Minor tranquillizers for short-term treatment of newly onset symptoms of anxiety and distress: a systematic review with network meta-analysis of randomized trials.

Unspecific symptoms of anxiety and distress are frequently encountered in patients in both general practice and acute psychiatric services. Minor tranquillizers may be a treatment option when non-pharmacological interventions are insufficient or unavailable. We conducted a systematic review with network meta-analysis of the evidence for short-term (1-4 weeks) pharmacological treatment of newly onset symptoms of anxiety and distress. We searched the PsycInfo, MEDLINE, EMBASE and Cochrane Library databases and extracted data following a predefined hierarchy of outcomes. We assessed risk of bias using the Cochrane Risk of Bias tool and the certainty of the evidence using the Grading of Recommendations Assessment, Development and Evaluation framework (GRADE). We included 34 randomized trials comprising a total of 7044 patients with adjustment disorders or anxiety spectrum disorders. The network meta-analysis showed that regarding the critical outcome symptoms of anxiety within 1-4 weeks benzodiazepines (SMD - 0.58, 95% CI - 0.77 to - 0.40), quetiapine (SMD - 0.51, 95% CI - 0.90 to - 0.13) and pregabalin (SMD - 0.58, 95% CI - 0.87 to - 0.28) all performed better than placebo with no statistically significant difference between the drugs. Data on other important outcomes were inconsistently reported. Adverse effects varied, but overall, it was uncertain whether adverse effects differed between interventions. The evidence regarding the risk of dependence was uncertain, but dependence may be a concern in susceptible individuals even with short-term treatment. Overall, the certainty of the evidence according to GRADE was rated as low to very low across outcomes. Despite the limitations in the evidence, the results of this review can inform treatment guidelines, supporting clinicians in the choice of minor tranquillizer in this prevalent and help-seeking, clinically heterogeneous population.

The short-term and long-term adverse effects of melatonin treatment in children and adolescents: a systematic review and GRADE assessment.

Background: Currently, melatonin is used to treat children and adolescents with insomnia without knowing the full extent of the short-term and long-term consequences. Our aim was to provide clinicians and guideline panels with a systematic assessment of serious-and non-serious adverse events seen in continuation of melatonin treatment and the impact on pubertal development and bone health following long-term administration in children and adolescents with chronic insomnia. Methods: We searched PubMed, Embase, Cinahl and PsycINFO via Ovid, up to March 17, 2023, for studies on melatonin treatment among children and adolescents (aged 5-20 years) with chronic insomnia. The language was restricted to English, Danish, Norwegian, and Swedish. Outcomes were non-serious adverse events and serious adverse events assessed 2-4 weeks after initiating treatment and pubertal development and bone health, with no restriction on definition or time of measurement. Observational studies were included for the assessment of long-term outcomes, and serious and non-serious adverse events were assessed via randomised studies. The certainty of the evidence was assessed using Grades of Recommendation, Assessment, Development and Evaluation (GRADE). The protocol is registered with the Danish Health Authority. Findings: We identified 22 randomised studies with 1350 patients reporting on serious-and non-serious adverse events and four observational studies with a total of 105 patients reporting on pubertal development. Melatonin was not associated with serious adverse events, yet the number of patients experiencing non-serious adverse events was increased (Relative risk 1.56, 95% CI 1.01-2.43, 17 studies, I2 = 47%). Three studies reported little or no influence on pubertal development following 2-4 years of treatment, whereas one study registered a potential delay following longer treatment durations (>7 years). These findings need further evaluation due to several methodological limitations. Interpretation: Children who use melatonin are likely to experience non-serious adverse events, yet the actual extent to which melatonin leads to non-serious adverse events and the long-term consequences remain uncertain. This major gap of knowledge on safety calls for caution against complacent use of melatonin in children and adolescents with chronic insomnia and for more research to inform clinicians and guideline panels on this key issue. Funding: The Danish Health Authority. The Parker Institute, Bispebjerg and Frederiksberg Hospital, supported by the Oak Foundation.

Use of melatonin for children and adolescents with chronic insomnia attributable to disorders beyond indication: a systematic review, meta-analysis and clinical recommendation.

