Mapping genomic loci implicates genes and synaptic biology in schizophrenia

Schizophrenia has a heritability of 60-80%1, much of which is attributable to common risk alleles. Here, in a two-stage genome-wide association study of up to 76,755 individuals with schizophrenia and 243,649 control individuals, we report common variant associations at 287 distinct genomic loci. Associations were concentrated in genes that are expressed in excitatory and inhibitory neurons of the central nervous system, but not in other tissues or cell types. Using fine-mapping and functional genomic data, we identify 120 genes (106 protein-coding) that are likely to underpin associations at some of these loci, including 16 genes with credible causal non-synonymous or untranslated region variation. We also implicate fundamental processes related to neuronal function, including synaptic organization, differentiation and transmission. Fine-mapped candidates were enriched for genes associated with rare disruptive coding variants in people with schizophrenia, including the glutamate receptor subunit GRIN2A and transcription factor SP4, and were also enriched for genes implicated by such variants in neurodevelopmental disorders. We identify biological processes relevant to schizophrenia pathophysiology; show convergence of common and rare variant associations in schizophrenia and neurodevelopmental disorders; and provide a resource of prioritized genes and variants to advance mechanistic studies.

Psychiatric comorbidities and schizophrenia

Psychiatric comorbidities are common among patients with schizophrenia. Substance abuse comorbidity predominates. Anxiety and depressive symptoms are also very common throughout the course of illness, with an estimated prevalence of 15% for panic disorder, 29% for posttraumatic stress disorder, and 23% for obsessive-compulsive disorder. It is estimated that comorbid depression occurs in 50% of patients, and perhaps (conservatively) 47% of patients also have a lifetime diagnosis of comorbid substance abuse. This article chronicles these associations, examining whether these comorbidities are "more than chance" and might represent (distinct) phenotypes of schizophrenia. Among the anxiety disorders, the evidence at present is most abundant for an association with obsessive-compulsive disorder. Additional studies in newly diagnosed antipsychotic-naive patients and their first-degree relatives and searches for genetic and environmental risk factors are needed to replicate preliminary findings and further investigate these associations.

Rare coding variants in ten genes confer substantial risk for schizophrenia

Rare coding variation has historically provided the most direct connections between gene function and disease pathogenesis. By meta-analysing the whole exomes of 24,248 schizophrenia cases and 97,322 controls, we implicate ultra-rare coding variants (URVs) in 10 genes as conferring substantial risk for schizophrenia (odds ratios of 3-50, P < 2.14 × 10-6) and 32 genes at a false discovery rate of <5%. These genes have the greatest expression in central nervous system neurons and have diverse molecular functions that include the formation, structure and function of the synapse. The associations of the NMDA (N-methyl-D-aspartate) receptor subunit GRIN2A and AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid) receptor subunit GRIA3 provide support for dysfunction of the glutamatergic system as a mechanistic hypothesis in the pathogenesis of schizophrenia. We observe an overlap of rare variant risk among schizophrenia, autism spectrum disorders1, epilepsy and severe neurodevelopmental disorders2, although different mutation types are implicated in some shared genes. Most genes described here, however, are not implicated in neurodevelopment. We demonstrate that genes prioritized from common variant analyses of schizophrenia are enriched in rare variant risk3, suggesting that common and rare genetic risk factors converge at least partially on the same underlying pathogenic biological processes. Even after excluding significantly associated genes, schizophrenia cases still carry a substantial excess of URVs, which indicates that more risk genes await discovery using this approach.

Meta-analysis of oxidative stress in schizophrenia

BACKGROUND

Schizophrenia is associated with impaired antioxidant defense, including abnormal serum, plasma, and red blood cell (RBC) oxidative stress parameters. We performed a meta-analysis of these associations, considering the effect of clinical status and antipsychotic treatment after an acute exacerbation of psychosis.

METHODS

We identified articles by searching PubMed, PsychInfo, and Institute for Scientific Information, and the reference lists of identified studies.

