Published papers

The 2nd Schizophrenia International Research Society Conference, was held in Florence, Italy, April 10-15, 2010. Student travel awardees served as rapporteurs of each oral session and focused their summaries on the most significant findings that emerged from each session and the discussions that followed. The following report is a composite of these reviews. It is hoped that it will provide an overview for those who were present, but could not participate in all sessions, and those who did not have the opportunity to attend, but who would be interested in an update on current investigations ongoing in the field of schizophrenia research.

Objective: To compare antipsychotic prescribing patterns in younger (aged 59 years or younger) and older (aged 60 years or older) patients with psychotic or mood disorders. Method: Pharmacy records of all patients discharged from the Centre for Addiction and Mental Health over a 21-month period were reviewed. A total of 1357 patients who were prescribed an antipsychotic at the time of their discharge were included in the analysis (956 with a primary psychotic disorder and 401 with a primary mood disorder). World Health Organization-defined daily doses were used as the standardized dosing unit. Results: Both in patients with a primary psychotic disorder and in patients with a primary mood disorder, the prescribing patterns were similar in older and younger patients, with no statistical difference in the proportions receiving first-generation antipsychotics, second-generation antipsychotics (SGAs), multiple antipsychotics, or long-acting (depot) antipsychotics. Overall, the mean daily antipsychotic doses were lower only in the older group of patients with a primary mood disorder. However, the mean dose of SGAs was about 30% lower in older patients in both diagnostic groups. Regardless of age, patients with a mood disorder were prescribed lower doses of antipsychotics than those with a psychotic disorder. Conclusions: Our data suggest that older patients are prescribed lower antipsychotic dosages primarily when using SGAs. This finding emphasizes the need for dose-finding studies assessing both the efficacy and the safety of antipsychotics in older patients with a psychotic or mood disorder.

Objective: The primary objective of this article is to review the literature regarding the speed of response to antidepressant drugs and potential strategies to accelerate the antidepressant response in new antidepressant-free patients with depression. Based on these data, we try to propose both an effective and safe antidepressant treatment strategy to alleviate depressive symptoms at the earliest opportunity. Data sources: Data were identified by searches of Medline (1966 to September 2009) and references from relevant articles and books. Search terms included depression, antidepressant, predictor, response, onset, acceleration, and augmentation. As our focus was on the acute phase treatment of depression, articles relevant to treatment-resistant depression were excluded. Only articles written in English or Japanese were consulted. Data selection: Studies, reviews, and books pertaining to the treatment of depression with a special regard to accelerating therapeutic effects were selected. Data synthesis: Most of the available treatment guidelines for major depressive disorders recommend the continuous use of antidepressants for 4 to 8. weeks based on the idea of a delayed onset of response to these drugs. Contrary to this conventional belief, the recent data indicate that antidepressants start to exert their effects within 2. weeks and early non-response could predict a subsequent unfavorable outcome. Conclusions: These findings suggest the need of revisiting the timing of an antidepressant switch for early non-responders, whereby switching could be commenced in as early as 2. weeks.

The purpose of the present study was to evaluate changes in metabolic parameters after switching to aripiprazole in Japanese population. In this 1-year observation study, following a switch to aripiprazole, 32 patients with schizophrenia were observed and assessment was done of bodyweight, total cholesterol, triglyceride, serum prolactin level, and corrected QT (QTc) interval. Significant reductions were observed in these parameters other than QTc interval. Given known detrimental metabolic and hormonal effects of some atypical antipsychotics, a switch to aripiprazole may warrant serious consideration also in Asian patients who suffer those side-effects.