Background: Melatonin has become a widely used sleeping aid for young individuals currently not included in existing guidelines. The aim was to develop a recommendation on the use of melatonin in children and adolescents aged 2-20 years, with chronic insomnia due to disorders beyond indication. Methods: We performed a systematic search for guidelines, systematic reviews, and randomised trials (RCTs) in Medline, Embase, Cochrane Library, PsycInfo, Cinahl, Guidelines International Network, Trip Database, Canadian Agency for Drugs and Technologies in Health, American Academy of Sleep Medicine, European Sleep Research Society and Scandinavian Health Authorities databases. A separate search for adverse events was also performed. The latest search for guidelines, systematic reviews, and adverse events was performed on March 17, 2023. The latest search for RCTs was performed on to February 6, 2023. The language was restricted to English, Danish, Norwegian, and Swedish. Eligible participants were children and adolescents (2-20 years of age) with chronic insomnia due to underlying disorders, in whom sleep hygiene practices have been inadequate and melatonin was tested. Studies exclusively on autism spectrum disorders or attention deficit hyperactive disorder were excluded. There were no restrictions on dosage, duration of treatment, time of consumption or release formula. Primary outcomes were quality of sleep, daytime functioning and serious adverse events, assessed at 2-4 weeks post-treatment. Secondary outcomes included total sleep time, sleep latency, awakenings, drowsiness, quality of life, non-serious adverse events, and all-cause dropouts (assessed at 2-4 weeks post-treatment), plus quality of sleep and daytime functioning (assessed at 3-6 months post-treatment). Pooled estimates were calculated using inverse variance random effects model. Statistical heterogeneity was calculated using I2 statistics. Risk of bias was assessed using Cochrane risk of bias tool. Publication bias was assessed using funnel plots. A multidisciplinary guideline panel constructed the recommendation using Grades of Recommendation, Assessment, Development and Evaluation (GRADE). The certainty of evidence was considered either high, moderate, low or very low depending on the extent of risk of bias, inconsistency, imprecision, indirectness, or publication bias. The evidence-to-decision framework was used to discuss the feasibility and acceptance of the constructed recommendation and its impact on resources and equity. The protocol is registered with the Danish Health Authority. Findings: We identified 13 RCTs, including 403 patients with a wide range of conditions. Melatonin reduced sleep latency by 14.88 min (95% CI 23.42-6.34, 9 studies, I2 = 60%) and increased total sleep time by 18.97 min (95% CI 0.37-37.57, 10 studies, I2 = 57%). The funnel plot for total sleep time showed no apparent indication of publication bias. No other clinical benefits were found. The number of patients experiencing adverse events was not statistically increased however, safety data was scarce. Certainty of evidence was low. Interpretation: Low certainty evidence supports a moderate effect of melatonin in treating sleep continuity parameters in children and adolescents with chronic insomnia due to primarily medical disorders beyond indication. The off-label use of melatonin for these patients should never be the first choice of treatment, but may be considered by medical specialists with knowledge of the underlying disorder and if non-pharmacological interventions are inadequate. If treatment with melatonin is initiated, adequate follow-up to evaluate treatment effect and adverse events is essential. Funding: The Danish Health Authority. The Parker Institute, Bispebjerg and Frederiksberg Hospital, supported by the Oak Foundation.

Use of melatonin in children and adolescents with idiopathic chronic insomnia: a systematic review, meta-analysis, and clinical recommendation.

Background: Melatonin prescriptions for children and adolescents have increased substantially during the last decade. Existing clinical recommendations focus on melatonin as a treatment for insomnia related to neurodevelopmental disorders. To help guide clinical decision-making, we aimed to construct a recommendation on the use of melatonin in children and adolescents aged 5-20 years with idiopathic chronic insomnia. Methods: A systematic search for guidelines, systematic reviews and randomised controlled trials (RCT) were performed in Medline, Embase, Cochrane Library, PsycInfo, Cinahl, Guidelines International Network, Trip Database, Canadian Agency for Drugs and Technologies in Health, American Academy of Sleep Medicine, European Sleep Research Society and Scandinavian Health Authorities databases. A search for adverse events in otherwise healthy children and adolescents was also performed. The latest search for guidelines, systematic reviews, and adverse events was performed on March 18, 2023. The latest search for RCTs was performed on to February 6, 2023. The language was restricted to English, Danish, Norwegian, and Swedish. Eligible participants were children and adolescents (5-20 years of age) with idiopathic chronic insomnia, in whom sleep hygiene practices have been inadequate and melatonin was tested. There were no restrictions on dosage, duration of treatment, time of consumption, or release formula. Primary outcomes were quality of sleep, daytime functioning and serious adverse events. Secondary outcomes included total sleep time, sleep latency, awakenings, drowsiness, quality of life, all-cause dropouts, and non-serious adverse events. Outcomes were assessed at different time points to assess short-term and long-term effects. Meta-analysis was performed using inverse variance random-effects model and risk of bias was assessed using Cochrane risk of bias tool. If possible, funnel plots would be constructed to investigate publication bias. Heterogeneity was calculated via I2 statistics. A multidisciplinary guideline panel formulated the recommendation according to Grading of Recommendations Assessment, Development and Evaluation (GRADE). The certainty of evidence was considered either high, moderate, low or very low depending on the extent of risk of bias, inconsistency, imprecision, indirectness, or publication bias. The evidence-to-decision framework was subsequently used to discuss the feasibility and acceptance of the constructed recommendation alongside the impact on resources and equity. The protocol is registered with the Danish Health Authority. Findings: We included eight RCTs with 419 children and adolescents with idiopathic chronic insomnia. Melatonin led to a moderate increase in total sleep time by 30.33 min (95% confidence interval (CI) 18.96-41.70, 4 studies, I2 = 0%) and a moderate reduction in sleep latency by 18.03 min (95% CI -26.61 to -9.44, 3 studies, I2 = 0%), both as assessed by sleep diary. No other beneficial effects were found. None of the studies provided information on serious adverse events, yet the number of participants experiencing non-serious adverse events was increased (Relative risk 3.44, 95% CI 1.25-9.42, 4 studies, I2 = 0%). Funnel plots were not constructed due to the low number of studies. The certainty of evidence was very low on the quality of sleep and low for daytime functioning. Interpretation: Evidence of very low certainty shows that benefits are limited and unwanted events are likely when melatonin is used to treat otherwise healthy children and adolescents with chronic insomnia. Melatonin should never be the first choice of treatment for this particular population, yet carefully monitored short-term use may be considered if sleep hygiene practices and non-pharmacological interventions have proven inadequate, and only if daytime function is compromised. Funding: The Danish Health Authority and the Parker Institute, Bispebjerg and Frederiksberg Hospital supported by the Oak Foundation.