RESULTS

Forty-four studies met the inclusion criteria. Total antioxidant status seemed to be a state marker, because levels were significantly decreased in cross-sectional studies of serum and plasma in first-episode psychosis (FEP) and significantly increased in longitudinal studies of antipsychotic treatment for acute exacerbations of psychosis (p < .01 for each). The RBC catalase and plasma nitrite seemed to be state-related markers, because levels in cross-sectional studies were significantly decreased in FEP (p < .01) and significantly increased in stable outpatients (p = .01). In contrast, RBC superoxide dismutase seemed to be a trait marker for schizophrenia, because levels in cross-sectional studies were significantly decreased in acutely relapsed inpatients, FEP, and stable outpatients (p < .01 for each).

CONCLUSIONS

Oxidative stress abnormalities in FEP suggest an effect that might be independent of antipsychotic medications. Although some parameters (total antioxidant status, RBC catalase, and plasma nitrite) might be state markers for acute exacerbations of psychosis, others (RBC superoxide dismutase) might be trait markers; however, more longitudinal studies are needed. Our findings suggest that oxidative stress might serve as a potential biomarker in the etiopathophysiology and clinical course of schizophrenia.

Identification of vascular structures as a major source of signal contrast in high resolution 2D and 3D functional activation imaging of the motor cortex at 1.5T: preliminary results

We have measured the T2* signal response associated with cortical activation due to finger motion at 1.5 Tesla. Both thin slice 2D and 3D images show signal intensity changes which vary from 2% to 32% depending on volunteer, echo time, slice thickness, and in-plane resolution. The largest signal change occurred for the thinnest slices and highest resolution (2 mm3). This is consistent with reducing partial volume effects and a simple difference in phase between the intravascular signal and surrounding parenchyma. No inflow enhancement was seen on the 2D or 3D scans, confirming the nature of the signal difference for this approach was due to local field inhomogeneity effects. Using 3D imaging, multiple effects can be seen simultaneously. With a 3D MRA method, it was possible to locate the vessel that was the source of the T2* behavior; it was in each case a vein on the surface of the cortical parenchyma.

Improvement in cognitive functions and psychiatric symptoms in treatment-refractory schizophrenic patients receiving clozapine

Cognitive functions and psychopathology were assessed in 36 treatment-refractory schizophrenic patients before initiation of clozapine, and at 6 weeks and 6 months, thereafter. Before treatment, cognitive impairment was found in each measure of memory, attention, and executive function as compared with 26 normal controls. After both 6 weeks and 6 months of treatment, significant improvement occurred in the Controlled Oral Word Association Test, a measure of retrieval from reference memory. Improvement was also noted at 6 months in the Category Instance Generation Test, another measure of retrieval from reference memory, and in some, but not all, tests of executive function, attention, and recall memory. Clozapine treatment also resulted in significant improvement in Brief Psychiatric Rating Scale (BPRS) Total and Positive symptom scores at both 6-week and 6-month assessment points. There was some evidence for a relationship between improvement in psychopathology and cognitive function. The improvement in cognitive function during clozapine treatment could have consequences for capacity to work and social function.

Neutrophil gelatinase-associated lipocalin in normal and neoplastic human tissues. Cell type-specific pattern of expression

Neutrophil gelatinase-associated lipocalin (NGAL) has recently been identified in myeloperoxidase-negative neutrophil granules. Members of the lipocalin family are thought to bind and transport small lipophilic molecules such as retinoids and roles in cell regulation have been proposed. Recently, NGAL has also been demonstrated in the colonic mucosa in certain pathologic conditions. The aim of this study was to examine the distribution of NGAL in normal and neoplastic tissues by immunohistochemistry. Interestingly, NGAL was found in a variety of normal and pathological human tissues. A cell type-specific pattern of expression was seen in bronchus, stomach, small intestine, pancreas, kidney, prostate gland, and thymus. The comparative analysis of the putative rat homologue neu-related lipocalin showed a very similar pattern of expression with the exception of pancreas and kidney. Neoplastic human tissues showed a very heterogeneous expression of NGAL protein. High NGAL levels were found in adenocarcinomas of lung, colon and pancreas. In contrast, renal cell carcinomas of various subtypes and prostate cancers contained low NGAL levels. Lymphomas and thymic tumours were negative for NGAL immuno-labeling. Knowledge about the location of NGAL in normal cells and in disease states provides the first clues towards understanding its biological function.

