Anhedonia across borders: Transdiagnostic relevance of reward dysfunction for noninvasive brain stimulation endophenotypes.

INTRODUCTION: Anhedonia is a transdiagnostic psychopathological dimension, consisting in the impaired ability to experience pleasure. In order to further our understanding of its neural correlates and to explore its potential relevance as a predictor of treatment response, in this article we systematically reviewed studies involving anhedonia and neuromodulation interventions, across different disorders. METHODS: We included seven studies fulfilling inclusion/exclusion criteria and involving different measures of anticipatory and consummatory anhedonia, as well as different noninvasive brain stimulation interventions (transcranial magnetic stimulation and transcranial direct current stimulation). Studies not exploring hedonic measures or not involving neuromodulation intervention were excluded. RESULTS: All the included studies entailed the use of rTMS protocols in one of the diverse prefrontal targets. The limited amount of studies and the heterogeneity of stimulation protocols did not allow to draw any conclusion with regard to the efficacy of rTMS in the treatment of transnosographic anhedonia. A potential for anhedonia in dissecting possible endophenotypes of different psychopathological conditions preliminarily emerged. CONCLUSIONS: Anhedonia is an underexplored condition in neuromodulation trials. It may represent a valuable transdiagnostic dimension that requires further examination in order to discover new clinical predictors for treatment response.

Transcranial Direct Current Stimulation Reduces Craving in Substance Use Disorders: A Double-blind, Placebo-Controlled Study.

OBJECTIVES: The use of transcranial direct current stimulation (tDCS) in addiction disorders is still on its rise in comparison with pharmacological and psychotherapeutic strategies that still show low level of evidence. In this study, we aimed to evaluate the efficacy of the anodic tDCS for the short-term treatment of substance craving and other psychiatric symptoms. METHODS: In this randomized, double-blind, sham-controlled trial, inclusion criteria included the diagnosis of substance use disorder and/or gambling disorder. The protocol includes 5 consecutive days of active or sham tDCS session. Cathode was placed over the left dorsolateral prefrontal cortex. Hamilton Depression Rating Scale, Hamilton Anxiety Rating Scale, Young Mania Rating Scale, Barratt Impulsiveness Scale, South Oaks Gambling Screen, and visual analog scale (VAS) 1 to 10 for craving were administered at the baseline (T0) and after 5 days of treatment (T1). RESULTS: Thirty-four treatment-seeking subjects were randomized to sham (n = 16) and active stimulation (n = 18) groups. A statistically significant reduction of values at T1 was found in all subjects considering VAS (P < 0.001), Hamilton Depression Rating Scale (P < 0.001), Hamilton Anxiety Rating Scale (P < 0.001), and Barratt Impulsiveness Scale 11 (P = 0.032). A significant reduction for VAS craving in favor of the active stimulation (P = 0.011) was found. CONCLUSIONS: Our findings reveal a statistically significant rapid reduction of craving in the active tDCS group on the right dorsolateral prefrontal cortex with respect to sham group, confirming the scientific literature trend. Large samples, with maintenance tDCS therapy and long-term follow-up, are required to establish the potential of this noninvasive and easily delivered brain stimulation strategy.

Efficacy and Safety of Atypical Antipsychotics in Bipolar Disorder With Comorbid Substance Dependence: A Systematic Review.

OBJECTIVES: Bipolar disorder (BD) patients with a comorbid substance use disorder (SUD) are notoriously difficult to treat. Atypical antipsychotics (AAPs) are widely prescribed in BD, but their efficacy in patients with comorbid SUD is still debated. The aim of the present article is to systematically review the literature findings on the efficacy and safety of AAPs in BD patients with comorbid SUD. METHODS: We searched PubMed to identify original studies focused on the treatment of dual diagnosed BD with AAPs. RESULTS: Ten articles met our inclusion/exclusion criteria, involving a total of 969 subjects, 906 affected by BD and 793 with comorbid SUD: 4 were randomized controlled trials, 4 were open label trials and 2 were observational studies, published between 2002 and 2017. The most commonly abused substances were alcohol and cocaine. The AAPs used to treat patients were quetiapine (n = 337), asenapine (n = 119), olanzapine (n = 80), risperidone (n = 62), and aripiprazole (n = 48). In terms of safety, AAPs were usually well tolerated. Atypical antipsychotics were usually efficacious on acute mood symptoms, whereas their impact on substance-related issues was reported only in those studies without a placebo comparison. CONCLUSIONS: According to our results, even though AAPs are widely used and efficacious in treating the clinical symptoms of BD, there are not enough data to suggest their adjunctive benefit on craving and substance consumption.

