Comparative effectiveness of atypical antipsychotics in schizophrenia: what have real-world trials taught us?

Tricyclic antipsychotics and antidepressants can inhibit α5-containing GABAA receptors by two distinct mechanisms

Background and Purpose

Many psychotherapeutic drugs, including clozapine, display polypharmacology and act on GABA_A receptors. Patients with schizophrenia show alterations in function, structure and molecular composition of the hippocampus, and a recent study demonstrated aberrant levels of hippocampal α5 subunit‐containing GABA_A receptors. The purpose of this study is to investigate the effects of tricyclic compounds on α5 subunit‐containing receptor subtypes.

Experimental Approach

Functional studies of effects by seven antipsychotic and antidepressant medications were performed in several GABA_A receptor subtypes by two‐electrode voltage‐clamp electrophysiology using Xenopus laevis oocytes. Computational structural analysis was employed to design mutated constructs of the α5 subunit, probing a novel binding site. Radioligand displacement data complemented the functional and mutational findings.

Key Results

The antipsychotic drugs clozapine and chlorpromazine exerted functional inhibition on multiple GABA_A receptor subtypes, including those containing α5‐subunits. Based on a chlorpromazine binding site observed in a GABA‐gated bacterial homologue, we identified a novel site in α5 GABA_A receptor subunits and demonstrate differential usage of this and the orthosteric sites by these ligands.

Conclusion and Implications

Despite high molecular and functional similarities among the tested ligands, they reduce GABA currents by differential usage of allosteric and orthosteric sites. The chlorpromazine site we describe here is a new potential target for optimizing antipsychotic medications with beneficial polypharmacology. Further studies in defined subtypes are needed to substantiate mechanistic links between the therapeutic effects of clozapine and its action on certain GABA_A receptor subtypes.

New dual 5-HT1A and 5-HT7 receptor ligands derived from SYA16263

We have previously reported that dual 5-HT_1A and 5-HT₇ receptor ligands might find utility as treatment options for various CNS related conditions including cognitive and anxiolytic impairments. We have also more recently reported that SYA16263 has antipsychotic-like properties with an absence of catalepsy in animal models ascribed to its ability to recruit β-arrestin to the D₂ receptor. However, SYA16263 also binds with very high affinity to 5-HT_1AR (Ki = 1.1 nM) and a moderate affinity at 5-HT₇R (Ki = 90 nM). Thus, it was of interest to exploit its pharmacophore elements in designing new dual receptor ligands. Using SYA16263 as the lead molecule, we have conducted a limited structure-affinity relationship (SAFIR) study by modifying various structural elements in the arylalkyl moiety, resulting in the identification of a new dual 5-HT_1AR and 5-HT₇R ligand, 6-chloro-2-methyl-2-(3-(4-(pyridin-2-yl)piperazin-1-yl)propyl)-2,3-dihydro-1H-inden-1-one (21), which unlike SYA16263, has a sub-nanomolar (5-HT_1AR, Ki = 0.74 nM) and a low nanomolar (5-HT₇R, Ki = 8.4 nM) affinity for these receptors. Interestingly, 21 is a full agonist at 5-HT_1AR and antagonist at the 5-HT₇R, functional characteristics which point to its potential as an antidepressant agent.

Influence of crystal packing on the thermal properties of cocrystals and cocrystal solvates of olanzapine: insights from computations

A multicomponent supramolecular host with adaptive guest accommodation abilities is observed in the cocrystal solvates of the olanzapine–hydroquinone system.

Insulin resistance induced by olanzapine and other second-generation antipsychotics in Chinese patients with schizophrenia: a comparative review and meta-analysis

PURPOSE

This systematic review aimed to determine whether olanzapine is more likely than other second-generation antipsychotics (SGAs) to induce insulin resistance in patients with schizophrenia in China.

METHODS

We reviewed all randomized controlled trials on insulin resistance and metabolic abnormalities caused by SGAs in the PubMed, China National Knowledge Infrastructure (CNKI), VIP, and Wanfang databases. Retrieved articles were published on or before December 2018. Meta-analysis was performed to determine the effect size of the treatment on the insulin resistance index (IRI), fasting blood glucose (FBG), and fasting insulin (FINS).