Clinical characteristics with inflammation profiling of long COVID and association with 1-year recovery following hospitalisation in the UK: a prospective observational study

BACKGROUND

No effective pharmacological or non-pharmacological interventions exist for patients with long COVID. We aimed to describe recovery 1 year after hospital discharge for COVID-19, identify factors associated with patient-perceived recovery, and identify potential therapeutic targets by describing the underlying inflammatory profiles of the previously described recovery clusters at 5 months after hospital discharge.

METHODS

The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a prospective, longitudinal cohort study recruiting adults (aged ≥18 years) discharged from hospital with COVID-19 across the UK. Recovery was assessed using patient-reported outcome measures, physical performance, and organ function at 5 months and 1 year after hospital discharge, and stratified by both patient-perceived recovery and recovery cluster. Hierarchical logistic regression modelling was performed for patient-perceived recovery at 1 year. Cluster analysis was done using the clustering large applications k-medoids approach using clinical outcomes at 5 months. Inflammatory protein profiling was analysed from plasma at the 5-month visit. This study is registered on the ISRCTN Registry, ISRCTN10980107, and recruitment is ongoing.

FINDINGS

2320 participants discharged from hospital between March 7, 2020, and April 18, 2021, were assessed at 5 months after discharge and 807 (32·7%) participants completed both the 5-month and 1-year visits. 279 (35·6%) of these 807 patients were women and 505 (64·4%) were men, with a mean age of 58·7 (SD 12·5) years, and 224 (27·8%) had received invasive mechanical ventilation (WHO class 7-9). The proportion of patients reporting full recovery was unchanged between 5 months (501 [25·5%] of 1965) and 1 year (232 [28·9%] of 804). Factors associated with being less likely to report full recovery at 1 year were female sex (odds ratio 0·68 [95% CI 0·46-0·99]), obesity (0·50 [0·34-0·74]) and invasive mechanical ventilation (0·42 [0·23-0·76]). Cluster analysis (n=1636) corroborated the previously reported four clusters: very severe, severe, moderate with cognitive impairment, and mild, relating to the severity of physical health, mental health, and cognitive impairment at 5 months. We found increased inflammatory mediators of tissue damage and repair in both the very severe and the moderate with cognitive impairment clusters compared with the mild cluster, including IL-6 concentration, which was increased in both comparisons (n=626 participants). We found a substantial deficit in median EQ-5D-5L utility index from before COVID-19 (retrospective assessment; 0·88 [IQR 0·74-1·00]), at 5 months (0·74 [0·64-0·88]) to 1 year (0·75 [0·62-0·88]), with minimal improvements across all outcome measures at 1 year after discharge in the whole cohort and within each of the four clusters.

INTERPRETATION

The sequelae of a hospital admission with COVID-19 were substantial 1 year after discharge across a range of health domains, with the minority in our cohort feeling fully recovered. Patient-perceived health-related quality of life was reduced at 1 year compared with before hospital admission. Systematic inflammation and obesity are potential treatable traits that warrant further investigation in clinical trials.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Ultra-Rare Genetic Variation in the Epilepsies: A Whole-Exome Sequencing Study of 17,606 Individuals

Sequencing-based studies have identified novel risk genes associated with severe epilepsies and revealed an excess of rare deleterious variation in less-severe forms of epilepsy. To identify the shared and distinct ultra-rare genetic risk factors for different types of epilepsies, we performed a whole-exome sequencing (WES) analysis of 9,170 epilepsy-affected individuals and 8,436 controls of European ancestry. We focused on three phenotypic groups: severe developmental and epileptic encephalopathies (DEEs), genetic generalized epilepsy (GGE), and non-acquired focal epilepsy (NAFE). We observed that compared to controls, individuals with any type of epilepsy carried an excess of ultra-rare, deleterious variants in constrained genes and in genes previously associated with epilepsy; we saw the strongest enrichment in individuals with DEEs and the least strong in individuals with NAFE. Moreover, we found that inhibitory GABA_A receptor genes were enriched for missense variants across all three classes of epilepsy, whereas no enrichment was seen in excitatory receptor genes. The larger gene groups for the GABAergic pathway or cation channels also showed a significant mutational burden in DEEs and GGE. Although no single gene surpassed exome-wide significance among individuals with GGE or NAFE, highly constrained genes and genes encoding ion channels were among the lead associations; such genes included CACNA1G, EEF1A2, and GABRG2 for GGE and LGI1, TRIM3, and GABRG2 for NAFE. Our study, the largest epilepsy WES study to date, confirms a convergence in the genetics of severe and less-severe epilepsies associated with ultra-rare coding variation, and it highlights a ubiquitous role for GABAergic inhibition in epilepsy etiology.

