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CONTEXT Schizophrenic symptoms are linked to a dysfunction of dopamine neurotransmission and the brain reward system. However, it remains unclear whether antipsychotic treatment, which blocks dopamine transmission, improves, alters, or even worsens the reward-related abnormalities. OBJECTIVE To investigate changes in reward-related brain activations in schizophrenia before and after antipsychotic monotherapy with a dopamine D2/D3 antagonist. DESIGN Longitudinal cohort study. SETTING Psychiatric inpatients and outpatients in the Capital Region of Denmark. PARTICIPANTS Twenty-three antipsychotic-naive patients with first-episode schizophrenia and 24 healthy controls initially matched on age, sex, and parental socioeconomic status were examined with functional magnetic resonance imaging while playing a variant of the monetary incentive delay task. INTERVENTIONS Patients were treated for 6 weeks with the antipsychotic compound amisulpride. Controls were followed up without treatment. MAIN OUTCOME MEASURES Task-related blood oxygen level-dependent activations as measured by functional magnetic resonance imaging before and after antipsychotic treatment. RESULTS At baseline, patients, as compared with controls, demonstrated an attenuation of brain activation during reward anticipation in the ventral striatum, bilaterally. After 6 weeks of treatment, patients showed an increase in the anticipation-related functional magnetic resonance imaging signal and were no longer statistically distinguishable from healthy controls. Among the patients, there was a correlation between the improvement of positive symptoms and normalization of reward-related activation. Those who showed the greatest clinical improvement in positive symptoms also showed the greatest increase in reward-related activation after treatment. CONCLUSIONS To our knowledge, this is the first controlled, longitudinal study of reward disturbances in schizophrenic patients before and after their first antipsychotic treatment. Our results demonstrate that alterations in reward processing are fundamental to the illness and are seen prior to any treatment. Antipsychotic treatment tends to normalize the response of the reward system; this was especially seen in the patients with the most pronounced treatment effect on the positive symptoms. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01154829.

AimsSchizophrenia is associated with cardiovascular co‐morbidity and a reduced life‐expectancy of up to 20 years. Antipsychotics are dopamine D2 receptor antagonists and are the standard of medical care in schizophrenia, but the drugs are associated with severe metabolic side effects such as obesity and diabetes. Glucagon‐like peptide‐1 receptor agonists (GLP‐1RAs) are registered for treatment of both obesity and type 2 diabetes. We investigated metabolic effects of the GLP‐1RA, exenatide once‐weekly, in non‐diabetic, antipsychotic‐treated, obese patients with schizophrenia.Material and methodsAntipsychotic‐treated, obese, non‐diabetic, schizophrenia spectrum patients were randomized to double‐blinded adjunctive treatment with once‐weekly subcutaneous exenatide (n = 23) or placebo (n = 22) injections for 3 months. The primary outcome was loss of body weight after treatment and repeated measures analysis of variance was used as statistical analysis.ResultsBetween March 2013 and June 2015, 40 patients completed the trial. At baseline, mean body weight was 118.3 ± 16.0 kg in the exenatide group and 111.7 ± 18.0 kg in the placebo group, with no group differences ( P = .23). The exenatide and placebo groups experienced significant ( P = .004), however similar ( P = .98), weight losses of 2.24 ± 3.3 and 2.23 ± 4.4 kg, respectively, after 3 months of treatment.ConclusionsTreatment with exenatide once‐weekly did not promote weight loss in obese, antipsychotic‐treated patients with schizophrenia compared to placebo. Our results could suggest that the body weight‐lowering effect of GLP‐1RAs involves dopaminergic signaling, but blockade of other receptor systems may also play a role. Nevertheless, anti‐obesity regimens effective in the general population may not be readily implemented in antipsychotic‐treated patients with schizophrenia.

GLP-1RAs are effective and tolerable for antipsychotic-associated body weight gain, particularly clozapine/olanzapine-treated patients. With few included patients, further studies are required before making routine use recommendations for GLP-1RAs.