RESULTS

Forty studies (3725 participants in total) were included. All studies contained data suitable for comparing aripiprazole vs. olanzapine, ziprasidone vs. olanzapine, and risperidone vs. olanzapine. Patients treated with olanzapine had higher IRI, FBG, and FINS levels than did patients treated with aripiprazole, ziprasidone, or risperidone, with significant differences (aripiprazole vs. olanzapine: FBG: standardized mean difference [SMD] = 0.72, 95% confidence interval [95%CI] - 0.82, - 0.61; FINS: SMD = - 0.8, 95%CI - 1.00, - 0.61; IRI: SMD = - 0.80, 95%CI - 0.99, - 0.61; ziprasidone vs. olanzapine: FBG: SMD = - 1.19, 95%CI - 1.30, - 1.08; FINS: SMD = - 0.66, 95%CI - 0.85, - 0.47; IRI: SMD = - 0.71, 95%CI - 0.88, - 0.55; risperidone vs. olanzapine: FBG: SMD = - 0.17, 95%CI - 0.34, - 0.00).

CONCLUSIONS

Existing data suggest that olanzapine is associated with a significantly greater risk of IRI, FBG, and FINS, while other agents are associated with relatively lower risks. Thus, olanzapine is more likely to induce insulin resistance than are other SGAs in schizophrenic patients in China.

Association between COMT gene polymorphisms, clinical symptoms, and cognitive functions in Han Chinese patients with schizophrenia

AIM

Catechol-O-methyltransferase (COMT) gene variants may be involved in the pathogenesis of psychotic symptoms, and associated especially with negative symptom in schizophrenia, but their roles in cognitive function and treatment response remain unclear. The aim of this study was to explore the association between COMT gene polymorphisms, clinical symptoms (including cognitive function), and treatment response to antipsychotic medications in patients with schizophrenia.

PATIENTS AND METHODS

A total of 200 Han Chinese inpatients with schizophrenia were recruited in accordance with Diagnostic and Statistical Manual of Mental Disorders, 4th ed. (DSM-IV). In total, 96 of them completed assessments at baseline and after 8 weeks of antipsychotic treatment. Clinical symptoms were assessed using the Positive And Negative Syndrome Scale (PANSS), and cognitive function was evaluated using the Verbal Fluency Test, Trail Making Test A-B, Stroop Color-Word Test, and Wisconsin Card Sorting Test. Two single nucleotide polymorphisms, rs4680 and rs165599, on the COMT gene were genotyped.

RESULTS

At baseline, we found no significant genotypic association between rs4680 and clinical symptoms or cognitive function. After 8 weeks of antipsychotic treatment, compared with patients with GG genotype, patients with AA/AG genotypes at rs4680 showed significantly higher scores on PANSS total, both at baseline and at the end of 8 weeks, especially in negative and general psychopathology symptoms. Patients with GG at rs165599 scored significantly higher on the Stroop test, suggesting better cognitive performance after 8 weeks of treatment. No significant association was found between rs165599 genotype and psychiatric symptoms as assessed by the PANSS and cognitive function tests at baseline.

CONCLUSION

Our findings suggest that the COMT gene polymorphisms may influence the response to antipsychotic treatment in Han Chinese patients with schizophrenia.

ECT augmentation of clozapine for clozapine-resistant schizophrenia: A meta-analysis of randomized controlled trials