Enteral versus parenteral nutrition: a pragmatic study

Controversy persists as to the optimal means of providing adjuvant nutritional support. The aim of this study was to compare enteral nutrition (EN) and parenteral nutrition (TPN) in terms of adequacy of nutritional intake, septic and nonseptic morbidity, and mortality. This was a prospective pragmatic study, whereby the route of delivery of nutritional support was determined by the attending clinician's assessment of gastrointestinal function. Patients considered to have inadequate gastrointestinal function were given TPN (group 1), while those deemed to have a functioning gastrointestinal tract received EN (group 2). Patients in whom there was reasonable doubt as to the adequacy of intestinal function were randomized to receive either TPN (group 3) or EN (group 4). The trial setting was a large district general hospital with a dedicated nutrition team. A total of 562 patients were included in the study (331 males; median age 67 y). Gastrointestinal function on entry into the study was considered inadequate in 267 patients who were given TPN (group 1) and adequate in 231 whom received EN (group 2). There was clinical uncertainty about the adequacy of gut function in 64 patients (11.4%) who were randomized to receive either TPN (group 3, 32 patients) or EN (group 4, 32 patients). The incidence of inadequate nutritional intake was significantly higher in group 4 compared with group 3 (78.1% versus 25%, P < 0.001). Complications related to the delivery system and other feed-related morbidity were significantly more frequent in both EN groups compared with the respective TPN groups. EN was associated with a higher overall mortality in both nonrandomized and randomized patients. There were no significant differences observed in the incidences of septic morbidity between patients receiving TPN and those given EN. EN is associated with a higher incidence of inadequate nutritional intake, complications related to the delivery system, and other feed-related morbidity than TPN. There is no evidence from this study to support a difference between the two modalities in terms of septic morbidity. Patients in whom there is reasonable doubt as to the adequacy of gastrointestinal function should be fed by the parenteral route.

The Texas Medication Algorithm Project antipsychotic algorithm for schizophrenia: 2006 update

BACKGROUND

A panel of academic psychiatrists and pharmacists, clinicians from the Texas public mental health system, advocates, and consumers met in June 2006 in Dallas, Tex., to review recent evidence in the pharmacologic treatment of schizophrenia. The goal of the consensus conference was to update and revise the Texas Medication Algorithm Project (TMAP) algorithm for schizophrenia used in the Texas Implementation of Medication Algorithms, a statewide quality assurance program for treatment of major psychiatric illness.

METHOD

Four questions were identified via premeeting teleconferences. (1) Should antipsychotic treatment of first-episode schizophrenia be different from that of multiepisode schizophrenia? (2) In which algorithm stages should first-generation antipsychotics (FGAs) be an option? (3) How many antipsychotic trials should precede a clozapine trial? (4) What is the status of augmentation strategies for clozapine? Subgroups reviewed the evidence in each area and presented their findings at the conference.

RESULTS

The algorithm was updated to incorporate the following recommendations. (1) Persons with first-episode schizophrenia typically require lower antipsychotic doses and are more sensitive to side effects such as weight gain and extrapyramidal symptoms (group consensus). Second-generation antipsychotics (SGAs) are preferred for treatment of first-episode schizophrenia (majority opinion). (2) FGAs should be included in algorithm stages after first episode that include SGAs other than clozapine as options (group consensus). (3) The recommended number of trials of other antipsychotics that should precede a clozapine trial is 2, but earlier use of clozapine should be considered in the presence of persistent problems such as suicidality, comorbid violence, and substance abuse (group consensus). (4) Augmentation is reasonable for persons with inadequate response to clozapine, but published results on augmenting agents have not identified replicable positive results (group consensus).

CONCLUSIONS

These recommendations are meant to provide a framework for clinical decision making, not to replace clinical judgment. As with any algorithm, treatment practices will evolve beyond the recommendations of this consensus conference as new evidence and additional medications become available.

