Long-term follow-up of clozapine prescribing

OBJECTIVE

Clozapine is uniquely effective for treatment-resistant schizophrenia, and so treatment continuation is essential. We aimed to identify factors associated with an increased likelihood of clozapine discontinuation in a cohort of patients in South East London.

METHODS

We gathered demographic and treatment information such as duration of illness and antipsychotic treatment history. t-tests, chi-square tests and binary logistic regression were used to compare patients who continued and discontinued clozapine during the study and to identify predictor variables for discontinuation.

RESULTS

Out of the study population of 133 patients, 48 discontinued clozapine at least once during the study period. The majority of these (75%) stopped treatment within the first 4 years of clozapine therapy. Age, ethnicity, diagnosis and antipsychotic treatment history were not predictive of the risk of clozapine discontinuation. However, male patients were more likely to stop taking clozapine (χ² = 6.81, p = 0.009). The odds of discontinuing clozapine were 2.15 times higher for male patients. The most common reason for discontinuation was patient refusal of treatment.

CONCLUSION

We found that patients who discontinue clozapine are more likely to be male, but no other demographic variable was found to predict treatment cessation. Discontinuation usually occurred due to patient refusal of treatment.

Real-time fMRI neurofeedback to down-regulate superior temporal gyrus activity in patients with schizophrenia and auditory hallucinations: a proof-of-concept study

Neurocognitive models and previous neuroimaging work posit that auditory verbal hallucinations (AVH) arise due to increased activity in speech-sensitive regions of the left posterior superior temporal gyrus (STG). Here, we examined if patients with schizophrenia (SCZ) and AVH could be trained to down-regulate STG activity using real-time functional magnetic resonance imaging neurofeedback (rtfMRI-NF). We also examined the effects of rtfMRI-NF training on functional connectivity between the STG and other speech and language regions. Twelve patients with SCZ and treatment-refractory AVH were recruited to participate in the study and were trained to down-regulate STG activity using rtfMRI-NF, over four MRI scanner visits during a 2-week training period. STG activity and functional connectivity were compared pre- and post-training. Patients successfully learnt to down-regulate activity in their left STG over the rtfMRI-NF training. Post- training, patients showed increased functional connectivity between the left STG, the left inferior prefrontal gyrus (IFG) and the inferior parietal gyrus. The post-training increase in functional connectivity between the left STG and IFG was associated with a reduction in AVH symptoms over the training period. The speech-sensitive region of the left STG is a suitable target region for rtfMRI-NF in patients with SCZ and treatment-refractory AVH. Successful down-regulation of left STG activity can increase functional connectivity between speech motor and perception regions. These findings suggest that patients with AVH have the ability to alter activity and connectivity in speech and language regions, and raise the possibility that rtfMRI-NF training could present a novel therapeutic intervention in SCZ.

The value of novelty in schizophrenia

Influential models of schizophrenia suggest that patients experience incoming stimuli as excessively novel and motivating, with important consequences for hallucinatory experience and delusional belief. However, whether schizophrenia patients exhibit excessive novelty value and whether this interferes with adaptive behaviour has not yet been formally tested. Here, we employed a three-armed bandit task to investigate this hypothesis. Schizophrenia patients and healthy controls were first familiarised with a group of images and then asked to repeatedly choose between familiar and unfamiliar images associated with different monetary reward probabilities. By fitting a reinforcement-learning model we were able to estimate the values attributed to familiar and unfamiliar images when first presented in the context of the decision-making task. In line with our hypothesis, we found increased preference for newly introduced images (irrespective of whether these were familiar or unfamiliar) in patients compared to healthy controls and this to correlate with severity of hallucinatory experience. In addition, we found a correlation between value assigned to novel images and task performance, suggesting that excessive novelty value may interfere with optimal learning in patients, putatively through the disruption of the mechanisms regulating exploration versus exploitation. Our results suggest excessive novelty value in patients, whereby even previously seen stimuli acquire higher value as the result of their exposure in a novel context - a form of 'hyper novelty' which may explain why patients are often attracted by familiar stimuli experienced as new.

Everything you wanted to know about neuroimaging and psychiatry, but were afraid to ask

Recent years have seen a dramatic increase in the advances and applications of medical imaging techniques. Tools with familiar acronyms such as MRI, EEG/MEG and PET/SPECT have provided invaluable information not only about the brain structure and function associated with psychiatric disorders, but increasingly about the mechanisms underpinning these disorders. This evolving understanding of the specific pathophysiology of mental disorder paves the way for improvement in the diagnosis, treatment and prognosis of the disorders managed in everyday clinical practice. This article gives an overview of the main neuroimaging approaches, contemporary applications of this technology to psychiatric disorder and signposts to the exciting possibilities for the future.

Decreased value-sensitivity in schizophrenia

Pathophysiology in schizophrenia has been linked to aberrant incentive salience, namely the dysfunctional processing of value linked to abnormal dopaminergic activity. In line with this, recent studies showed impaired learning of value in schizophrenia. However, how value is used to guide behaviour independently from learning, as in risky choice, has rarely been examined in this disorder. We studied value-guided choice under risk in patients with schizophrenia and in controls using a task requiring a choice between a certain monetary reward, varying trial-by-trial, and a gamble offering an equal probability of getting double this certain amount or nothing. We observed that patients compared to controls exhibited reduced sensitivity to values, implying that their choices failed to flexibly adapt to the specific values on offer. Moreover, the degree of this value sensitivity inversely correlated with aberrant salience experience, suggesting that the inability to tune choice to value may be a key element of aberrant salience in the illness. Our results help clarify the cognitive mechanisms underlying improper attribution of value in schizophrenia and may thus inform cognitive interventions aimed at reinstating value sensitivity in patients.

When the drugs don't work: treatment-resistant schizophrenia, serotonin and serendipity

Treatment-resistant schizophrenia is a serious clinical problem. We adopt a systems-level approach positing a greater role for cognitive control mechanisms in the development of psychotic symptoms and illustrate the clinical application of this via a case report of treatment-resistant patients treated successfully with adjunct pro-cognitive serotonergic medication.