Treatment-resistant schizophrenia (TRS) is common and debilitating. A subgroup of patients even has clozapine-resistant schizophrenia (CRS). We aimed to evaluate the efficacy and safety of electroconvulsive therapy (ECT) augmentation of clozapine for CRS. Systematic literature search of randomized controlled trials (RCTs) reporting on ECT augmentation of clozapine in CRS. Co-primary outcomes included symptomatic improvement at post-ECT assessment and study endpoint. Eighteen RCTs (n = 1769) with 20 active treatment arms were identified and meta-analyzed. Adjunctive ECT was superior to clozapine regarding symptomatic improvement at post-ECT assessment (Standardized Mean Difference (SMD) = -0.88, 95% Confidence Interval (CI): -1.33 to -0.44; I² = 86%, P = 0.0001) and endpoint assessment (SMD: -1.44, 95%CI: -2.05 to -0.84; I² = 95%, P < 0.00001), separating as early as week 1-2 (SMD = -0.54, 95%CI: -0.88 to -0.20; I² = 77%, P = 0.002). Adjunctive ECT was also superior regarding study-defined response at post-ECT assessment (53.6% vs. 25.4%, Risk Ratio (RR) = 1.94, 95%CI: 1.59-2.36; I² = 0%, P < 0.00001, number-needed-to-treat (NNT) = 3, 95%CI: 3-5) and endpoint assessment (67.7% vs. 41.4%, RR = 1.66, 95%CI: 1.38-1.99; I² = 47%, P < 0.00001, NNT = 4, 95%CI: 3-8), and remission at post-ECT assessment (13.3% vs. 3.7%, RR = 3.28, 95%CI: 1.80-5.99; I² = 0%, P = 0.0001, NNT = 13, 95%CI: 6-100) and endpoint assessment (23.6% vs. 13.3%, RR = 1.80, 95%CI: 1.39 to 2.35; I² = 5%, P < 0.0001, NNT = 14, 95%CI: 6-50). Patient-reported memory impairment (24.2% vs. 0%; RR = 16.10 (95%CI: 4.53-57.26); I² = 0%, P < 0.0001, number-needed-to-harm (NNH) = 4, 95%CI: 2-14) and headache (14.5% vs 1.6%; RR = 4.03 (95%CI: 1.54-10.56); I² = 0%, P = 0.005, NNH = 8, 95%CI: 4-50) occurred more frequently with adjunctive ECT. No significant group differences were found regarding discontinuation and other adverse effects. Despite increased frequency of self-reported memory impairment and headache, ECT augmentation of clozapine is a highly effective and relatively safe treatment for CRS.

REGISTRATION NUMBER

CRD42018089959.

Immune activation in lactating dams alters sucklings' brain cytokines and produces non-overlapping behavioral deficits in adult female and male offspring: A novel neurodevelopmental model of sex-specific psychopathology

Early immune activation (IA) in rodents, prenatal through the mother or early postnatal directly to the neonate, is widely used to produce behavioral endophenotypes relevant to schizophrenia and depression. Given that maternal immune response plays a crucial role in the deleterious effects of prenatal IA, and lactation is a critical vehicle of immunological support to the neonate, we predicted that immune activation of the lactating dam will produce long-term abnormalities in the sucklings. Nursing dams were injected on postnatal day 4 with the viral mimic poly-I:C (4mg/kg) or saline. Cytokine assessment was performed in dams' plasma and milk 2h, and in the sucklings' hippocampus, 6h and 24h following poly-I:C injection. Male and female sucklings were assessed in adulthood for: a) performance on behavioral tasks measuring constructs considered relevant to schizophrenia (selective attention and executive control) and depression (despair and anhedonia); b) response to relevant pharmacological treatments; c) brain structural changes. Maternal poly-I:C injection caused cytokine alterations in the dams' plasma and milk, as well as in the sucklings' hippocampus. Lactational poly-I:C exposure led to sex-dimorphic (non-overlapping) behavioral abnormalities in the adult offspring, with male but not female offspring exhibiting attentional and executive function abnormalities (manifested in persistent latent inhibition and slow reversal) and hypodopaminergia, and female but not male offspring exhibiting despair and anhedonia (manifested in increased immobility in the forced swim test and reduced saccharine preference) and hyperdopaminergia, mimicking the known sex-bias in schizophrenia and depression. The behavioral double-dissociation predicted distinct pharmacological profiles, recapitulating the pharmacology of negative/cognitive symptoms and depression. In-vivo imaging revealed hippocampal and striatal volume reductions in both sexes, as found in both disorders. This is the first evidence for the emergence of long-term behavioral and brain abnormalities after lactational exposure to an inflammatory agent, supporting a causal link between early immune activation and disrupted neuropsychodevelopment. That such exposure produces schizophrenia- or depression-like phenotype depending on sex, resonates with notions that risk factors are transdiagnostic, and that sex is a susceptibility factor for neurodevelopmental psychopathologies.

Potential Role of Patients' CYP3A-Status in Clozapine Pharmacokinetics

BACKGROUND

The atypical antipsychotic clozapine is effective in treatment-resistant schizophrenia; however, the success or failure of clozapine therapy is substantially affected by the variables that impact the clozapine blood concentration. Thus, elucidating the inter-individual differences in clozapine pharmacokinetics can facilitate the personalized therapy.

METHODS

Since a potential role in clozapine metabolism is assigned to CYP1A2, CYP2C19, CYP2D6 and CYP3A enzymes, the association between the patients' CYP status (CYP genotypes, CYP expression) and clozapine clearance was evaluated in 92 psychiatric patients.