Studies were sought that evaluated the prevalence, effectiveness, and safety of pro re nata (p.r.n.) medications in psychiatric practice for which evidence has been scarce despite their wide application. To this end, a systematic literature search was performed using various search engines (last search: October 2012) with cross-referencing. A total of 34 studies were identified: 16 studies on epidemiological usage, 16 retrospective studies on effectiveness/safety as well as reasons, and only two prospective studies on the effectiveness/safety of p.r.n. medications. All the patients studied were inpatients, and the reasons for p.r.n. were acute behavioral dyscontrol in 29 studies. Psychiatric diagnoses and outcome measures to assess effectiveness/safety varied and were described in 27 and 20 studies, respectively. Medications under study included antipsychotics (mainly chlorpromazine, haloperidol, olanzapine, risperidone, or quetiapine), benzodiazepines (mainly diazepam and lorazepam), and antihistamines (mainly diphenhydramine). Altogether, 17 studies reported that p.r.n. medications were effective in psychiatric inpatients. Those two prospective studies targeted solely a child/adolescent population with small sample sizes. Currently available data are limited in number, quality, and scope; there has been only equivocal evidence to guide the choice of p.r.n. medications for psychiatric patients, hence there is a need for more investigations on this important clinical topic.

Background: Large-scale data are still lacking on the relationship between serum prolactin concentration and dopamine D2 receptor occupancy in patients with schizophrenia treated with antipsychotics. Methods: The dataset from 481 subjects (risperidone, N = 172, olanzapine, N= 211, and ziprasidone, N = 98) who participated in Phase 1 of the Clinical Antipsychotic Trials in Intervention Effectiveness (CATIE) was used in the present analysis. Dopamine D2 receptor occupancy levels on the day of the measurement of serum prolactin level were estimated from plasma antipsychotic concentrations. A multivariate general linear model was used to examine effects of clinical and demographic characteristics, including estimated D2 occupancy levels, on serum prolactin concentrations. Individual subjects were divided into two groups, stratified by the presence of hyperprolactinemia. To evaluate the performance of this binary classification, sensitivity, specificity, and accuracy of consecutive cut-off points in the D2 occupancy were calculated. Results: The multivariate general linear model revealed that estimated D2 occupancy levels had significant effects on serum prolactin concentrations while any other variables failed to show significant effects. The cut-off point associated with 0.5 or greater, in both sensitivity and specificity with the greatest accuracy, was 73% (sensitivity, 0.58; specificity, 0.68; accuracy = 0.64) (68-70% for risperidone, 77% for olanzapine, and 55% for ziprasidone.). Conclusion: The threshold for hyperprolactinemia in D2 occupancy may lie somewhat on a lower side of the established therapeutic window with antipsychotics (i.e. 65-80%). This finding highlights the need for the use of the lowest possible dose to avoid this hormonal side effect in the treatment of schizophrenia.

To examine the effect of prolactin-raising antipsychotics on bone mineral density (BMD), data of 164 schizophrenia patients who received ?. 2 dual-energy x-ray absorptiometry scans were analyzed (49.3% men; mean. ±. SD age: 58.5. ±. 11.0. years; duration of treatment: 26.7. ± 13.8. years). Patients were divided into a prolactin-raising antipsychotic (n = 141) or prolactin-sparing (n = 23) group, and time x group interaction was examined using mixed effect model. Although the BMD difference did not reach significance over 3.4. ± 1.6. years, a significant antipsychotic-class vs. time interaction was found (p = 0.011), indicating a negative impact of prolactin-raising antipsychotics on BMD. Large-scale, randomized-controlled data are required to replicate and extend these findings.

Rationale: Ziprasidone is an atypical antipsychotic recommended to be administered twice daily. Objectives: The purpose of this study was to investigate whether occupancy of the dopamine D2/3 receptors by ziprasidone is maintained across a day employing a within subject design. Methods: Positron emission tomography (PET) scans with [11C]- raclopride were performed in 12 patients with schizophrenia while treated with ziprasidone 60 mg twice daily. Each patient completed [11C]- raclopride PET scans at 5, 13 and 23 h after the last dose of ziprasidone. Dopamine D2/3 receptor occupancy was estimated with reference to binding potential data of 44 age- and sex-matched control subjects in the caudate, putamen and ventral striatum. Results: Eleven scans were available at each time point, and the mean occupancies at 5-, 13- and 23-h scans were 66, 39 and 2 % in the putamen; 62, 35 and -6 % in the caudate; and 68, 47 and 11 % in the ventral striatum, respectively. The time-course of receptor occupancy across the regions indicated an occupancy half-life of 8.3 h. The serum level of ziprasidone associated with 50 % D2/3 receptors occupancy was estimated to be 204 nmol/L (84 ng/ml). Prolactin levels were highest at 5-h post-dose and none showed hyperprolactinemia at 23-h scans. Conclusions: The absence of ziprasidone striatal D2/3 receptor binding 23 h after taking 60 mg under steady-state conditions is consistent with its peripheral half-life. The results support our earlier report that ziprasidone 60 mg administered twice daily appears to be the minimal dose expected to achieve therapeutic central dopamine D2/3 receptor occupancy (i.e. 60 %). Clinical Trials Registration: 24-Hour Time Course of Striatal Dopamine D 2 Receptor Occupancy of Ziprasidone: A PET Study, www.clinicaltrials.gov/ct2/show/NCT00818298, NCT00818298