Are we failing clinical trials? A case for strong aggregate outcomes

Clinical trials in psychiatry inherit methods for design and statistical analysis from evidence-based medicine. However, trials in other clinical disciplines benefit from a more specific relationship between instruments that measure disease state (e.g. biomarkers, clinical signs), the underlying pathology and diagnosis such that primary outcomes can be readily defined. Trials in psychiatry use diagnosis (i.e. a categorical label for a syndrome) as a proxy for the underlying disorder, and outcomes are defined, for example, as a percentage change in a univariate total score on some clinical instrument. We label this approach to defining outcomes weak aggregation of disease state. Univariate measures are necessary, because statistical methodology is both tractable and well-developed for scalar outcomes, but we show that weak aggregate approaches do not capture disease state sufficiently, potentially leading to loss of information about response to intervention. We demonstrate how multivariate disease state can be captured using geometric concepts of spaces defined over routine clinical instruments, and show how clinically meaningful disease states (e.g. representing different profiles of symptoms, recovery or remission) can be defined as prototypes (geometric locations) in these spaces. Then, we show how to derive univariate (scalar) measures, which capture patient's relationships to these prototypes and argue these represent strong aggregates of disease state that may be a better basis for outcome measures. We demonstrate our proposal using a large publically available dataset. We conclude by discussing the impact of strong aggregates for analyses in traditional and novel trial designs.

White matter deficits in schizophrenia are global and don't progress with age

INTRODUCTION

Diffusion tensor imaging has revealed differences in all examined white matter tracts in schizophrenia, with a range of explanations for why this may be. The distribution and timing of differences may help explain their origin; however, results are usually dependent on the analytical method. We therefore sought to examine the extent of differences and their relationship with age using two different methods.

METHODS

A combined voxel-based whole-brain study and a tract-based spatial-statistics study of 104 patients with schizophrenia and 200 matched healthy controls, aged between 17 and 63 years.

RESULTS

Fractional anisotropy was reduced throughout the brain in both analyses. The relationship of fractional anisotropy with age differed between patients and controls, with controls showing the gentle fractional anisotropy decline widely noted but patients showing an essentially flat relationship: younger patients had lower fractional anisotropy than controls, but the difference disappeared with age. Mean diffusivity was widely increased in patients.

CONCLUSION

Reduction in fractional anisotropy and increase in mean diffusivity would be consistent with global disruption in myelination; the relationship with age would suggest this is present already at the onset of their illness, but does not progress.

Rapid-onset clozapine-induced loss of glycaemic control: case report

Clozapine has proved to be an effective antipsychotic for the treatment of refractory schizophrenia - characterised by the persistence of symptoms despite optimal treatment trials with at least two different antipsychotics at adequate dose and duration - but its use is hampered by adverse effects. The development of clozapine-induced diabetes is commonly considered to arise as part of a metabolic syndrome, associated with weight gain, and thus evolves slowly. We present the case of an individual with refractory schizophrenia and metformin-controlled diabetes who developed rapid-onset insulin-dependent hyperglycaemia immediately after starting clozapine. Given the refractory nature of his illness, the decision was made to continue clozapine and manage the diabetes. This case supports the existence of a more direct mechanism by which clozapine alters glycaemic control, aside from the more routine slow development of a metabolic syndrome.

DECLARATION OF INTEREST

S.S.S. is supported by a European Research Council Consolidator Award (Grant Number 311686) and the National Institute for Health Research (NIHR) Mental Health Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King's College London. The funders had no role in study design, data collection, data analysis, data interpretation or writing of the report.

COPYRIGHT AND USAGE

© The Royal College of Psychiatrists 2017. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) license.

Aberrant Force Processing in Schizophrenia

Initially considered as mere side effects of antipsychotic medication, there is now evidence that motor and somatosensory disturbances precede the onset of the illness and can be found in drug-naive patients. However, research on the topic is scarce. Here, we were interested in assessing the accuracy of the neural signal in detecting parametric variations of force linked to a voluntary motor act and a received tactile sensation, either self-generated or externally generated. Patients with a diagnosis of schizophrenia and healthy controls underwent functional magnetic resonance imaging while asked to press, or abstain from pressing, a lever in order to match a visual target force. Forces, exerted and received, varied on 10 levels from 0.5 N to 5 N in 0.5 N increments. Healthy participants revealed a positive correlation between force and activity in contralateral primary somatosensory area (S1) when performing a movement as well as when receiving a tactile sensation but only when this was externally, and not self-, generated. Patients showed evidence of altered force signaling in both motor and tactile conditions, as well as increased correlation with force when tactile sensation was self-generated. Findings are interpreted in line with accounts of predictive and sensory integration mechanisms and point toward alterations in the encoding of parametric forces in the motor and somatosensory domain in patients affected by schizophrenia.

Effects of a smoking ban on clozapine plasma concentrations in a nonsecure psychiatric unit

BACKGROUND

Tobacco smoke is known to affect plasma levels of some drugs, including the antipsychotic clozapine. The effects of suddenly stopping smoking on patients who take clozapine can be severe, as plasma concentrations are expected to rapidly rise, potentially leading to toxicity. A ban on smoking at South London and the Maudsley NHS Foundation Trust (SLaM) was implemented in 2014, and this was expected to affect the plasma concentrations of clozapine for inpatients at the time. This study aimed to determine whether plasma concentrations of clozapine were affected, and additionally, in line with observations from other authors, whether levels of reported violence would also be affected.

METHODS

The smoking habits of all patients at SLaM who smoked and were prescribed clozapine were recorded both before and after the ban. The Glasgow Antipsychotic Side Effect Scale for Clozapine (GASS-C) scale was used to evaluate side-effect burden. Clozapine doses and plasma concentrations were also collected.

RESULTS

In total, 31 patients were included in this study. The mean clozapine dose before the ban was 502 mg/day, and this did not change significantly after the ban. Similarly, there were no significant changes in clozapine or norclozapine plasma concentrations, or in GASS-C scores. There was no change in the amount of tobacco patients reported smoking before or after the ban. A modest but statistically significant reduction in violent incidences was observed.

CONCLUSIONS

Our data suggest that a ban on smoking for patients taking clozapine on open wards at inpatient hospital sites had little impact on clozapine plasma concentrations, because patients continued to smoke tobacco if allowed to leave. Smoking bans may result in a reduction in violent incidences.