RESULTS

The patients' CYP2C19 or CYP2D6 genotypes and CYP1A2 expression seemed to have no effect on clozapine serum concentration, whereas CYP3A4 expression significantly influenced the normalized clozapine concentration (185.53±56.53 in low expressers vs 78.05±29.57 or 66.52±0.25 (ng/mL)/(mg/kg) in normal or high expressers, P<.0001), in particular that the patients expressed CYP1A2 at a relatively low level. The functional CYP3A5*1 allele seemed to influence clozapine concentrations in those patients who expressed CYP3A4 at low levels. The dose requirement for the therapeutic concentration of clozapine was substantially lower in low CYP3A4 expresser patients than in normal/high expressers (2.18±0.64 vs 4.98±1.40 mg/kg, P<.0001). Furthermore, significantly higher plasma concentration ratios of norclozapine/clozapine and clozapine N-oxide/clozapine were observed in the patients displaying normal/high CYP3A4 expression than in the low expressers.

CONCLUSION

Prospective assaying of CYP3A-status (CYP3A4 expression, CYP3A5 genotype) may better identify the patients with higher risk of inefficiency or adverse reactions and may facilitate the improvement of personalized clozapine therapy; however, further clinical studies are required to prove the benefit of CYP3A testing for patients under clozapine therapy.

Experimental treatment of antipsychotic-induced movement disorders

Antipsychotic drugs are extensively prescribed for the treatment of schizophrenia and other related psychiatric disorders. These drugs produced their action by blocking dopamine (DA) receptors, and these receptors are widely present throughout the brain. Therefore, extended antipsychotic use also leads to severe extrapyramidal side effects. The short-term effects include parkinsonism and the later appearing tardive dyskinesia. Currently available treatments for these disorders are mostly symptomatic and insufficient, and are often linked with a number of detrimental side effects. Antipsychotic-drug-induced tardive dyskinesia prompted researchers to explore novel drugs with fewer undesirable extrapyramidal side effects. Preclinical studies suggest a role of 5-hydroxytryptamine (serotonin)-1A and 2A/2C receptors in the modulation of dopaminergic neurotransmission and motivating a search for better therapeutic strategies for schizophrenia and related disorders. In addition, adjunctive treatment with antioxidants such as vitamin E, red rice bran oil, and curcumin in the early phases of illness may prevent additional oxidative injury, and thus improve and prevent further possible worsening of related neurological and behavioral deficits in schizophrenia. This review explains the role of serotonergic receptors and oxidative stress, with the aim of providing principles for prospect development of compounds to improve therapeutic effects of antischizophrenic drugs.

Antipsychotic medications and extreme weight gain in two health systems

OBJECTIVE

We conducted this study to investigate the rate of clinically important, extreme weight gain (EWG; ≥7% body weight gain) among all second generation antipsychotic (SGA) users in two large health care systems in the United States.

STUDY DESIGN

Retrospective observational cohort study.

METHODS

We used electronic medical record databases of two health systems to identify adults aged 18-79 years who from 1 January 2004 to 31 December 2011 had initiated a SGA medication. All patients had to have a minimum of two weight measures in the medical record: (1) one or more weights in the 180-day pre-treatment (baseline) period; and (2) one or more weights in the first year after initiating SGA treatment.

RESULTS

We found that EWG occurred in 7.7-17.0% of SGA users. At one year, the average weight gain was nearly 10kg among SGA users who experienced EWG. Olanzapine was the SGA most commonly associated with EWG with a rate of 17.0 per 100 users [95% confidence interval (CI): 14.2-20.5], while ziprasidone was least commonly associated with EWG (7.7 per 100 users; 95% CI: 4.6-13.0).

CONCLUSIONS

We found that clinically-important weight gain was common after the initiation of SGA treatment, and the EWG phenotype was easily identifiable within electronic medical records. There was significant heterogeneity in the rate of EWG across SGA medications. Weight gains of this magnitude are likely to have adverse health consequences and there is a significant unmet opportunity for physicians to identify these events and mitigate the harms of SGA use.

Remission, response, and relapse rates in patients with acute schizophrenia treated with olanzapine monotherapy or other atypical antipsychotic monotherapy: 12-month prospective observational study

PURPOSE

To compare the rates of antipsychotic response, remission, and relapse in patients with schizophrenia treated with olanzapine or other antipsychotics in usual clinical care in Japan.