Introduction: Antipsychotic drugs exert antipsychotic effects by blocking dopamine D2 receptors in the treatment of schizophrenia. However, effects of D2 receptor blockade on neurocognitive function still remain to be elucidated. The objective of this analysis was to evaluate impacts of estimated dopamine D2 receptor occupancy with antipsychotic drugs on several domains of neurocognitive function in patients with schizophrenia in the Clinical Antipsychotic Trials in Intervention Effectiveness (CATIE) trial. Methods: The dataset from the CATIE trial was used in the present analysis. Data were extracted from 410 subjects who were treated with risperidone, olanzapine, or ziprasidone, received assessments for neurocognitive functions (verbal memory, vigilance, processing speed, reasoning, and working memory) and psychopathology, and provided plasma samples for the measurement of plasma antipsychotic concentrations. D2 receptor occupancy levels on the day of neurocognitive assessment were estimated from plasma antipsychotic concentrations, using population pharmacokinetic analysis and our recently developed model. A multivariate general linear model was used to examine effects of clinical and demographic characteristics, including estimated D2 occupancy levels, on neurocognitive functions. Results: D2 occupancy levels showed significant associations with the vigilance and the summary scores. Neurocognitive functions, including vigilance, were especially impaired in subjects who showed D2 receptor occupancy level of >77%. Discussion: These findings suggest a nonlinear relationship between prescribed antipsychotic doses and overall neurocognitive function and vigilance. This study shows that D2 occupancy above approximately 80% not only increases the risk for extrapyramidal side effects as consistently reported in the literature but also increases the risk for cognitive impairment.

Background: It still remains unclear as to how to counteract antipsychotic polypharmacy that remains controversial but common. The objective of this study was to synthesize the clinical evidence to reduce antipsychotic polypharmacy (i.e. use of multiple antipsychotics) in schizophrenia. Methods: A literature search was performed to identify clinical trials that attempted to reduce antipsychotic polypharmacy in patients with schizophrenia by any form of systematic intervention using PubMed as well as MEDLINE, EMBASE, and PsycINFO (last search: June 2012). The search terms included "antipsychotics" and "polypharmacy". Cross-referencing was also performed. Results: The literature search identified 17 studies. Only 3 studies (1 randomized controlled trial and 2 open-label trials) were found that systematically switched antipsychotic polypharmacy to monotherapy. In two of them, more than two thirds of the subjects successfully completed the switch (40/58, 69.0%; 34/44, and 77.3%, respectively) while less than half the subjects tolerated it in the other study (6/14 and 42.9%) although the sample size was very small. On the other hand, 14 studies that examined impacts of interventions have physicians refrain from antipsychotic polypharmacy. While a modest intervention with educational approach alone was effective in three of the five articles, a more assertive intervention that directly cautioned physicians on the use of polypharmacy was effective in 10 of 12 articles. Conclusion: The literature search revealed the paucity of the data. Careful switching from polypharmacy to monotherapy seems feasible in a majority of patients with schizophrenia. Assertive interventions, rather than passive educational approaches alone, appear more effective in reducing antipsychotic polypharmacy.