The Effects of Exercise during Pregnancy on Gestational Diabetes Mellitus, Preeclampsia, and Spontaneous Abortion among Healthy Women-A Systematic Review and Meta-Analysis.

The aim was to compare the effects of different exercise modalities (aerobic, resistance, aerobic and resistance combined, or mind-body exercise) on gestational diabetes mellitus (GDM), preeclampsia, spontaneous abortion, withdrawal from the study, and adverse events in healthy pregnant women. A systematic search was conducted in February 2022 using MEDLINE, EMBASE, Cochrane library, and SPORT Discus to identify eligible randomized trials. The meta-analysis of 18 studies that examined exercise compared to no exercise showed a reduced risk of GDM (RR: 0.66 (95% CI: 0.50 to 0.86)). No subgroup differences were found regarding modality, intensity, or supervision. Exercise did not reduce the risk of preeclampsia (nine studies, RR: 0.65 (95% CI: 0.42 to 1.03)); however, in subgroup analyses, mind-body exercise and low-intensity exercise seemed to be effective in reduction of preeclampsia. There was no effect of exercise on withdrawal or adverse events found. No studies reported on spontaneous abortion, therefore, exercise during pregnancy is beneficial and safe. In the prevention of GDM, any modality and intensity seem equally effective. Subgroup analyses support an association between mind-body exercise and physical activity with low intensity and reduced risk of preeclampsia, but more high-quality randomized studies are needed. PROSPERO: CRD42022307053.

Supplement Treatment with NAC and Omega-3 Polyunsaturated Fatty Acids during Pregnancy Partially Prevents Schizophrenia-Related Outcomes in the Poly I:C Rat Model.

BACKGROUND: Heightened levels of inflammation and oxidative stress are thought to be involved in the pathophysiology of schizophrenia. We aimed to assess whether intake of anti-inflammatory and anti-oxidant drugs during pregnancy prevents later schizophrenia-related outcomes in a neurodevelopmental rat model of this disorder. METHODS: Pregnant Wistar rats were injected with polyriboinosinic-polyribocytidilic acid (Poly I:C) or saline and subsequently treated with either N-acetyl cysteine (NAC) or omega-3 polyunsaturated fatty acids (PUFAs) until delivery. Controls rats received no treatment. In the offspring, neuroinflammation and anti-oxidant enzyme activity were assessed on postnatal day (PND) 21, 33, 48, and 90. Behavioral testing was performed at PND 90, followed by post-mortem neurochemical assessment and ex vivo MRI. RESULTS: The supplement treatment led to a quicker restoration of the wellbeing of dams. In the adolescent Poly I:C offspring, the supplement treatment prevented an increase in microglial activity and partially prevented a deregulation in the anti-oxidant defense system. In the adult Poly I:C offspring, supplement treatment partially prevented dopamine deficits, which was paralleled by some changes in behavior. Exposure to omega-3 PUFAs prevented the enlargement of lateral ventricles. CONCLUSION: Intake of over-the-counter supplements may assist in especially targeting the inflammatory response related to schizophrenia pathophysiology, aiding in diminishing later disease severity in the offspring.

Adolescent raloxifene treatment in females prevents cognitive deficits in a neurodevelopmental rodent model of schizophrenia.