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ObjectivePatients at ultra-high risk (UHR) for psychosis show significant impairments in functioning. It is essential to determine which factors influence functioning, as it may have implications for intervention strategies. This study examined whether social cognitive abilities and clinical symptoms are associated with functioning and social skills.MethodsThe study included 65 UHR patients and 30 healthy controls. Social cognitive function, social skills, and a broad range of functioning measures were assessed.ResultsThe UHR patients demonstrated significant decrements on The Awareness of Social Inferences Task total score (p = .046, d = .51), and on the CANTAB emotion recognition task total percent correct (p = .023, d = .54) displaying particular difficulties in negative affect recognition. The patients exhibited significant impairments in social skills measured with the High Risk Social Challenge (p˂.001, d = 1.05). Aspects of emotion recognition were associated with role functioning and social skill performance. The level of attributional bias was associated with overall functioning, and theory of mind ability was associated with self-reported functioning. Negative symptoms were associated with all measures of functioning (p ≤ .05).ConclusionSignificant impairments in social cognition and social skills were found in UHR patients. The patients' social cognitive function was associated with overall functioning and social skills. Negative symptoms appear to play an important role for functioning. Research is needed to investigate how the relations between social cognition, social skills and functioning develop from the UHR state to the stage of manifest illness. Research into how deficits in social cognition and social skills can be ameliorated in UHR patients is warranted.

Deficits in information processing and cognition are among the most robust findings in schizophrenia patients. Previous efforts to translate group-level deficits into clinically relevant and individualized information have, however, been non-successful, which is possibly explained by biologically different disease subgroups. We applied machine learning algorithms on measures of electrophysiology and cognition to identify potential subgroups of schizophrenia. Next, we explored subgroup differences regarding treatment response. Sixty-six antipsychotic-naive first-episode schizophrenia patients and sixty-five healthy controls underwent extensive electrophysiological and neurocognitive test batteries. Patients were assessed on the Positive and Negative Syndrome Scale (PANSS) before and after 6 weeks of monotherapy with the relatively selective D2 receptor antagonist, amisulpride (280.3±159 mg per day). A reduced principal component space based on 19 electrophysiological variables and 26 cognitive variables was used as input for a Gaussian mixture model to identify subgroups of patients. With support vector machines, we explored the relation between PANSS subscores and the identified subgroups. We identified two statistically distinct subgroups of patients. We found no significant baseline psychopathological differences between these subgroups, but the effect of treatment in the groups was predicted with an accuracy of 74.3% (P=0.003). In conclusion, electrophysiology and cognition data may be used to classify subgroups of schizophrenia patients. The two distinct subgroups, which we identified, were psychopathologically inseparable before treatment, yet their response to dopaminergic blockade was predicted with significant accuracy. This proof of principle encourages further endeavors to apply data-driven, multivariate and multimodal models to facilitate progress from symptom-based psychiatry toward individualized treatment regimens.

One of best validated findings in schizophrenia research is the association between blockade of dopamine D2 receptors and the effects of antipsychotics on positive psychotic symptoms. The aim of the present study was to examine correlations between baseline striatal D2/3 receptor binding potential (BPp) values and treatment outcome in a cohort of antipsychotic-naïve first-episode schizophrenia patients. Additionally, we wished to investigate associations between striatal dopamine D2/3 receptor blockade and alterations of negative symptoms as well as functioning and subjective well-being. Twenty-eight antipsychotic-naïve schizophrenia patients and 26 controls were included in the study. Single-photon emission computed tomography (SPECT) with [123I]iodobenzamide ([123I]-IBZM) was used to examine striatal D2/3 receptor BPp. Patients were examined before and after 6 weeks of treatment with the D2/3 receptor antagonist amisulpride. There was a significant negative correlation between striatal D2/3 receptor BPp at baseline and improvement of positive symptoms in the total group of patients. Comparing patients responding to treatment to nonresponders further showed significantly lower baseline BPp in the responders. At follow-up, the patients demonstrated a negative correlation between the blockade and functioning, whereas no associations between blockade and negative symptoms or subjective well-being were observed. The results show an association between striatal BPp of dopamine D2/3 receptors in antipsychotic-naïve first-episode patients with schizophrenia and treatment response. Patients with a low BPp have a better treatment response than patients with a high BPp. The results further suggest that functioning may decline at high levels of dopamine receptor blockade.