A systematic review of the effects of low-frequency repetitive transcranial magnetic stimulation on cognition

rTMS is increasingly used for a variety of neuropsychiatric conditions. There are data to support 'fast' rTMS (≥10 Hz) having some positive effects on cognitive functioning, but a dearth of research looking at any such effects of 'slow' rTMS. This question is important as cognitive dysfunction accompanies many neuropsychiatric conditions and neuromodulation that potentially enhances or hinders such functioning has important clinical consequences. To determine cognitive effects of slow (≤1 Hz) rTMS, a systematic review of randomized control trials assayed cognition in neurological, psychiatric, and healthy volunteer ≤1 Hz rTMS paradigms. Both active (fast rTMS) and placebo comparators were included. 497 Records were initially obtained; 20 met inclusion criteria for evaluation. Four major categories emerged: mood disorders; psychotic disorders; cerebrovascular accidents; and 'other' (PTSD, OCD, epilepsy, anxiety, and tinnitus). Cognitive effects were measured across several domains: attention, executive functioning, learning, and psychomotor speed. Variability of study paradigms and reporting precluded meta-analytical analysis. No statistically significant improvement or deterioration was consistently found in any cognitive domain or illness category. These data support the overall safety of rTMS in not adversely affecting cognitive functioning. There are some data indicating that rTMS might have cognitive enhancing potential, but these are too limited at this time to make any firm conclusions, and the literature is marked by considerable heterogeneity in study parameters that hinder interpretation. Greater consensus is required in future studies in cognitive markers, and particularly in reporting of protocols. Future work should evaluate the effects of rTMS on cognitive training.

Factors associated with changes in hospitalisation in patients prescribed clozapine

OBJECTIVE

The objective of this study was to examine whether delays in clozapine treatment affect outcomes once clozapine is started and identify factors that affect these outcomes.

METHOD

Patients starting clozapine in a four year period at South London and the Maudsley NHS Foundation Trust were included. Clinical details were gathered from clinical notes. Primary outcome was net change in inpatient admissions comparing the periods before and after clozapine was started.

RESULTS

There was no significant association between the length of clozapine delay (mean clozapine delay = 3.93 years) and number or length of inpatient admissions once clozapine had been started (mean net change in days of admission = 16.74 days), F value = 0.901, p = 0.345. Clozapine reduced the total number of bed days per year, but only if treatment was continued - stopping resulted in inpatient admissions returning to pre-clozapine levels. Younger patients had a greater reduction in bed days when taking clozapine (p = 0.027).

CONCLUSION

Clozapine reduces the number of inpatient days, regardless of the chronicity of the illness at the time clozapine was started. Continued compliance with clozapine is necessary to maintain this benefit. Reduction in bed days is greater in younger patients, suggesting early initiation of clozapine may be beneficial.

A Bayesian model of context-sensitive value attribution

Substantial evidence indicates that incentive value depends on an anticipation of rewards within a given context. However, the computations underlying this context sensitivity remain unknown. To address this question, we introduce a normative (Bayesian) account of how rewards map to incentive values. This assumes that the brain inverts a model of how rewards are generated. Key features of our account include (i) an influence of prior beliefs about the context in which rewards are delivered (weighted by their reliability in a Bayes-optimal fashion), (ii) the notion that incentive values correspond to precision-weighted prediction errors, (iii) and contextual information unfolding at different hierarchical levels. This formulation implies that incentive value is intrinsically context-dependent. We provide empirical support for this model by showing that incentive value is influenced by context variability and by hierarchically nested contexts. The perspective we introduce generates new empirical predictions that might help explaining psychopathologies, such as addiction.

DOI:http://dx.doi.org/10.7554/eLife.16127.001

Learning to trust: trust and attachment in early psychosis

BACKGROUND

Distrust and social dysfunction are characteristic in psychosis and may arise from attachment insecurity, which is elevated in the disorder. The relationship between trust and attachment in the early stages of psychosis is unknown, yet could help to understand interpersonal difficulties and disease progression. This study aimed to investigate whether trust is reduced in patients with early psychosis and whether this is accounted for by attachment avoidance and attachment anxiety.

METHOD

We used two trust games with a cooperative and unfair partner in a sample of 39 adolescents with early psychosis and 100 healthy controls.

RESULTS

Patients had higher levels of attachment anxiety, but the groups did not differ in attachment avoidance. Basic trust was lower in patients than controls, as indicated by lower initial investments. During cooperation patients increased their trust towards levels of controls, i.e. they were able to learn and to override initial suspiciousness. Patients decreased their trust less than controls during unfair interactions. Anxious attachment was associated with higher basic trust and higher trust during unfair interactions and predicted trust independent of group status. Discussion Patients showed decreased basic trust but were able to learn from the trustworthy behaviour of their counterpart. Worries about the acceptance by others and low self-esteem are associated with psychosis and attachment anxiety and may explain behaviour that is focused on conciliation, rather than self-protection.

White Matter Microstructural Organization Is Higher with Age in Adult Superior Cerebellar Peduncles

Using diffusion tensor imaging, we conducted an exploratory investigation of the relationship between white matter tract microstructure and age in 200 healthy adult subjects using tract-based spatial statistics (TBSS). Though most tracts showed the slight decline in microstructural organization with age widely noted, in both superior cerebellar peduncles (SCP) it correlated positively with age, a result not previously reported. We confirmed this by using an alternative method, and by repeating our TBSS analysis in an additional sample of 133 healthy adults. In exploring this surprising result we considered the possibility that this might arise from the continual cognitive and motor refinement that is enacted in the cerebellum: we found that tract microstructure in both SCPs was also strongly correlated with IQ, again in contrast with all other tracts, and its relationship with age mediated by IQ, as a training model would predict.