PATIENTS AND METHODS

This analysis of a 12-month, prospective, noninterventional study examined outcomes for 1,089 inpatients and outpatients with schizophrenia who initiated antipsychotic monotherapy. All treatment decisions, including medication choice, were left to the discretion of the treating physician. The rates of treatment response, relapse, and 6-month sustained remission were compared between olanzapine monotherapy (OLZ) and other anti-psychotic monotherapy (OAN), and between OLZ and other atypical antipsychotic monotherapy (OAT). Visit-wise comparisons of treatment response and remission were examined using repeated-measures logistic regressions. Propensity scores were used to control for potential baseline differences between groups.

RESULTS

Response rates were higher for OLZ patients and relapse rates were consistently lower for OLZ patients, however the differences were not statistically significant. Rates of 6-month sustained remission were significantly higher for OLZ than OAN patients (P=0.032) and for OLZ than OAT patients (P=0.041). An exploratory analysis of OLZ and OAN comparison found outpatients treated with OLZ or OAN had similar sustained remission rates (OLZ: 22.2%, OAN: 22.8%), while inpatients treated with OLZ had significantly higher sustained remission rates than inpatients treated with OAN (OLZ: 17.1%, OAN: 6.6%, odds ratio [95% confidence interval] =3.54 [2.00-6.25]).

CONCLUSION

In usual care in Japan, treating the acute symptoms of schizophrenia with olanzapine was not found to be significantly different for response and relapse rates; however, treatment with olanzapine was found to have significantly greater sustained remission rates than treatment with other antipsychotics. In the inpatient setting, where patients tend to be more severe and difficult to manage, olanzapine treatment may lead to higher sustained remission rates than other antipsychotics.

Clozapine for treatment-resistant bipolar disorder: a systematic review

OBJECTIVE

To evaluate the efficacy and safety of clozapine for treatment-resistant bipolar disorder (TRBD).

METHODS

A systematic review of randomized controlled studies, open-label prospective studies, and retrospective studies of patients with TRBD was carried out. Interventions included clozapine monotherapy or clozapine combined with other medications. Outcome measures were efficacy and adverse drug reactions (ADRs).

RESULTS

Fifteen clinical trials with a total sample of 1,044 patients met the inclusion criteria. Clozapine monotherapy or clozapine combined with other treatments for TRBD was associated with improvement in: (i) symptoms of mania, depression, rapid cycling, and psychotic symptoms, with many patients with TRBD achieving a remission or response; (ii) the number and duration of hospitalizations, the number of psychotropic co-medications, and the number of hospital visits for somatic reasons for intentional self-harm/overdose; (iii) suicidal ideation and aggressive behavior; and (iv) social functioning. In addition, patients with TRBD showed greater clinical improvement in long-term follow-up when compared with published schizophrenia data. Sedation (12%), constipation (5.0%), sialorrhea (5.2%), weight gain (4%), and body ache/pain (2%) were the commonly reported ADRs; however, these symptoms but did not usually require drug discontinuation. The percentage of severe ADRs reported, such as leukopenia (2%), agranulocytosis (0.3%), and seizure (0.5%), appeared to be lower than those reported in the published schizophrenia literature.

CONCLUSION

The limited current evidence supports the concept that clozapine may be both an effective and a relatively safe medication for TRBD.

Health care resource utilization and direct medical costs for patients with schizophrenia initiating treatment with atypical versus typical antipsychotics in Tianjin, China

Background

It is uncertain whether the extra acquisition costs of atypical antipsychotics over typical antipsychotics are offset by their other reduced resource use especially in hospital services in China. This study compared the psychiatric-related health care resource utilization and direct medical costs for patients with schizophrenia initiating atypical or typical antipsychotics in Tianjin, China.

Methods

Data were obtained from the Tianjin Urban Employee Basic Medical Insurance database (2008–2010). Adult patients with schizophrenia with ≥1 prescription for antipsychotics after ≥90-day washout and 12-month continuous enrollment after first prescription was included. Psychiatric-related resource utilization and direct medical costs of the atypical and typical cohorts were estimated during the 12-month follow-up period. Logistic regressions, ordinary least square (OLS), and generalized linear models (GLM) were employed to estimate differences of resource utilization and costs between the two cohorts. One-to-one propensity score matching was conducted as a sensitivity analysis.