Meta-analysis of lymphocytes in schizophrenia: clinical status and antipsychotic effects

BACKGROUND

Schizophrenia is associated with immune system dysfunction, including abnormal blood immune cell parameters. We performed a meta-analysis of these associations, considering the effect of clinical status and antipsychotic treatment following an acute exacerbation of psychosis.

METHODS

We identified articles by searching PubMed, PsycINFO, and Thomson Reuters (formerly ISI) Web of Knowledge and the reference lists of identified studies.

RESULTS

Sixteen studies of blood lymphocytes met the inclusion criteria. There was insufficient data for a meta-analysis of the mononuclear phagocytic system. In cross-sectional studies, there was a significant increase in the CD4% and CD56% in acutely relapsed inpatients. Absolute levels of total lymphocytes, CD3, and CD4, and the CD4/CD8 ratio were significantly increased, and the CD3% was significantly decreased in drug-native first-episode psychosis. In longitudinal studies, the CD4/CD8 ratio appeared to be state-related markers, as it decreased following antipsychotic treatment for acute exacerbations of psychosis. Absolute CD56 levels appeared to be a trait marker, as levels significantly increased following antipsychotic treatment for relapse.

CONCLUSIONS

Blood lymphocyte abnormalities in drug-naïve first-episode psychosis suggest an effect that may be independent of antipsychotic medications. While some parameters (CD4/CD8) may be state markers for acute exacerbations of psychosis, others (CD56) may be trait markers; however, more longitudinal studies are needed. Although these findings could provide the basis for future hypothesis testing, a relatively small number of studies and subjects, lack of correlative data with clinical features, and inadequate consideration of potential confounding factors limit the results.

Correction: An International Adult Guideline for Making Clozapine Titration Safer by Using Six Ancestry-Based Personalized Dosing Titrations, CRP, and Clozapine Levels

This international guideline proposes improving clozapine package inserts worldwide by using ancestry-based dosing and titration. Adverse drug reaction (ADR) databases suggest that clozapine is the third most toxic drug in the United States (US), and it produces four times higher worldwide pneumonia mortality than that by agranulocytosis or myocarditis. For trough steady-state clozapine serum concentrations, the therapeutic reference range is narrow, from 350 to 600 ng/mL with the potential for toxicity and ADRs as concentrations increase. Clozapine is mainly metabolized by CYP1A2 (female non-smokers, the lowest dose; male smokers, the highest dose). Poor metabolizer status through phenotypic conversion is associated with co-prescription of inhibitors (including oral contraceptives and valproate), obesity, or inflammation with C-reactive protein (CRP) elevations. The Asian population (Pakistan to Japan) or the Americas’ original inhabitants have lower CYP1A2 activity and require lower clozapine doses to reach concentrations of 350 ng/mL. In the US, daily doses of 300–600 mg/day are recommended. Slow personalized titration may prevent early ADRs (including syncope, myocarditis, and pneumonia). This guideline defines six personalized titration schedules for inpatients: 1) ancestry from Asia or the original people from the Americas with lower metabolism (obesity or valproate) needing minimum therapeutic dosages of 75–150 mg/day, 2) ancestry from Asia or the original people from the Americas with average metabolism needing 175–300 mg/day, 3) European/Western Asian ancestry with lower metabolism (obesity or valproate) needing 100–200 mg/day, 4) European/Western Asian ancestry with average metabolism needing 250–400 mg/day, 5) in the US with ancestries other than from Asia or the original people from the Americas with lower clozapine metabolism (obesity or valproate) needing 150–300 mg/day, and 6) in the US with ancestries other than from Asia or the original people from the Americas with average clozapine metabolism needing 300–600 mg/day. Baseline and weekly CRP monitoring for at least four weeks is required to identify any inflammation, including inflammation secondary to clozapine rapid titration.