Dysfunctional Striatal Systems in Treatment-Resistant Schizophrenia

The prevalence of treatment-resistant schizophrenia points to a discrete illness subtype, but to date its pathophysiologic characteristics are undetermined. Information transfer from ventral to dorsal striatum depends on both striato-cortico-striatal and striato-nigro-striatal subcircuits, yet although the functional integrity of the former appears to track improvement of positive symptoms of schizophrenia, the latter have received little experimental attention in relation to the illness. Here, in a sample of individuals with schizophrenia stratified by treatment resistance and matched controls, functional pathways involving four foci along the striatal axis were assessed to test the hypothesis that treatment-resistant and non-refractory patients would exhibit contrasting patterns of resting striatal connectivity. Compared with non-refractory patients, treatment-resistant individuals exhibited reduced connectivity between ventral striatum and substantia nigra. Furthermore, disturbance to corticostriatal connectivity was more pervasive in treatment-resistant individuals. The occurrence of a more distributed pattern of abnormality may contribute to the failure of medication to treat symptoms in these individuals. This work strongly supports the notion of pathophysiologic divergence between individuals with schizophrenia classified by treatment-resistance criteria.

Genome-wide discovered psychosis-risk gene ZNF804A impacts on white matter microstructure in health, schizophrenia and bipolar disorder

Background. Schizophrenia (SZ) and bipolar disorder (BD) have both been associated with reduced microstructural white matter integrity using, as a proxy, fractional anisotropy (FA) detected using diffusion tensor imaging (DTI). Genetic susceptibility for both illnesses has also been positively correlated in recent genome-wide association studies with allele A (adenine) of single nucleotide polymorphism (SNP) rs1344706 of the ZNF804A gene. However, little is known about how the genomic linkage disequilibrium region tagged by this SNP impacts on the brain to increase risk for psychosis. This study aimed to assess the impact of this risk variant on FA in patients with SZ, in those with BD and in healthy controls. Methods. 230 individuals were genotyped for the rs1344706 SNP and underwent DTI. We used tract-based spatial statistics (TBSS) followed by an analysis of variance, with threshold-free cluster enhancement (TFCE), to assess underlying effects of genotype, diagnosis and their interaction, on FA. Results. As predicted, statistically significant reductions in FA across a widely distributed brain network (p < 0.05, TFCE-corrected) were positively associated both with a diagnosis of SZ or BD and with the double (homozygous) presence of the ZNF804A rs1344706 risk variant (A). The main effect of genotype was medium (d = 0.48 in a 44,054-voxel cluster) and the effect in the SZ group alone was large (d = 1.01 in a 51,260-voxel cluster), with no significant effects in BD or controls, in isolation. No areas under a significant diagnosis by genotype interaction were found. Discussion. We provide the first evidence in a predominantly Caucasian clinical sample, of an association between ZNF804A rs1344706 A-homozygosity and reduced FA, both irrespective of diagnosis and particularly in SZ (in overlapping brain areas). This suggests that the previously observed involvement of this genomic region in psychosis susceptibility, and in impaired functional connectivity, may be conferred through it inducing abnormalities in white matter microstructure.

You looking at me?: Interpreting social cues in schizophrenia

BACKGROUND

Deficits in the perception of social cues are common in schizophrenia and predict functional outcome. While effective communication depends on deciphering both verbal and non-verbal features, work on non-verbal communication in the disorder is scarce.

METHOD

This behavioural study of 29 individuals with schizophrenia and 25 demographically matched controls used silent video-clips to examine gestural identification, its contextual modulation and related metacognitive representations.

RESULTS

In accord with our principal hypothesis, we observed that individuals with schizophrenia exhibited a preserved ability to identify archetypal gestures and did not differentially infer communicative intent from incidental movements. However, patients were more likely than controls to perceive gestures as self-referential when confirmatory evidence was ambiguous. Furthermore, the severity of their current hallucinatory experience inversely predicted their confidence ratings associated with these self-referential judgements.

CONCLUSIONS

These findings suggest a deficit in the contextual refinement of social-cue processing in schizophrenia that is potentially attributable to impaired monitoring of a mirror mechanism underlying intentional judgements, or to an incomplete semantic representation of gestural actions. Non-verbal communication may be improved in patients through psychotherapeutic interventions that include performance and perception of gestures in group interactions.

Kaleidoscope

One criticism was that the 12-month follow-up failed to capture a true clinical picture, and that more time was necessary to demonstrate their worth. The team that carried out this original work have now published 3-year data on 330 individuals detained under section of the Mental Health Act,1 randomised on discharge to CTO or voluntary status via Section 17 leave. No improvements in readmission rates, time to first readmission, or duration of readmissions were found for those placed on CTOs. The findings are even more powerful than the original results; CTOs now exist in various forms in over 75 jurisdictions, but no solid scientific evidence has yet been produced to support them. If there are subpopulations for whom (or specific circumstances in which) they work, such characteristics have yet to be delineated. A ‘least restrictive’ principle underpins the Mental Health Act, and a strong rebuttal is needed to justify ongoing CTO use – so-called ‘revolving-door patients' should not be replaced by revolving-door policy.

Kaleidoscope

Life expectancy in England is related to income (and in London, it can be mapped by a resident's nearest tube station1). The arrival of a new government offers the opportunity to review the impact of earlier policies designed to reduce health inequality. A new report from the King's Fund2 has updated Michael Marmot's 2010 publication, Fair Society, Healthy Lives, and using a wider range of determinants of lifestyle and health, has found that income-related inequalities in life expectancy have improved since that report. Department of Health policies in the 2000s appear to have contributed to this, although reductions in child and pensioner poverty and improvements in employment and social housing have also impacted positively. Nevertheless, unemployment, housing deprivation, and binge drinking remain key factors in lowering life expectancy. The King's Fund report argues that a more nuanced and integrated policy response for the NHS and other public services will be required by the new government to continue to reduce inequality, but recognises that implementation in an era of austerity poses challenges, particularly for the most vulnerable.

Kaleidoscope

Palcohol. What is it? It's a powdered alcohol that has recently been approved for sale in the USA.

