizophrenia subjects with no substance use disorders for demographic and clinical variables. A multivariate logistic regression was performed to determine the joint relationship between variables significantly associated with CUD on univariate testing and ascertain if these variables independently predict CUD. Significance level was set at p<0.05.Results: 74% of CUD subjects had the onset of CUD before the onset of positive symptoms. Compared to non-substance abusing subjects, CUD subjects were predominantly male, younger at study entry, had an earlier age at onset of positive symptoms, less educational attainment, a lower self-socioeconomic status, better premorbid childhood social adjustment, a trend for poorer premorbid childhood academic adjustment, less motor abnormalities but more severe hallucinations and delusions. In the multivariate analysis, only male gender, worse socioeconomic status, better premorbid childhood social adjustment, and more severe positive symptoms at study entry were associated with a lifetime history of CUD.Discussion: Although cannabis use precedes the onset of illness in most patients, there was no significant association between onset of illness and CUD that was not accounted for by demographic and clinical variables. Previous studies implicating CUD in the onset of schizophrenia may need to more comprehensively assess the relationship between CUD and schizophrenia, and take into account additional variables that we found associated with CUD. (C) 2010 Elsevier B.V. All rights reserved.

This study assessed the relationship between duration of untreated psychosis (DUP) and cognitive measures in order to assess if longer DUP was associated with worse performance. One hundred two patients with first episode schizophrenia or schizoaffective disorder were assessed on cognitive measures of speed of processing, episodic memory, executive function, and visual spatial processing at baseline (when patients were drug naive and after 16 weeks of olanzapine or risperidone treatment), so that a change score could be derived. DUP was defined by the emergence of psychiatric symptoms and the emergence of psychotic symptoms. Data were analyzed correlationally, parametrically (after the group was divided into long and short DUP by median split), and by regression. We found that DUP for psychotic symptoms in this group of patients was long, with a median of 46 weeks. Neither correlational, parametric analyses in which DUP served as a class variable, nor multiple regression indicated that longer DUP was associated with worse cognition at baseline or smaller magnitude of improvement in cognition. Our results suggest that while early intervention may be critical for symptom amelioration by shortening DUP, early intervention for treatment of psychiatric symptoms may have little or no impact on cognitive function. Furthermore, assuming that cognition is a core symptom of schizophrenia, the notion that ongoing psychosis is somehow toxic for a variety of information processing domains appears questionable.

CONTEXTCognitive impairment in schizophrenia is frequent, involves multiple domains, and is enduring. Numerous recent clinical trials have suggested that second-generation antipsychotic medications significantly enhance cognition in schizophrenia. However, none of these studies included healthy controls undergoing repeated testing to assess the possibility that improvements might reflect simple practice effects.OBJECTIVETo report the results on cognition of a randomized comparison of 2 widely prescribed second-generation antipsychotic medications, olanzapine and risperidone, in patients with first-episode schizophrenia and a healthy control group.DESIGNRandomized clinical trial.SETTINGHospital-based research units. Patients A total of 104 participants with first-episode schizophrenia and 84 healthy controls.MAIN OUTCOME MEASURESCognitive assessment of all study participants occurred at baseline, 6 weeks later, and 16 weeks later. Neurocognitive tests included measures of working memory and attention, speed, motor function, episodic memory, and executive function.RESULTSNo differential drug effects were observed. Of 16 cognitive measures, 9 demonstrated improvement over time and only 2 demonstrated greater rates of change than those observed in the healthy control group undergoing repeated assessment. The composite effect size for cognitive change was 0.33 in the healthy control group (attributed to practice) and 0.36 in the patients with first-episode schizophrenia. Improvements in cognition in the first-episode schizophrenia group could not be accounted for by medication dose, demographic variables, or intellectual level.CONCLUSIONSThe cognitive improvements observed in the trial were consistent in magnitude with practice effects observed in healthy controls, suggesting that some of the improvements in cognition in the first-episode schizophrenia group may have been due to practice effects (ie, exposure, familiarity, and/or procedural learning). Our results also indicated that differential medication effects on cognition were small. We believe that these findings have important implications for drug discovery and the design of registration trials that attempt to demonstrate cognitive enhancement.

Objective: The authors compared 4-month treatment outcomes for olanzapine versus risperidone in patients with first-episode schizophrenia spectrum disorders.Method: One hundred twelve subjects (70% male; mean age = 23.3 years [SD = 5.1]) with first-episode schizophrenia (75%), schizophreniform disorder (17%), or schizoaffective disorder (8%) were randomly assigned to treatment with olanzapine (2.5 - 20 mg/ day) or risperidone (1 - 6 mg/ day).Results: Response rates did not significantly differ between olanzapine (43.7%, 95% CI = 28.8% - 58.6%) and risperidone (54.3%, 95% CI = 39.9% - 68.7%). Among those responding to treatment, more subjects in the olanzapine group (40.9%, 95% CI = 16.8% - 65.0%) than in the risperidone group (18.9%, 95% CI = 0% - 39.2%) had subsequent ratings not meeting response criteria. Negative symptom outcomes and measures of parkinsonism and akathisia did not differ between medications. Extrapyramidal symptom severity scores were 1.4 (95% CI = 1.2 - 1.6) with risperidone and 1.2 (95% CI = 1.0 - 1.4) with olanzapine. Significantly more weight gain occurred with olanzapine than with risperidone: the increase in weight at 4 months relative to baseline weight was 17.3% (95% CI = 14.2% - 20.5%) with olanzapine and 11.3% (95% CI = 8.4% - 14.3%) with risperidone. Body mass index at baseline and at 4 months was 24.3 (95% CI = 22.8 - 25.7) versus 28.2 (95% CI = 26.7 - 29.7) with olanzapine and 23.9 (95% CI = 22.5 - 25.3) versus 26.7 (95% CI = 25.2 - 28.2) with risperidone.Conclusions: Clinical outcomes with risperidone were equal to those with olanzapine, and response may be more stable. Olanzapine may have an advantage for motor side effects. Both medications caused substantial rapid weight gain,

Managerial decisions regarding timing of inventory replenishment are as important as determining the economic order size in inventory management. Yet most of the introductory texts on cost/managerial accounting and production/operations management do not adequately discuss reorder point determination, especially the condition on lead time demand that is necessary for valid application of the commonly reported formula for the reorder point. A clear understanding of the reorder point determination is important to students, teachers, and practicing managers alike. This note attempts to explain the underlying condition and modification needed in the reorder point formula.

Financial theory and empirical evidence suggest that a firm's systematic, or market related, risk is related to its financial conditions. This study empirically investigates the financial determinants of systematic risk for Real Estate Investment Trusts (REITs). The study is an examination of sample of 32 REITs for the period 1976–1978. The results indicate that systematic risk varies directly with financial leverage, business risk, and advisor fee. The explanatory power of the relationship between systematic risk and financial variables exceeds that of previous studies wherein firms were pooled across industry groups. The higher explanatory power observed even with limited data suggests that better estimates of coefficients of financial determinants of systematic risk may be obtained through analysis conducted on an industry by industry basis. Furthermore, such industry-specific analysis provides useful results to practicing financial managers in their financial policy considerations. With the knowledge of how the financial decisions affect the firm's systematic risk, a manager may be able to manipulate those variables so as to reduce the systematic risk for his or her firm and thus increase the market value of the firm's securities.