Evidence for genetic heterogeneity between clinical subtypes of bipolar disorder

We performed a genome-wide association study of 6447 bipolar disorder (BD) cases and 12 639 controls from the International Cohort Collection for Bipolar Disorder (ICCBD). Meta-analysis was performed with prior results from the Psychiatric Genomics Consortium Bipolar Disorder Working Group for a combined sample of 13 902 cases and 19 279 controls. We identified eight genome-wide significant, associated regions, including a novel associated region on chromosome 10 (rs10884920; P=3.28 × 10-8) that includes the brain-enriched cytoskeleton protein adducin 3 (ADD3), a non-coding RNA, and a neuropeptide-specific aminopeptidase P (XPNPEP1). Our large sample size allowed us to test the heritability and genetic correlation of BD subtypes and investigate their genetic overlap with schizophrenia and major depressive disorder. We found a significant difference in heritability of the two most common forms of BD (BD I SNP-h2=0.35; BD II SNP-h2=0.25; P=0.02). The genetic correlation between BD I and BD II was 0.78, whereas the genetic correlation was 0.97 when BD cohorts containing both types were compared. In addition, we demonstrated a significantly greater load of polygenic risk alleles for schizophrenia and BD in patients with BD I compared with patients with BD II, and a greater load of schizophrenia risk alleles in patients with the bipolar type of schizoaffective disorder compared with patients with either BD I or BD II. These results point to a partial difference in the genetic architecture of BD subtypes as currently defined.

The Texas Medication Algorithm Project antipsychotic algorithm for schizophrenia: 2003 update

BACKGROUND

The Texas Medication Algorithm Project (TMAP) has been a public-academic collaboration in which guidelines for medication treatment of schizophrenia, bipolar disorder, and major depressive disorder were used in selected public outpatient clinics in Texas. Subsequently, these algorithms were implemented throughout Texas and are being used in other states. Guidelines require updating when significant new evidence emerges; the antipsychotic algorithm for schizophrenia was last updated in 1999. This article reports the recommendations developed in 2002 and 2003 by a group of experts, clinicians, and administrators.

METHOD

A conference in January 2002 began the update process. Before the conference, experts in the pharmacologic treatment of schizophrenia, clinicians, and administrators reviewed literature topics and prepared presentations. Topics included ziprasidone's inclusion in the algorithm, the number of antipsychotics tried before clozapine, and the role of first generation antipsychotics. Data were rated according to Agency for Healthcare Research and Quality criteria. After discussing the presentations, conference attendees arrived at consensus recommendations. Consideration of aripiprazole's inclusion was subsequently handled by electronic communications.

RESULTS

The antipsychotic algorithm for schizophrenia was updated to include ziprasidone and aripiprazole among the first-line agents. Relative to the prior algorithm, the number of stages before clozapine was reduced. First generation antipsychotics were included but not as first-line choices. For patients refusing or not responding to clozapine and clozapine augmentation, preference was given to trying monotherapy with another antipsychotic before resorting to antipsychotic combinations.

CONCLUSION

Consensus on algorithm revisions was achieved, but only further well-controlled research will answer many key questions about sequence and type of medication treatments of schizophrenia.

Novel antipsychotics and the neuroleptic malignant syndrome: a review and critique

OBJECTIVE

The authors' goal was to analyze reported cases of neuroleptic malignant syndrome in patients given clozapine and risperidone.

METHOD

They assessed 19 cases of clozapine-induced neuroleptic malignant syndrome and 13 cases of risperidone-induced neuroleptic malignant syndrome against three criteria sets and against extent of exclusionary workup and then designated them as high or low probability of being neuroleptic malignant syndrome.

RESULTS

Nine of the 19 cases of clozapine-related neuroleptic malignant syndrome and eight of the 13 cases of risperidone-related neuroleptic malignant syndrome were designated as having high probability of being neuroleptic malignant syndrome. The remainder were designated as having low probability because presentations were not linked to treatment or failed to meet criteria for the syndrome.

CONCLUSIONS

Neuroleptic malignant syndrome can occur in patients given atypical antipsychotics and resembles "classical" neuroleptic malignant syndrome. However, side effect profiles overlap considerably with neuroleptic malignant syndrome criteria, and atypical antipsychotics may cause neurotoxicities unrelated to (but misattributed as) neuroleptic malignant syndrome. Insufficient evidence exists for "atypical" neuroleptic malignant syndrome with novel antipsychotics.