Hallucinogen Persisting Perception Disorder: Etiology, Clinical Features, and Therapeutic Perspectives.

Hallucinogen Persisting Perception Disorder (HPPD) is a rare, and therefore, poorly understood condition linked to hallucinogenic drugs consumption. The prevalence of this disorder is low; the condition is more often diagnosed in individuals with a history of previous psychological issues or substance misuse, but it can arise in anyone, even after a single exposure to triggering drugs. The aims of the present study are to review all the original studies about HPPD in order to evaluate the following: (1) the possible suggested etiologies; (2) the possible hallucinogens involved in HPPD induction; (3) the clinical features of both HPPD I and II; (4) the possible psychiatric comorbidities; and (5) the available and potential therapeutic strategies. We searched PubMed to identify original studies about psychedelics and Hallucinogen Persisting Perception Disorder (HPPD). Our research yielded a total of 45 papers, which have been analyzed and tabled to provide readers with the most updated and comprehensive literature review about the clinical features and treatment options for HPPD.

Efficacy of Memantine in Schizophrenic Patients: A Systematic Review.

Several evidences support the hypothesis that glutamatergic dysfunction may be implicated in the pathogenesis of schizophrenia and in the last few years great interest has been focused on the role of the N-methyl-D-aspartate receptor (NMDAR). Glutamate is the main excitatory neurotransmitter in human CNS and it plays a prominent role in synaptic plasticity, learning, and memory and other cognitive functions. Increasing interest in memantine add-on therapy in schizophrenic patients with negative and cognitive symptoms may suggest that memantine could be a new promising treatment in schizophrenia. The aim of this update was to evaluate clinical data about the memantine effectiveness in schizophrenic patients. Our systematic review of the literature highlights that memantine therapy in schizophrenic patients seems to improve mainly negative symptoms while positive symptoms and cognitive symptoms did not improve significantly.

A Case of Resistant Schizophrenia Successfully Treated With Clozapine/Long-acting Injectable Aripiprazole Combination.

BACKGROUND: Treatment-resistant schizophrenia (TRS) is a condition characterized by intense symptom severity and poor response to different antipsychotic agents. The first therapeutic option in TRS is clozapine, but often high/medium doses are not tolerated. Adding an oral antipsychotic to low doses of clozapine is a promising strategy in the management of TRS. On the contrary, there are few data on combined clozapine/long-acting injectable (LAI) medications, and none on clozapine/LAI-aripiprazole. CASE: A 21-year-old male schizophrenic patient, resistant to several oral and LAI medications, partially improved after clozapine 300 mg/d treatment. Unfortunately, he also reported excessive sedation and an episode of myoclonus, so clozapine was reduced to 150 mg/d, but no additional benefits were observed. Subsequently, LAI-aripiprazole (first 200 mg/mo, then 400 mg/mo) was added, and the patient's conditions dramatically improved over time. After 1 year of observation, symptoms reduction was 50% or greater, without significant adverse events. CONCLUSIONS: Clozapine use in TRS is often reduced or delayed due to the fear of serious adverse effects. Adding LAI-aripiprazole to low doses of clozapine may be a useful therapeutic option to obtain a good efficacy/tolerability balance.

Sustained attention in psychosis: Neuroimaging findings.

To provide a systematic review of scientific literature on functional magnetic resonance imaging (fMRI) studies on sustained attention in psychosis. We searched PubMed to identify fMRI studies pertaining sustained attention in both affective and non-affective psychosis. Only studies conducted on adult patients using a sustained attention task during fMRI scanning were included in the final review. The search was conducted on September 10(th), 2013. 15 fMRI studies met our inclusion criteria: 12 studies were focused on Schizophrenia and 3 on Bipolar Disorder Type I (BDI). Only half of the Schizophrenia studies and two of the BDI studies reported behavioral abnormalities, but all of them evidenced significant functional differences in brain regions related to the sustained attention system. Altered functioning of the insula was found in both Schizophrenia and BDI, and therefore proposed as a candidate trait marker for psychosis in general. On the other hand, other brain regions were differently impaired in affective and non-affective psychosis: alterations of cingulate cortex and thalamus seemed to be more common in Schizophrenia and amygdala dysfunctions in BDI. Neural correlates of sustained attention seem to be of great interest in the study of psychosis, highlighting differences and similarities between Schizophrenia and BDI.