Brain Imaging in Adolescents and Young Adults With First-Episode Psychosis: A Retrospective Cohort Study

OBJECTIVE

Despite the lack of clear guidelines, neuroimaging (computed tomography [CT] or magnetic resonance imaging [MRI]) is frequently performed in subjects presenting with first-episode psychosis (FEP). The objective of this study was to determine if the use of neuroimaging adds diagnostic yield in adolescents and young adults presenting with FEP.

METHODS

The sample consisted of 443 subjects aged 15-24 with FEP (DSM-IV-TR and DSM-5) and no focal neurologic findings. Consecutive charts from January 1, 1998, to June 30, 2016, were reviewed retrospectively. A positive finding was defined as a result leading to urgent follow-up or intervention.

RESULTS

Twenty-five (5.6%) of 443 subjects showed incidental findings unrelated to psychosis. The prevalence of positive findings from neuroimaging was 0%, indicating no diagnostic yield from neuroimaging.

CONCLUSIONS

Routine neuroimaging did not provide diagnostic information leading to a change in clinical management and should not be recommended in the investigation of FEP.

Canadian Guidelines for the Pharmacological Treatment of Schizophrenia Spectrum and Other Psychotic Disorders in Children and Youth

OBJECTIVE

Schizophrenia spectrum and other psychotic disorders often have their onset in adolescence. The sequelae of these illnesses can negatively alter the trajectory of emotional, cognitive, and social development in children and youth if left untreated. Early and appropriate interventions can improve outcomes. This article aims to identify best practices in the pharmacotherapy management of children and youth with schizophrenia spectrum disorders.

METHODS

A systematic search was conducted for published guidelines for schizophrenia and schizophrenia spectrum disorders in children and youth (under age 18 years). Recommendations were drawn from the National Institute for Health and Care Excellence guidelines on psychosis and schizophrenia in children and youth (2013 and 2015 updates). Current guidelines were adopted using the ADAPTE process, which includes consensus ratings by a panel of experts.

RESULTS

Recommendations identified covered a range of issues in the pharmacotherapy management of children and youth with schizophrenia spectrum disorders. Further work in this area is warranted as we continue to further understand their presentation in the developing brain.

CONCLUSIONS

Canadian guidelines for the pharmacotherapy management of children and youth with schizophrenia spectrum disorders are essential to assist clinicians in treating this vulnerable population. Ongoing work in this area is recommended.

Guidelines for the Pharmacotherapy of Schizophrenia in Adults

OBJECTIVE

The present guidelines address the pharmacotherapy of schizophrenia in adults across different stages, phases, and symptom domains.

METHOD

Guidelines were developed using the ADAPTE process, which takes advantage of existing guidelines. Six guidelines were identified for adaptation, with recommendations extracted from each. For those specific to the pharmacotherapy of schizophrenia in adults, a working group selected between guidelines and recommendations to create an adapted guideline.

RESULTS

Recommendations can be categorized into 6 areas that include 1) first-episode schizophrenia, 2) acute exacerbation, 3) relapse prevention and maintenance treatment, 4) treatment-resistant schizophrenia, 5) clozapine-resistant schizophrenia, and 6) specific symptom domains. For each category, recommendations are made based on the available evidence, which is discussed and linked to other established guidelines.

CONCLUSIONS

In most cases, evidence-based recommendations are made that can be used to guide current clinical treatment and decision making. Notably, however, there is a paucity of established evidence to guide treatment decision making in the case of clozapine-resistant schizophrenia, a subsample that represents a sizable proportion of those with schizophrenia.

Canadian Treatment Guidelines for Individuals at Clinical High Risk of Psychosis

OBJECTIVE

Young people who are at clinical high risk (CHR) of developing psychosis are often help seeking and have significant distress and dysfunction. There are limited guidelines for the assessment and treatment for this population. The aim of this guideline was to develop treatment recommendations for this at-risk group.

METHOD

A systematic search was conducted for published guidelines for CHR. All current guidelines for schizophrenia were reviewed for treatment guidelines on individuals at CHR. The recommendations adopted were primarily drawn from the European Psychiatric Association (EPA) guidance on the early intervention in clinical high-risk states of psychoses and the 2014 National Institute for Health and Care Excellence (NICE) guidelines on the treatment and management of those at CHR for psychosis.

RESULTS

After the guideline development process described, 9 recommendations were developed based on the quality of evidence, appropriateness for the Canadian health care system, and clinical expert consensus.

CONCLUSIONS

Assessment by an expert in the field was the first recommendation. It was recommended that treatment follow a staged approach with psychological treatments being the first-line treatment and pharmacotherapy reserved for adults, those who did not respond to psychological interventions, and those who had more severe symptoms.

Pathological gambling is linked to reduced activation of the mesolimbic reward system

By analogy to drug dependence, it has been speculated that the underlying pathology in pathological gambling is a reduction in the sensitivity of the reward system. Studying pathological gamblers and controls during a guessing game using functional magnetic resonance imaging, we observed a reduction of ventral striatal and ventromedial prefrontal activation in the pathological gamblers that was negatively correlated with gambling severity, linking hypoactivation of these areas to disease severity.

The Face of Pain - A Pilot Study to Validate the Measurement of Facial Pain Expression with an Improved EMG Method

OBJECTIVE: The purpose of this pilot study was to establish the validity of an improved facial electromyogram (EMG) method for the measurement of facial pain expression.

BACKGROUND: Darwin defined pain in connection with fear as a simultaneous occurrence of eye staring, brow contraction and teeth chattering. Prkachin was the first to use the video-based Facial Action Coding System to measure facial expressions while using four different types of pain triggers, identifying a group of facial muscles around the eyes.