Results

1131 patients initiating either atypical (N = 648) or typical antipsychotics (N = 483) were identified. Compared with the typical cohort, the atypical cohort had a lower likelihood of hospitalization (45.8% vs. 56.7%, P < 0.001; adjusted OR: 0.58, P < 0.001) over the follow-up period. Medication costs for the atypical cohort were higher than the typical cohort ($438 vs. $187, P < 0.001); however, their non-medication medical costs were significantly lower ($1223 vs. $1704, P < 0.001). The total direct medical costs were similar between the atypical and typical cohorts before ($1661 vs. $1892, P = 0.100) and after matching ($1711 vs. 1868, P = 0.341), consistent with the results from OLS and GLM models for matched cohorts.

Conclusions

The atypical cohort had similar total direct medical costs compared to the typical cohort. Higher medication costs associated with atypical antipsychotics were offset by a reduction in non-medication medical costs, driven by fewer hospitalizations.

Dried blood spot testing: a novel approach for the therapeutic drug monitoring of ziprasidone-treated patients

Background: A novel analytical approach, based on dried blood spot (DBS) testing, has been developed, validated and applied for the first time to the analysis of ziprasidone (ZPR) for the therapeutic drug monitoring (TDM) of schizophrenic patients. DBS represent a more feasible but reliable matrix, alternative to blood and plasma. Methods: The assays were carried out using an HPLC method with native fluorescence. Blood drops were applied to DBS cards and dried by microwaves, an internal standard solution was added to the DBS and 5-mm punches were cut out for analysis. ZPR was extracted from DBS with methanol, giving good extraction yields, precision and selectivity results. Results: The method was applied with satisfactory results to DBS samples from psychiatric patients to determine ZPR levels for therapy optimization. Conclusion: This innovative methodology provides reliable and significant TDM information, with important advantages over classical blood sampling in terms of collection, storage and processing.

Polypharmacy with antipsychotic drugs in patients with schizophrenia: trends in multiple health care systems

PURPOSE

Patterns of pharmacologic treatment in U.S. outpatients with schizophrenia across multiple health care settings were investigated.

METHODS

Antipsychotic drug utilization by patients with schizophrenia and related disorders was analyzed using data on 119,662 patients served by the Veterans Affairs (VA) health care system in fiscal years 2005-09, data on 5,440 enrollees in two health maintenance organizations (HMOs) in 2002-09, and National Ambulatory Medical Care Survey (NAMCS) data reflecting the experience of 17.6 million U.S. residents seeking care outside federal systems during the same eight-year period. Polypharmacy was defined as the use of more than one antipsychotic agent during one year (in the VA sample) or one week (in the HMO and NAMCS samples). The association of polypharmacy with hospital admissions was assessed via multivariable logistic regression.

RESULTS

Rates of antipsychotic use in the VA sample ranged from 74% to 78%, with lower and more variable rates in the NAMCS sample (69-84%) and the HMO sample (22-67%). VA patients were found to have lower polypharmacy rates (20-22%) than patients in the HMO and NAMCS samples (19-31%). In all samples evaluated, polypharmacy was associated with an increased likelihood of hospital admission (odds ratio range, 1.4-2.4).

CONCLUSION

A multisystem study revealed that antipsychotic use among patients with schizophrenia varied substantially among health care systems and that nearly one fifth of patients with schizophrenia or other psychotic disorders in most of the health care systems experienced antipsychotic polypharmacy.

Clozapine: a review of clinical practice guidelines and prescribing trends

BACKGROUND

Clozapine effectiveness in the treatment of refractory schizophrenia has been sustained by published evidence in the last two decades, despite the introduction of safer options.

DISCUSSION

Current clinical practice guidelines have strongly recommended the use of clozapine in treatment-resistant schizophrenia, but prescribing trends do not appear to have followed such recommendations. Clozapine is still underutilized especially in patients at risk of suicide. It seems that physicians are hesitant in prescribing clozapine due to concerns about serious adverse effects. Recent reports have highlighted the need to inform health professionals about the benefits of treating patients with clozapine and have voiced concerns about the underutilization of clozapine especially in patients at risk of suicide.

SUMMARY

Guidelines and prescribing patterns reported in various countries worldwide are discussed. Suggestions on how to optimize clozapine utilization have been published but more efforts are needed to properly inform and support prescribers' practices.

Is elevated norepinephrine an etiological factor in some cases of schizophrenia?