Red blood cell membrane essential fatty acid metabolism in early psychotic patients following antipsychotic drug treatment

A role of indices of oxidative stress, oxidative injury, and abnormal membrane phospholipid, specifically the phospholipid essential polyunsaturated fatty acids (EPUFAs) metabolism has been suggested based on studies in separate groups of patients with or without medication. The current study investigated the relationship between these biochemical measures in first-episode psychotic patients (N=16) at baseline and after 6 months of antipsychotic treatment (N=5 each with risperidone and olanzapine) and compared them to matched normal subjects. The indices of oxidative stress included: antioxidant enzymes; superoxide dismutase, glutathione peroxidase and catalase; and the oxidative injury as the levels of plasma lipid peroxides. The key membrane EPUFA's been; linolenic acid, arachidonic acid, nervonic acid, docosapentaenoic acid and docosahexaenoic acid. Furthermore, the changes in these biochemical measures were correlated with clinical symptomatology. Data indicated that, at baseline, reduced levels of antioxidant enzymes were associated with increased plasma lipid peroxides and reduced membrane EPUFAs, particularly omega-3 fatty acids. Furthermore, these biochemical measures normalized after 6 months of antipsychotic treatment. Parallel-improved psychopathology indicated that membrane EPUFA status might be partly affected by oxidative damage, which together may contribute to the pathophysiology and thereby, psychopathology of schizophrenia. These data also support the augmentation of antipsychotic treatment by supplementation with a combination of antioxidants and omega-3 fatty acids.

Treatment-Resistant Schizophrenia

Although treatment-resistant schizophrenia (TRS) was described 50 years ago and has a gold standard treatment with clozapine based on well-defined criteria, there is still a matter of great interest and controversy. In terms of the underlying mechanisms of the development of TRS, progress has been made for the elucidation of the neurochemical mechanisms. Structural neuroimaging studies have shown that patients with TRS have significant reduction of the prefrontal cortex volume when compared with non- TRS. This article updates and enhances our previous review with new evidence mainly derived from new studies, clinical trials, systematic reviews, and meta-analyses.

Medication nonadherence and treatment outcome in patients with schizophrenia or schizoaffective disorder with suboptimal prior response

OBJECTIVE

To examine the impact of medication nonadherence on treatment outcome in schizophrenia and potential risk factors for nonadherence.

METHOD

A post hoc analysis of a randomized, double-blind, 8-week, fixed-dose study comparing olanzapine 10, 20, and 40 mg/day for patients with schizophrenia or schizoaffective disorder (DSM-IV criteria) with suboptimal response to current treatment (N = 599) was conducted between September 12, 2003, and November 3, 2005, at 55 study centers in the United States. Nonadherence was defined as not taking medication as prescribed based on daily pill counts. Because there was no significant difference in nonadherence between dose groups, effects of nonadherence on efficacy and safety outcomes were examined using all 3 groups combined. Baseline demographics and symptom severity were investigated as potential risk factors for nonadherence.

RESULTS

During the 8-week study, 34.5% of patients were nonadherent at least once. Nonadherent patients had significantly less improvement compared to adherent patients as measured by change in Positive and Negative Syndrome Scale total score (-22.57 vs. -26.84, p = .002). Longer duration of nonadherence was associated with reduced likelihood of treatment response (odds ratio = 0.94, 95% CI = 0.90 to 0.99, p = .008). The early treatment discontinuation rate was higher in nonadherent compared to adherent patients (40.8% vs. 24.5%, p < .001). Adherent and nonadherent patients had comparable outcomes in most safety measures, except for weight change, for which adherent patients had greater weight gain than nonadherent patients (2.63 kg vs. 1.96 kg, p = .02). Greater depression severity at baseline (p = .01) and greater hostility level during the study were significant risk factors for nonadherence (p = .02).

CONCLUSIONS

Medication nonadherence had a significantly negative impact on treatment response, highlighting the importance of adherence to achieve satisfactory treatment outcome. Findings may also help clinicians identify patients at risk for nonadherence and utilize interventions to improve adherence.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00100776.

Lack of insight in schizophrenia: impact on treatment adherence

People with schizophrenia commonly lack insight, that is, they are unaware of their illness and the consequences thereof. One of the most important consequences of lack of insight is a failure to recognise the need for treatment, leading to treatment nonadherence. With several scales that now enable objective measurement of insight, it is possible to examine correlates of insight change, including course of illness and treatment adherence. Specific interventions, both pharmacological and psychotherapeutic, have been developed to enhance illness insight and treatment adherence. The extent to which second-generation antipsychotic medications, including a recently released long-acting formulation, improve insight and/or enhance treatment adherence remains to be determined.