Introduction: While patients with schizophrenia are often treated with psychotropic polypharmacy, how and when polypharmacy begins is not well documented. Methods: A systematic chart review of 300 patients, 100 of whom were psychotropic-free prior to their first visit, was conducted to examine 2-year longitudinal prescription patterns of concomitant psychotropics, in addition to a primary antipsychotic. Results: Overall polypharmacy occurred in 79% patients, with 2-year rates of the use of hypnotics, benzodiazepine derivative anxiolytics, anticholinergic drugs, antidepressants, and mood stabilizers were 56.7, 49.7, 38.3, 21.3, and 14.0%, respectively. Once polypharmacy had started, it was continued until their final visit in >70% of the patients. In a subgroup of 100 psychotropic-free patients, mood stabilizers, antidepressants, anticholinergic antiparkinsonian drugs, anxiolytics, and hypnotics were initiated after 2.3, 2.3, 2.1, 1.6, and 1.5 antipsychotics had been prescribed, respectively (mean duration before the introduction of a concomitant drug in days: 17.7, 121.6, 86.4, 32.1, and, 57.7, respectively). Conclusion: Routine practice deviates significantly from algorithms - with polypharmacy often being initiated early, often a without trial of other options, and once started commonly stays.

Objective: While the Kraepelinian dichotomy explicitly distinguishes between schizophrenia and bipolar disorder, it remains unclear as to whether a deficit form of bipolar disorder exists. Method: We conducted a study to investigate the prevalence rate of the deficit form of bipolar disorder; the criteria of which were basically adopted by the original proposal for schizophrenia that described the predominance of negative symptoms for over a year. Moreover, we presented a series of cases with deficit bipolar disorder to characterize its clinical pictures in detail. Results: Consecutive outpatients who visited one psychiatric hospital in Tokyo, Japan in March 2007 were evaluated cross-sectionally. Additionally, medical charts of inpatients who were hospitalized in the same hospital between April 2006 and March 2007 were also thoroughly reviewed. Of 494 patients, 7 patients (1.4%; 10.9% of 64 bipolar cases) fulfilled the criteria for bipolar disorder with deficit syndrome. Seven deficit cases had a mean±SD age of 61±5 year-old with the age at onset being 25±8 year-old. In addition to pervasive negative symptoms, they exhibited evidence of cognitive impairments close to the magnitude of what is usually noted in schizophrenia (i.e. a mean±SD total IQ score of 80±9 in the Wechsler Adult Intelligence Scale and 0.4±0.5 in the Wisconsin Card Sorting Test, categories achieved). Conclusion: Although preliminary, the evidence on deficit status in patients with bipolar disorder that we found in this study appears more consistent with recent evidence and challenges the Kraepelinian dichotomy that reserves deficit status solely to schizophrenia patients.

Background: Patients coping methods to palliate side effects of antidepressants have not been reported in the literature. Methods: Through an Internet survey, 856 participants who were diagnosed with depression and receiving antidepressants were recruited to report on the methods of coping with side effects. They were asked which side effect(s) they experienced and to write freely about the way they tried to counteract these effects. We classified active coping methods into the following sub-types: adjustment of prescriptions, additional medication, complementary therapy, consultation with physicians, and daily relief. Results: The prevalence of active coping differed across side effects (from 26.7%, sexual dysfunction, to 89.5%, dry mouth). Events with a lower percentage of active coping were more likely to be managed with adjustment of prescriptions: (sexual dysfunction, 41.9%; fatigue, 36.8%; sweating, 20.0%; tremor, 42.5%; and somnolence, 31.8%). Further, a strong negative correlation was found between the percentage of participants reporting an adjustment of prescription and that reporting an active coping (r=-0.907, p<0.001). The daily relief sub-type contained a variety of strategies, including negative methods such as vomiting for nausea and weight gain and drinking alcohol for insomnia. Limitations: Sampling of subjects were biased due to an Internet survey and diagnosis of depression and experience of side effects were self-reported. Conclusion: Patients with depression use various ways in alleviating antidepressants side effects. Some effects such as sexual dysfunction and fatigue may not be amenable to subjective coping efforts and others are sometimes managed inappropriately, which warrants a prudent attention.

The 3rd Schizophrenia International Research Society Conference was held in Florence, Italy, April 14-18, 2012 and this year had as its emphasis, "The Globalization of Research". Student travel awardees served as rapporteurs for each oral session and focused their summaries on the most significant findings that emerged and the discussions that followed. The following report is a composite of these summaries. We hope that it will provide an overview for those who were present, but could not participate in all sessions, and those who did not have the opportunity to attend, but who would be interested in an update on current investigations ongoing in the field of schizophrenia research.