On the one hand, it is just adding choice, offering a new, crystalline form of one of the world's most commonly used and enjoyed chemicals (although recent news stories1 of some Australians brewing moonshine from Vegemite are surely pushing choice beyond the pale). However, there are some specific challenges with palcohol, which are well articulated in an editorial in JAMA by Naimi & Mosher.2 The powder is sold at 50% alcohol by weight, but the strength by volume will depend on how it is diluted. It can be more easily concealed than liquid alcohol, and it could be added – surreptitiously – to another alcoholic beverage. The potential for misuse, including by children, is self-evident; indeed, a video of an individual eating palcohol has already been uploaded, along with discussions on inhaling it, though such acts appear unlikely to produce intoxication. What is its current status in the UK? Answering a parliamentary question in the House of Lords earlier this year Lord Bates noted3 that ‘The Government is not aware of powdered alcohol being marketed or made available to buy in England and Wales'. However, a very quick and simple check on a well-known internet search engine gave a web-link to buy palcohol online.

Optimising plasma levels of clozapine during metabolic interactions: a review and case report with adjunct rifampicin treatment

BACKGROUND

Clozapine is the only licensed medication for treatment-resistant schizophrenia. The metabolism of clozapine is affected by multiple pharmacokinetic interactions, so the co-administration of adjunct medications can have a significant clinical effect. The anti- tuberculosis medication rifampicin is a potent inducer of the cytochrome P450 system and therefore can cause a reduction in the plasma concentration of clozapine. There is limited clinical evidence regarding co-administration of these medications; in particular there is a lack of data regarding the effect on plasma clozapine levels, which is the key factor determining clinical efficacy. This is clinically relevant given evidence of an increased risk of tuberculosis in patients with schizophrenia.

CASE PRESENTATION

We present a case of a 28 year old British man with a diagnosis of schizoaffective disorder who presented with persistent psychotic symptoms. He developed a systemic inflammatory condition, diagnosed as tuberculosis, and was commenced on a six month course of treatment that included rifampicin. This case presents comprehensive data to illustrate the effect on clozapine plasma levels of a complete course of tuberculosis therapy.

CONCLUSION

This case report provides guidance to clinicians in managing drug interactions between clozapine and rifampicin to enable safe and effective treatment. The co-administration of these medications is likely to increase as the existing underuse of clozapine is recognised whilst the incidence of tuberculosis increases.

Kaleidoscope

Antidepressant effectiveness is a topic seldom out of the scientific or popular press, with claim and counter-claim about the disclosure, reporting, and interpretation of data. Hieronymus and colleagues1 have thrown their hats into the ring: noting that about half of company-sponsored trials failed to show any superiority over placebo, they challenge that most studies evaluated changes in total scores on the 17-point Hamilton Rating Scale for Depression (HRSD-17), but that this might mask improvement in important subcomponents. Not all items equally correlate with illness burden, so they undertook patient-level post hoc analyses focusing on the four-point depressed mood subcomponent in 18 placebo-controlled industry trials of various selective serotonin reuptake inhibitors (n = 6669). The choice of this question was based on its diagnostic importance and the fact it had the highest baseline severity in the pooled sample. The result was that 91% of comparisons showed superiority of the active drug over placebo, compared with 46% where the summed scale was used (P<0.001). The authors argue that the summed scale is insensitive, and clouds current views on medications. The end of the debate? We think not …

Skating on thin ice: pragmatic prescribing for medication refractory schizophrenia

BACKGROUND

Clozapine is the treatment of choice for medication refractory psychosis, but it does not benefit half of those put on it. There are numerous studies of potential post-clozapine strategies, but little data to guide the order of such treatment in this common clinical challenge. We describe a naturalistic observational study in 153 patients treated by a specialist psychosis service to identify optimal pharmacotherapy practice, based on outcomes.

METHODS

Medication and clinical data, based on the OPCRIT tool, were examined on admission and discharge from the national psychosis service. The primary outcome measure was the percentage change in mental state examination symptoms between admission and discharge and the association with medication on discharge. Exploratory analyses evaluated the specificity of individual medication effects on symptom clusters.

RESULTS

There were fewer drugs prescribed at discharge relative to admission, suggesting an optimisation of medication, and a doubling of the number of patients treated with clozapine. Treatment with clozapine on discharge was associated with maximal decrease in symptoms from admission. In the group of patients that did not respond to clozapine monotherapy, the most effective drug combinations were clozapine augmentation with 1) sodium valproate, 2) lithium, 3) amisulpride, and 4) quetiapine. There was no support for a dose-response relationship for any drug combination.

CONCLUSIONS

Clozapine monotherapy is clearly the optimal medication in medication refractory schizophrenia and it is possible to maximise its use. In patients unresponsive to clozapine monotherapy, augmentation with sodium valproate, lithium, amisulpride and quetiapine, in that order, is a reasonable treatment algorithm. Reducing the number of ineffective drugs is possible without a detrimental effect on symptoms. Exploratory data indicated that clozapine was beneficial across a range of symptoms domains, whereas olanzapine was beneficial specifically for hallucinations and lamotrigine for comorbid affective symptoms.

Self-harm and suicidal acts: a suitable case for treatment of impulsivity-driven behaviour with repetitive transcranial magnetic stimulation (rTMS)

SUMMARY

Suicidal thinking, self-harm and suicidal acts are common, although determining their precise prevalence is complex. Epidemiological work has identified a number of associated demographic and clinical factors, though, with the exception of past acts of self-harm, these are non-specific and weak future predictors. There is a critical need shift focus from managing 'suicidality-by-proxy' through general mental health treatments, to better understand the neuropsychology and neurophysiology of such behaviour to guide targeted interventions. The model of the cognitive control of emotion (MCCE) offers such a paradigm, with an underlying pan-diagnostic pathophysiology of a hypoactive prefrontal cortex failing to suitably inhibit an overactive threat-responding limbic system. The result is a phenotype - from any number of causative gene-environment interactions - primed to impulsively self-harm. We argue that such neural dysconnectivity is open to potential therapeutic modification from repetitive transcranial magnetic stimulation (rTMS). The current evidence base for this is undoubtedly extremely limited, but the societal and clinical burden self-harm and suicide pose warrants such investigation.

DECLARATION OF INTEREST

K.B. is the Editor of BJPsych Open, but had no editorial involvement in the review or decision process regarding this paper.

COPYRIGHT AND USAGE

© The Royal College of Psychiatrists 2015. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) licence.