Clozapine-induced weight gain associated with the 5HT2C receptor -759C/T polymorphism

Weight gain has been documented as a significant adverse effect associated with many of the atypical antipsychotic medications. Several recent reports have linked a -759C/T polymorphism of the 5HT2C receptor gene and obesity as well as chlorpromazine, risperidone, and clozapine induced to weight gain. This aim was to determine the association between changes in body mass index (BMI) during clozapine treatment and the -759C/T polymorphism of the 5HT2C receptor gene. This study included 41 patients with treatment-refractory schizophrenia (DSM-IV) who were followed prospectively during treatment with clozapine. Weight and height measurements were obtained prior to starting clozapine and after 6-months of treatment. Genomic DNA was isolated from a whole blood sample and analyzed for the -759C/T polymorphism of the 5HT2C receptor gene. A chi(2) analysis comparing whether or not the subjects carried a -759T allele in subjects grouped as having an increase of more or less than 7% of their baseline BMI during treatment with clozapine found that the presence of the -759T allele was significantly higher in subjects with less than or equal to a 7% increase in baseline BMI compared to those with a greater than 7% increase in BMI. A multiple linear regression analysis showed that both baseline BMI and the presence or absence of the -759T allele had significant effects on 6-month BMI. The T allele may have a protective function in preventing significant weight gain from clozapine. Subjects without the -759T variant allele were at a greater risk for weight gain from clozapine over 6-months compared to those with the -759T allele.

Negative symptoms of schizophrenia: a problem that will not go away

OBJECTIVE

Negative symptoms of schizophrenia are a common, enduring, and debilitating component of the psychopathology of schizophrenia. Although efforts thus far to elucidate a distinct schizophrenia subtype based upon negative symptoms have yielded mixed results, there are nevertheless neurobiological correlates of the negative symptom typology.

METHOD

A review of nosology, typology, and assessment tools for determining core negative symptoms in schizophrenia.

RESULTS

Negative symptoms can be difficult to evaluate objectively. Current rating scales 'capture' key domains of negative symptoms, in spite of considerable overlap between these domains. However, each objective assessment trades off methodological rigor and detail against brevity of assessment and ease of use.

CONCLUSION

The description of new methods for measuring these devastating symptoms, coupled with the ongoing development of novel antipsychotics and agents that augment antipsychotics have fuelled renewed interest in the evaluation of negative symptoms and optimism that better treatments for negative symptoms can be found.

Neurotrophins and schizophrenia

Neurotrophins have established roles in neuronal development, synaptogenesis, and response to stress/anxious stimuli. Moreover, these agents are neuromodulators of monoaminergic, GABAergic, and cholinergic systems. Amidst a growing appreciation of the developmental neurobiology of schizophrenia--as well as the propensity for progressive brain changes--there is emergent information on abnormalities in the expression of neurotrophins in schizophrenia. This article reviews the literature on neurotrophins and schizophrenia. A schema for understanding the neurobiology of relapse in schizophrenia is offered.

2D and 3D high resolution gradient echo functional imaging of the brain: venous contributions to signal in motor cortex studies

Recent emphasis on high resolution gradient echo studies in functional imaging has led to the conclusion that there are likely three domains of response to the blood circulation in the brain when considering field inhomogeneity effects of the venous blood pre- and during activation. The first is a coherent effect due to large or macroscopic vessels on the order of the size of the voxel (ca 200-500 microns in most studies). These can lead to very large signal changes (up to 100%). The second is at the venule level (ca 50-200 microns) and is associated with smaller parenchymal changes (usually ca 10% or less). The third is at the capillary level and is associated with much smaller signal changes at 1.5 T and even up to 4 T. The actual signal changes depend on field strength and sequence design. In this paper, we present our experience in detecting the first two domains with 2D and 3D gradient echo imaging at 1.5 T. We find that high resolution enables visualization of the larger small veins in motor cortex studies and that, on occasion, it is possible to see the venule effects as well. We suggest a simple model to explain the large signal changes based on susceptibility changes and partial volume effects. Comparisons of the functional imaging data to this model and to MR angiographic studies are also shown as evidence of the venous sources of the susceptibility changes.