METHOD: The activity of nine facial muscles in 10 healthy male subjects was analyzed. Pain was induced through a laser system with a randomized sequence of different intensities. Muscle activity was measured with a new, highly sensitive and selective facial EMG.

RESULTS: The results indicate two groups of muscles as key for pain expression. These results are in concordance with Darwin's definition. As in Prkachin's findings, one muscle group is assembled around the orbicularis oculi muscle, initiating eye staring. The second group consists of the mentalis and depressor anguli oris muscles, which trigger mouth movements.

CONCLUSIONS: The results demonstrate the validity of the facial EMG method for measuring facial pain expression. Further studies with psychometric measurements, a larger sample size and a female test group should be conducted.

White Matter Asymmetry in the Human Brain: A Diffusion Tensor MRI Study

Language ability and handedness are likely to be associated with asymmetry of the cerebral cortex (grey matter) and connectivity (white matter). Grey matter asymmetry, most likely linked to language has been identified with voxel-based morphometry (VBM) using T(1)-weighted images. Differences in white matter obtained with this technique are less consistent, probably due to the relative insensitivity of the T(1) contrast to the ultrastructure of white matter. Furthermore, previous VBM studies failed to find differences related to handedness in either grey or white matter. We revisited these issues and investigated two independent groups of subjects with diffusion-tensor imaging (DTI) for asymmetries in white matter composition. Using voxel-based statistical analyses an asymmetry of the arcuate fascicle was observed, with higher fractional anisotropy in the left hemisphere. In addition, we show differences related to handedness in the white matter underneath the precentral gyrus contralateral to the dominant hand. Remarkably, these findings were very robust, even when investigating small groups of subjects. This highlights the sensitivity of DTI for white matter tissue differences, making it an ideal tool to study small patient populations.

P300 and genetic risk for schizophrenia

BACKGROUND

We assessed the suitability of event-related potential frontal and temporoparietal P300 changes as intermediate phenotypes in genetic studies of schizophrenia. We applied a principal component analysis approach based on the notion that P300 abnormalities in siblings of schizophrenic patients may involve a widespread network of relatively weak cortical generators and because an earlier, smaller study that used a topographic analysis of covariance model did not show that localized P300 changes predict risk for schizophrenia.

METHODS

P300 changes in 66 schizophrenic patients, 115 healthy siblings of schizophrenic patients, and 89 unrelated controls were studied during a standard auditory oddball paradigm. Principal components were calculated across electrodes, revealing frontal and temporoparietal components for latency and amplitude, respectively. For the frontal and temporoparietal P300 amplitude and latency components, the intraclass correlations (ICCs) between sib-pairs (pairs of unaffected siblings and schizophrenic index patients) and the relative risk ratios (lambda) were determined.

RESULTS

Compared with controls, schizophrenic patients and their unaffected siblings showed significant reductions in the temporoparietal P300 amplitude component. Both groups were also characterized by a significantly higher frontal P300 amplitude component. Significant ICCs and increased relative risk ratios were found for the frontal (ICCU = 0.18; P =.04; lambda = 3.4) and temporoparietal (ICCU = 0.24; P =.01; lambda = 1.7) P300 amplitude components.

CONCLUSIONS

Temporoparietal P300 amplitude reduction and frontal P300 amplitude increase seem to be quantitative phenotypes associated with increased risk of schizophrenia. Both measures may be useful for increasing the statistical power of genetic studies of schizophrenia.

Neuropharmacological studies with SPECT in neuropsychiatric disorders

The last decade saw a rapid development of single photon emission computed tomography (SPECT) from a tool to assess cerebral blood flow to the study of specific neurotransmitter systems. Because of the relatively long half-life of SPECT radioisotopes, it is practical to measure the availability of neuroreceptors and transporters in conditions approaching equilibrium. The cost-efficiency of SPECT allowed studies in relatively large samples of patients with various neuropsychiatric disorders. We have applied this approach in studies of dopaminergic, serotonergic, and muscarinergic neurotransmission in patients with dementia, extrapyramidal disorders, schizophrenia, and alcoholism. No simple associations were observed between a single defect in one neurotransmitter system and a certain neuropsychiatric disease. Instead, complex dysfunction of several neurotransmitter systems in multiple, partially connected brain circuits have been implicated. Treatment effects also have been characterized. Microdialysis and neurotransmitter depletion studies showed that most radioligands and endogenous neurotransmitters compete for binding at receptors and transporters. Future research directions include the assessment of endogenous neurotransmitter concentrations measured by depletion studies and of genetic effects on neuroreceptor and transporter expression.

Extrapyramidal side effects with risperidone and haloperidol at comparable D2 receptor occupancy levels

Risperidone is an antipsychotic drug with high affinity at dopamine D2 and serotonin 5-HT2 receptors. Previous clinical studies have proposed that risperidone's pharmacologic profile may produce improved efficacy for negative psychotic symptoms and decreased propensity for extrapyramidal side effects; features shared by so-called 'atypical' neuroleptics. To determine if routine risperidone treatment is associated with a unique degree of D2 receptor occupancy and pattern of clinical effects, we used [123I]IBZM SPECT to determine D2 occupancy in subjects treated with routine clinical doses of risperidone (n = 12) or haloperidol (n = 7). Both risperidone and haloperidol produced D2 occupancy levels between approximately 60 and 90% at standard clinical doses. There was no significant difference between occupancy levels obtained with haloperidol or risperidone. Drug-induced parkinsonism was observed in subjects treated with risperidone (42%) and haloperidol (29%) and was observed at occupancy levels above 60%. Based on these observations, it is concluded that 5-HT2 blockade obtained with risperidone at D2 occupancy rates of 60% and above does not appear to protect against the risk for extrapyramidal side effects.