Social neuroscience in psychiatry: unravelling the neural mechanisms of social dysfunction

Social neuroscience is a flourishing, interdisciplinary field that investigates the underlying biological processes of social cognition and behaviour. The recent application of social neuroscience to psychiatric research advances our understanding of various psychiatric illnesses that are characterized by impairments in social cognition and social functioning. In addition, the upcoming line of social neuroscience research provides new techniques to design and evaluate treatment interventions that are aimed at improving patients' social lives. This review provides a contemporary overview of social neuroscience in psychiatry. We draw together the major findings about the neural mechanisms of social cognitive processes directed at understanding others and social interactions in psychiatric illnesses and discuss their implications for future research and clinical practice.

Prevalence of serum N-methyl-D-aspartate receptor autoantibodies in refractory psychosis

N-methyl-d-aspartate receptor (NMDA-R) autoantibodies have been reported in people with acute psychosis. We hypothesised that their presence may be implicated in the aetiology of treatment-refractory psychosis. We sought to ascertain the point prevalence of NMDA-R antibody positivity in patients referred to services for treatment-refractory psychosis. We found that 3 (7.0%) of 43 individuals had low positive NMDA-R antibody titres. This suggests that NMDA-R autoantibodies are unlikely to account for a large proportion of treatment-refractory psychosis.

Dementia praecox redux: a systematic review of the nicotinic receptor as a target for cognitive symptoms of schizophrenia

Most individuals with schizophrenia suffer some cognitive dysfunction: such deficits are predictive of longer-term functioning; and current dopamine-blocking antipsychotics have made little impact on this domain. There is a pressing need to develop novel pharmacological agents to tackle this insidious but most disabling of problems. The acetylcholinergic system is involved in cognitive and attentional processing, and its metabotropic and nicotinic receptors are widespread throughout the brain. Deficits in acetylcholinergic functioning occur in schizophrenia, and high rates of tobacco smoking have been posited to represent a form of self-medication. The nicotinic acetylcholine receptor (nAChR) has emerged as a putative target to improve cognitive deficits in schizophrenia, and this study systematically reviewed the emerging data. Nineteen studies were identified, covering three compound classes: agonists at the α7 and α 4β2 nAChRs, and positive allosteric modulators. Overall data are underwhelming: some studies showed significant improvements in cognition but as many studies had negative findings. It remains unclear if this represents drug limitations or nascent study methodology problems. The literature is particularly hindered by variability in inclusion of smokers, generally small sample sizes, and a lack of consensus on cognitive test batteries. Future work should evaluate longer-term outcomes, and, particularly, the effects of concomitant cognitive training.

Impaired subjective well-being in schizophrenia is associated with reduced anterior cingulate activity during reward processing

BACKGROUND

Patients with schizophrenia have substantially reduced subjective well-being (SW) compared to healthy individuals. It has been suggested that diminished SW may be related to deficits in the neural processing of reward but this has not been shown directly. We hypothesized that, in schizophrenia, lower SW would be associated with attenuated reward-related activation in the reward network.

METHOD

Twenty patients with schizophrenia with a range of SW underwent a functional magnetic resonance imaging (fMRI) reward task. The brain activity underlying reward anticipation and outcome in schizophrenia was examined and compared to that of 12 healthy participants using a full factorial analysis. Region of interest (ROI) analyses of areas within the reward network and whole-brain analyses were conducted to reveal neural correlates of SW.

RESULTS

Reward-related neural activity in schizophrenia was not significantly different from that of healthy participants; however, the patients with schizophrenia showed significantly diminished SW. Both ROI and whole-brain analyses confirmed that SW scores in the patients correlated significantly with activity, specifically in the dorsal anterior cingulate cortex (dACC), during both reward anticipation and reward outcome. This association was not seen in the healthy participants.

CONCLUSIONS

In patients with schizophrenia, reduced activation of the dACC during multiple aspects of reward processing is associated with lower SW. As the dACC has been widely linked to coupling of reward and action, and the link to SW is apparent over anticipation and outcome, these findings suggest that SW deficits in schizophrenia may be attributable to reduced integration of environmental rewarding cues, motivated behaviour and reward outcome.

Reduced brain reward response during cooperation in first-degree relatives of patients with psychosis: an fMRI study

BACKGROUND

Psychosis is characterized by a profound lack of trust and disturbed social interactions. Investigating the neural basis of these deficits is difficult because of medication effects but first-degree relatives show qualitatively similar abnormalities to patients with psychosis on various tasks. This study aimed to investigate neural activation in siblings of patients in response to an interactive task. We hypothesized that, compared to controls, siblings would show (i) less basic trust at the beginning of the task and (ii) reduced activation of the brain reward and mentalizing systems.

METHOD

Functional magnetic resonance imaging (fMRI) data were acquired on 50 healthy siblings of patients with psychosis and 33 healthy controls during a multi-round trust game with a cooperative counterpart. An a priori region-of-interest (ROI) analysis of the caudate, temporoparietal junction (TPJ), superior temporal sulcus (STS), insula and medial prefrontal cortex (mPFC) was performed focusing on the investment and repayment phases. An exploratory whole-brain analysis was run to test for group-wise differences outside these ROIs.

RESULTS

The siblings' behaviour during the trust game did not differ significantly from that of the controls. At the neural level, siblings showed reduced activation of the right caudate during investments, and the left insula during repayments. In addition, the whole-brain analysis revealed reduced putamen activation in siblings during investments.

CONCLUSIONS

The findings suggest that siblings show aberrant functioning of regions traditionally involved in reward processing in response to cooperation, which may be associated with the social reward deficits observed in psychosis.

Kaleidoscope

It cannot have escaped our readers' notice that there has been a public increase in the awareness of the impact of dementia on people's lives: politicians have raised concerns about a dementia ‘time bomb’ as a greater number of people live to an older age; and even the 2013 G8 summit declared1 that there was a need for international initiatives to tackle this illness. The inevitable call for more research is underscored by the lack of any new licenced medications for Alzheimer's disease since 2002. There has been much interest in a putative role for statins – which inhibit the HMGCR enzyme, the rate-limiting step in cholesterol production – as retrospective epidemiological data have shown that they can reduce the risk of developing Alzheimer's disease by up to 70%; but, frustratingly, administration of these drugs to those with the illness appears to produce little benefit. Recent data have now shown that the gene encoding this HMGCR enzyme is a potent modifier for the age at onset and rate of conversion from mild cognitive impairment to Alzheimer's disease.2 Indeed, this work would indicate that its G-negative allele is second only to APOE2 as the most common and important protective genetic variant for spontaneous Alzheimer's disease.