A number of hypotheses have been put forth regarding the etiology of schizophrenia, including the dopamine hypothesis, NMDA receptor hypofunction hypothesis, and others. A lesser known theory is that elevated noradrenergic signaling plays a causative role in the disease. This paper briefly re-examines the merits of this hypothesis, including as it relates to some recently published studies. Several lines of evidence are investigated, including: endogenous level studies of norepinephrine (NE); modulation of the disease by noradrenergic drugs; association of the disease with bipolar disorder and hypertension, since these latter two conditions may involve elevated NE transmission; and effects of psychological stress on the disease, since stress can produce elevated release of NE. For many of these lines of evidence, their relationship with prepulse inhibition of startle is examined. A number of these studies support the hypothesis, and several suggest that elevated NE signaling plays a particularly prominent role in the paranoid subtype of schizophrenia. If the hypothesis is correct for some persons, conventional pharmaceutical treatment options, such as use of atypical antipsychotics (which may themselves modulate noradrenergic signaling), may be improved if selective NE transmission modulating agents are added to or even substituted for these conventional drugs.

Does participation in a weight control program also improve clinical and functional outcomes for Chinese patients with schizophrenia treated with olanzapine?

OBJECTIVES

This study examined whether participation in a weight control program (WCP) by patients with schizophrenia treated with olanzapine was also associated with improvements in clinical and functional outcomes.

METHODS

A post-hoc analysis was conducted using data from the Chinese subgroup (n=330) of a multi-country, 6-month, prospective, observational study of outpatients with schizophrenia who initiated or switched to oral olanzapine. At study entry and monthly visits, participants were assessed with the Clinical Global Impression of Severity, and measures of patient insight, social activities, and work impairment. The primary comparison was between the 153 patients who participated in a WCP at study entry (n=93) or during the study (n=60) and the 177 patients who did not participate in a weight control program (non-WCP). Mixed Models for Repeated Measures with baseline covariates were used to compare outcomes over time. Kaplan-Meier survival analysis was used to assess time to response.

RESULTS

Participants had a mean age of 29.0 years and 29.3 years, and 51.0% and 57.6% were female for WCP and non-WCP groups, respectively. Average initiated daily dose for olanzapine was 9.5±5.4 mg. WCP participants gained less weight than non-participants (3.9 kg vs 4.9 kg, P=0.03) and showed statistically significant better clinical and functional outcomes: greater improvement in illness severity (-2.8 vs -2.1, P<0.001), higher treatment response rates (94.1% vs 80.9%, P<0.001), shorter time to response (P<0.001), and greater improvement in patients' insight (P<0.001). Patients who enrolled in a WCP during the study had greater initial weight gain than those who enrolled at baseline (P<0.05), but similar total weight gain.

CONCLUSION

Participation in a WCP may not only lower the risk of clinically significant weight gain in olanzapine-treated patients, but may also be associated with additional clinical and functional benefits.

Nonhuman primates: translational models for predicting antipsychotic-induced movement disorders

Repeated haloperidol treatment administered to nonhuman primates (NHPs) over several months or even years leads to the gradual appearance of drug-induced dystonic reactions in the orofacial region (mouth opening, tongue protrusion or retraction, bar biting) and in the whole body (writhing of the limbs and trunk, bar grasping). The propensity of antipsychotics to induce dystonia in NHPs is not correlated with their propensity to induce catalepsy in rodents, suggesting that the two types of effects are dissociated and may represent distinct aspects of the extrapyramidal symptoms induced by antipsychotics. In view of the clear homology to clinically observed phenomena, antipsychotic-induced dystonias in antipsychotic-primed NHPs would appear to possess a high degree of translational validity. These NHP phenomena could therefore serve as a useful model for predicting the occurrence of similar abnormal movements with novel substances developed for the treatment of schizophrenia or other psychotic disorders. Moreover, the NHP dystonia model could possibly serve as a biomarker for substances that will eventually cause tardive dyskinesia in patients.

Antipsychotic response in first-episode schizophrenia: efficacy of high doses and switching