Unheard voices: outcomes of tertiary care for treatment-refractory psychosis

Aims and method In up to a quarter of patients, schizophrenia is resistant to standard treatments. We undertook a naturalistic study of 153 patients treated in the tertiary referral in-patient unit of the National Psychosis Service based at the Maudsley Hospital in London. A retrospective analysis of symptoms on admission and discharge was undertaken using the OPCRIT tool, along with preliminary economic modelling of potential costs related to changes in accommodation.

Results In-patient treatment demonstrated statistically significant improvements in all symptom categories in patients already identified as having schizophrenia refractory to standard secondary care. The preliminary cost analysis showed net savings to referring authorities due to changes from pre- to post-discharge accommodation.

Clinical implications Despite the enormous clinical, personal and societal burden of refractory psychotic illnesses, there is insufficient information on the outcomes of specialised tertiary-level care. Our pilot data support its utility in all domains measured.

Eluding the illusion? Schizophrenia, dopamine and the McGurk effect

Perceptions are inherently probabilistic; and can be potentially manipulated to induce illusory experience by the presentation of ambiguous or improbable evidence under selective (spatio-temporal) constraints. Accordingly, perception of the McGurk effect, by which individuals misperceive specific incongruent visual and auditory vocal cues, rests upon effective probabilistic inference. Here, we report findings from a behavioral investigation of illusory perception and related metacognitive evaluation during audiovisual integration, conducted in individuals with schizophrenia (n = 30) and control subjects (n = 24) matched in terms of age, sex, handedness and parental occupation. Controls additionally performed the task after an oral dose of amisulpride (400 mg). Individuals with schizophrenia were observed to exhibit illusory perception less frequently than controls, despite non-significant differences in perceptual performance during control conditions. Furthermore, older individuals with schizophrenia exhibited reduced rates of illusory perception. Subsequent analysis revealed a robust inverse relationship between illness chronicity and the illusory perception rate in this group. Controls demonstrated non-significant modulation of perception by amisulpride; amisulpride was, however, found to elicit increases in subjective confidence in perceptual performance. Overall, these findings are consistent with the idea that impairments in probabilistic inference are exhibited in schizophrenia and exacerbated by illness chronicity. The latter suggests that associated processes are a potentially worthwhile target for therapeutic intervention.

Amphetamine sensitization alters reward processing in the human striatum and amygdala

Dysregulation of mesolimbic dopamine transmission is implicated in a number of psychiatric illnesses characterised by disruption of reward processing and goal-directed behaviour, including schizophrenia, drug addiction and impulse control disorders associated with chronic use of dopamine agonists. Amphetamine sensitization (AS) has been proposed to model the development of this aberrant dopamine signalling and the subsequent dysregulation of incentive motivational processes. However, in humans the effects of AS on the dopamine-sensitive neural circuitry associated with reward processing remains unclear. Here we describe the effects of acute amphetamine administration, following a sensitising dosage regime, on blood oxygen level dependent (BOLD) signal in dopaminoceptive brain regions during a rewarded gambling task performed by healthy volunteers. Using a randomised, double-blind, parallel-groups design, we found clear evidence for sensitization to the subjective effects of the drug, while rewarded reaction times were unchanged. Repeated amphetamine exposure was associated with reduced dorsal striatal BOLD signal during decision making, but enhanced ventromedial caudate activity during reward anticipation. The amygdala BOLD response to reward outcomes was blunted following repeated amphetamine exposure. Positive correlations between subjective sensitization and changes in anticipation- and outcome-related BOLD signal were seen for the caudate nucleus and amygdala, respectively. These data show for the first time in humans that AS changes the functional impact of acute stimulant exposure on the processing of reward-related information within dopaminoceptive regions. Our findings accord with pathophysiological models which implicate aberrant dopaminergic modulation of striatal and amygdala activity in psychosis and drug-related compulsive disorders.

Ketamine as the prototype glutamatergic antidepressant: pharmacodynamic actions, and a systematic review and meta-analysis of efficacy

The burden of depressive disorders and the frequent inadequacy of their current pharmacological treatments are well established. The anaesthetic and hallucinogenic drug ketamine has provoked much interest over the past decade or so as an extremely rapidly acting antidepressant that does not modify 'classical' monoaminergic receptors. Current evidence has shown several ways through which it might exert therapeutic antidepressant actions: blockade of glutamatergic NMDA receptors and relative upregulation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) subtypes may alter cortical connectivity patterns; through intracellular changes in protein expression, including the proteins mammalian target of rapamycin (mTOR) and brain-derived neurotrophic factor (BDNF); and alteration of intracellular signalling cascades. The clinical evidence demonstrates rapid improvements in mood and suicidal thinking in most participants, although study numbers have generally been small and many trials are unblinded and methodologically weak. There is a small body of work to suggest ketamine might also augment electroconvulsive therapy and potentially have a role as a surgical anaesthetic in depressed patients. A major problem is that the effects of ketamine appear temporary, disappearing after days to weeks (although longer benefits have been sustained in some), and attempts to circumvent this through pharmacological augmentation have been disappointing thus far. These exciting data are providing new insights into neurobiological models of depression, and potentially opening up a new class of antidepressants, but there are significant practical and ethical issues about any future mainstream clinical role it might have.

Functional magnetic resonance imaging of impaired sensory prediction in schizophrenia

IMPORTANCE

Forward models predict the sensory consequences of planned actions and permit discrimination of self- and non-self-elicited sensation; their impairment in schizophrenia is implied by an abnormality in behavioral force-matching and the flawed agency judgments characteristic of positive symptoms, including auditory hallucinations and delusions of control.

OBJECTIVE

To assess attenuation of sensory processing by self-action in individuals with schizophrenia and its relation to current symptom severity.

DESIGN, SETTING, AND PARTICIPANTS

Functional magnetic resonance imaging data were acquired while medicated individuals with schizophrenia (n = 19) and matched controls (n = 19) performed a factorially designed sensorimotor task in which the occurrence and relative timing of action and sensation were manipulated. The study took place at the neuroimaging research unit at the Institute of Cognitive Neuroscience, University College London, and the Maudsley Hospital.

RESULTS

In controls, a region of secondary somatosensory cortex exhibited attenuated activation when sensation and action were synchronous compared with when the former occurred after an unexpected delay or alone. By contrast, reduced attenuation was observed in the schizophrenia group, suggesting that these individuals were unable to predict the sensory consequences of their own actions. Furthermore, failure to attenuate secondary somatosensory cortex processing was predicted by current hallucinatory severity.

CONCLUSIONS AND RELEVANCE

Although comparably reduced attenuation has been reported in the verbal domain, this work implies that a more general physiologic deficit underlies positive symptoms of schizophrenia.

Examining belief and confidence in schizophrenia

BACKGROUND

People with psychoses often report fixed, delusional beliefs that are sustained even in the presence of unequivocal contrary evidence. Such delusional beliefs are the result of integrating new and old evidence inappropriately in forming a cognitive model. We propose and test a cognitive model of belief formation using experimental data from an interactive 'Rock Paper Scissors' (RPS) game.

METHOD

Participants (33 controls and 27 people with schizophrenia) played a competitive, time-pressured interactive two-player game (RPS). Participants' behavior was modeled by a generative computational model using leaky integrator and temporal difference methods. This model describes how new and old evidence is integrated to form a playing strategy to beat the opponent and to provide a mechanism for reporting confidence in one's playing strategy to win against the opponent.

RESULTS

People with schizophrenia fail to appropriately model their opponent's play despite consistent (rather than random) patterns that can be exploited in the simulated opponent's play. This is manifest as a failure to weigh existing evidence appropriately against new evidence. Furthermore, participants with schizophrenia show a 'jumping to conclusions' (JTC) bias, reporting successful discovery of a winning strategy with insufficient evidence.

CONCLUSIONS

The model presented suggests two tentative mechanisms in delusional belief formation: (i) one for modeling patterns in other's behavior, where people with schizophrenia fail to use old evidence appropriately, and (ii) a metacognitive mechanism for 'confidence' in such beliefs, where people with schizophrenia overweight recent reward history in deciding on the value of beliefs about the opponent.

Mechanisms Underlying Auditory Hallucinations-Understanding Perception without Stimulus

Auditory verbal hallucinations (AVH) are a common phenomenon, occurring in the “healthy” population as well as in several mental illnesses, most notably schizophrenia. Current thinking supports a spectrum conceptualisation of AVH: several neurocognitive hypotheses of AVH have been proposed, including the “feed-forward” model of failure to provide appropriate information to somatosensory cortices so that stimuli appear unbidden, and an “aberrant memory model” implicating deficient memory processes. Neuroimaging and connectivity studies are in broad agreement with these with a general dysconnectivity between frontotemporal regions involved in language, memory and salience properties. Disappointingly many AVH remain resistant to standard treatments and persist for many years. There is a need to develop novel therapies to augment existing pharmacological and psychological therapies: transcranial magnetic stimulation has emerged as a potential treatment, though more recent clinical data has been less encouraging. Our understanding of AVH remains incomplete though much progress has been made in recent years. We herein provide a broad overview and review of this.

Reduced crowding and poor contour detection in schizophrenia are consistent with weak surround inhibition

BACKGROUND

Detection of visual contours (strings of small oriented elements) is markedly poor in schizophrenia. This has previously been attributed to an inability to group local information across space into a global percept. Here, we show that this failure actually originates from a combination of poor encoding of local orientation and abnormal processing of visual context.

METHODS

We measured the ability of observers with schizophrenia to localise contours embedded in backgrounds of differently oriented elements (either randomly oriented, near-parallel or near-perpendicular to the contour). In addition, we measured patients' ability to process local orientation information (i.e., report the orientation of an individual element) for both isolated and crowded elements (i.e., presented with nearby distractors).

RESULTS

While patients are poor at detecting contours amongst randomly oriented elements, they are proportionally less disrupted (compared to unaffected controls) when contour and surrounding elements have similar orientations (near-parallel condition). In addition, patients are poor at reporting the orientation of an individual element but, again, are less prone to interference from nearby distractors, a phenomenon known as visual crowding.

CONCLUSIONS

We suggest that patients' poor performance at contour perception arises not as a consequence of an "integration deficit" but from a combination of reduced sensitivity to local orientation and abnormalities in contextual processing. We propose that this is a consequence of abnormal gain control, a phenomenon that has been implicated in orientation-selectivity as well as surround suppression.

Dysregulated but not decreased salience network activity in schizophrenia

Effective estimation of the salience of environmental stimuli underlies adaptive behavior, while related aberrance is believed to undermine rational thought processes in schizophrenia. A network including bilateral frontoinsular cortex (FIC) and dorsal anterior cingulate cortex (dACC) has been observed to respond to salient stimuli using functional magnetic resonance imaging (fMRI). To test the hypothesis that activity in this salience network (SN) is less discriminately modulated by contextually-relevant stimuli in schizophrenia than in healthy individuals, fMRI data were collected in 20 individuals with schizophrenia and 13 matched controls during performance of a modified monetary incentive delay (MID) task. After quantitatively identifying spatial components representative of the FIC and dACC features of the SN, two principal analyses were conducted. In the first, modulation of SN activity by salience was assessed by measuring response to trial outcome. First-level general linear models were applied to individual-specific time-courses of SN activity identified using spatial independent component analysis (ICA). This analysis revealed a significant salience-by-performance-by-group interaction on the best-fit FIC component's activity at trial outcome, whereby healthy individuals but not individuals with schizophrenia exhibited greater distinction between the response to hits and misses in high salience trials than in low salience trials. The second analysis aimed to ascertain whether SN component amplitude differed between the study groups over the duration of the experiment. Independent-samples T-tests on back-projected, percent-signal-change scaled SN component images importantly showed that the groups did not differ in the overall amplitude of SN expression over the entire dataset. These findings of dysregulated but not decreased SN activity in schizophrenia provide physiological support for mechanistic conceptual frameworks of delusional thought formation.