Clinicians treating schizophrenia routinely employ high doses and/or antipsychotic switching to achieve response. However, little is actually known regarding the value of these interventions in early schizophrenia. Data were gathered from a treatment algorithm implemented in patients with first-episode schizophrenia that employs two antipsychotic trials at increasing doses before clozapine. Patients were initially treated with either olanzapine or risperidone across three dose ranges, (low, full, high), and in the case of suboptimal response were switched to the alternate antipsychotic. We were interested in the value of (a) high dose treatment and (b) antipsychotic switching. A total of 244 patients were evaluated, with 74.5% (184/244) responsive to Trial 1, and only 16.7% (10/60) responsive to Trial 2. Percentage of response for subjects switched from olanzapine to risperidone was 4.0% (1/25) vs. 25.7% (9/35) for those switched from risperidone to olanzapine. High doses yielded a 15.5% response (14.6% for risperidone vs. 16.7% for olanzapine).The present findings concur with other research indicating that response rate to the initial antipsychotic trial in first-episode schizophrenia is robust; thereafter it declines notably. In general, the proportion of responders to antipsychotic switching and high dose interventions was low. For both strategies olanzapine proved superior to risperidone, particularly in the case of antipsychotic switching (i.e. risperidone to olanzapine vs. vice versa). It remains to be established whether further antipsychotic trials are associated with even greater decrements in rate of response. Findings underscore the importance of moving to clozapine when treatment resistance has been established.

The personal, societal, and economic burden of schizophrenia in the People's Republic of China: implications for antipsychotic therapy

BACKGROUND

This article describes the personal, societal, and economic burden attributable to schizophrenia in the People's Republic of China and highlights the potential for effective outpatient treatment to reduce this burden given recent changes in the Chinese health care system. The importance of effective antipsychotic therapy in reducing the burden of schizophrenia is also examined.

METHODS

Published research on the burden, disability, management, and economic costs of schizophrenia in the People's Republic of China was examined in the context of the larger body of global research. Research written in English or Chinese and published before June 2012 was identified using PubMed, CNKI, and Wanfang Med database searches. The contribution of effective antipsychotic therapy in reducing the risk for relapse and hospitalization and improving patients' functioning is described.

RESULTS

Schizophrenia imposes a substantial burden on Chinese society, with indirect costs accounting for the majority of the total cost. Functional impairment is high, leading to lost wages and work impairment. In the People's Republic of China, schizophrenia is the most common diagnosis among hospitalized psychiatric patients. Ongoing changes in the Chinese health care system may reduce some barriers to effective relapse prevention in schizophrenia and potentially reduce hospitalizations. The use of antipsychotics for acute episodes and maintenance treatment has been shown to decrease symptom severity and reduce the risk for relapse and hospitalization. However, discontinuing antipsychotic medication appears common and is a strong predictor of relapse. Cost-effectiveness research in the People's Republic of China is needed to examine the potential gains from improved outpatient antipsychotic treatment.

CONCLUSION

Schizophrenia is a very costly mental illness in terms of personal, economic, and societal burden, both in the People's Republic of China and globally. When treated effectively, patients tend to persist longer with antipsychotic treatment, have fewer costly relapses, and have improved functioning. Further research examining the long-term effects of reducing barriers to effective treatments on the societal burden of schizophrenia in the People's Republic of China is needed.

Schizophrenia: a neurodevelopmental disorder--integrative genomic hypothesis and therapeutic implications from a transgenic mouse model

Schizophrenia is a neurodevelopmental disorder featuring complex aberrations in the structure, wiring, and chemistry of multiple neuronal systems. The abnormal developmental trajectory of the brain appears to be established during gestation, long before clinical symptoms of the disease appear in early adult life. Many genes are associated with schizophrenia, however, altered expression of no one gene has been shown to be present in a majority of schizophrenia patients. How does altered expression of such a variety of genes lead to the complex set of abnormalities observed in the schizophrenic brain? We hypothesize that the protein products of these genes converge on common neurodevelopmental pathways that affect the development of multiple neural circuits and neurotransmitter systems. One such neurodevelopmental pathway is Integrative Nuclear FGFR1 Signaling (INFS). INFS integrates diverse neurogenic signals that direct the postmitotic development of embryonic stem cells, neural progenitors and immature neurons, by direct gene reprogramming. Additionally, FGFR1 and its partner proteins link multiple upstream pathways in which schizophrenia-linked genes are known to function and interact directly with those genes. A th-fgfr1(tk-) transgenic mouse with impaired FGF receptor signaling establishes a number of important characteristics that mimic human schizophrenia - a neurodevelopmental origin, anatomical abnormalities at birth, a delayed onset of behavioral symptoms, deficits across multiple domains of the disorder and symptom improvement with typical and atypical antipsychotics, 5-HT antagonists, and nicotinic receptor agonists. Our research suggests that altered FGF receptor signaling plays a central role in the developmental abnormalities underlying schizophrenia and that nicotinic agonists are an effective class of compounds for the treatment of schizophrenia.