The existence of sex differences in schizophrenia is a well documented phenomenon which led to the hypothesis that female sex hormones are neuroprotective and hence responsible for the more favorable disease characteristics seen in women. The current study sought to investigate the effects of estrogen-like agents administered during early adolescence on behavioral outcomes in adulthood using the neurodevelopmental maternal immune activation (MIA) rodent model of schizophrenia. Female MIA offspring were administered during the asymptomatic period of adolescence with either 17ß-estradiol, raloxifene or saline and were tested in late adolescence and adulthood for schizophrenia-related behavioral performance. We report here that whereas adult female MIA offspring exhibited cognitive deficits in the form of retarded spatial learning, the administration of raloxifene during adolescence was sufficient in preventing these deficits and resulted in intact performance in the MIA group.

Former Training Relieves the Later Development of Behavioral Inflexibility in an Animal Model Overexpressing the Dopamine Transporter.

A range of dopamine-dominating neuropsychiatric disorders present with cognitive deficits. In accordance, the dopamine transporter overexpressing rat model (DAT-tg rat) displays cognitive deficits by means of behavioral inflexibility and learning disabilities. It remains to be investigated when cognitive deficits emerge, due to the inherent DA irregularities, during the life course of the DAT-tg rat and what may relieve symptoms. The Morris water maze (MWM) was used to assess cognitive abilities in three cohorts of DAT-tg rats. In the first cohort, the development of cognitive deficits was assessed by repeatedly testing animals in the MWM at postnatal day (PND) 35, 60, and 90. In the second and third cohort, pharmacological interventions and transcranial direct current stimulation (tDCS) were tested in adult animals to understand what drives, and thus relieves, the deficits. Minor differences were observed between DAT-tg rats and control rats at PND 35 and 60, whereas cognitive deficits fully emerged at PND 90. A high dosage of methylphenidate diminished both behavioral inflexibility and improved learning abilities in adult rats. Interestingly, rats subjected early in life to the MWM also displayed improved behavioral flexibility as compared to rats naïve to the paradigm. Cognitive deficits gradually develop over time and fully emerge in adulthood. Pharmacological modulation of the ubiquitous DAT overexpression overall improves deficits in adult rats, whereas early training decreases later development of behavioral inflexibility. Thus, former training may constitute a preventive avenue that alters some aspects of cognitive deficits resulting from inherent DA abnormalities.

Psychotherapies for borderline personality disorder: a focused systematic review and meta-analysis.

BACKGROUND: A recently updated Cochrane review supports the efficacy of psychotherapy for borderline personality disorder (BPD). AIMS: To evaluate the effects of standalone and add-on psychotherapeutic treatments more concisely. METHOD: We applied the same methods as the 2020 Cochrane review, but focused on adult samples and comparisons of active treatments and unspecific control conditions. Standalone treatments (i.e. necessarily including individual psychotherapy as either the sole or one of several treatment components) and add-on interventions (i.e. complementing any ongoing individual BPD treatment) were analysed separately. Primary outcomes were BPD severity, self-harm, suicide-related outcomes and psychosocial functioning. Secondary outcomes were remaining BPD diagnostic criteria, depression and attrition. RESULTS: Thirty-one randomised controlled trials totalling 1870 participants were identified. Among standalone treatments, statistically significant effects of low overall certainty were observed for dialectical behaviour therapy (self-harm: standardised mean difference (SMD) -0.54, P = 0.006; psychosocial functioning: SMD -0.51, P = 0.01) and mentalisation-based treatment (self-harm: risk ratio 0.51, P < 0.0007; suicide-related outcomes: risk ratio 0.10, P < 0.0001). For adjunctive interventions, moderate-quality evidence of beneficial effects was observed for DBT skills training (BPD severity: SMD -0.66, P = 0.002; psychosocial functioning: SMD -0.45, P = 0.002), and statistically significant low-certainty evidence was observed for the emotion regulation group (BPD severity: mean difference -8.49, P < 0.00001), manual-assisted cognitive therapy (self-harm: mean difference -3.03, P = 0.03; suicide-related outcomes: SMD -0.96, P = 0.005) and the systems training for emotional predictability and problem-solving (BPD severity: SMD -0.48, P = 0.002). CONCLUSIONS: There is reasonable evidence to conclude that psychotherapeutic interventions are helpful for individuals with BPD. Replication studies are needed to enhance the certainty of findings.

Using cortical non-invasive neuromodulation as a potential preventive treatment in schizophrenia - A review.

BACKGROUND: Evidence suggests that schizophrenia constitutes a neurodevelopmental disorder, characterized by a gradual emergence of behavioral and neurobiological abnormalities over time. Therefore, applying early interventions to prevent later manifestation of symptoms is appealing. OBJECTIVE: This review focuses on the use of cortical neuromodulation in schizophrenia and its potential as a preventive treatment approach. We present clinical and preclinical findings investigating the use of neuromodulation in schizophrenia, including the current research focusing on cortical non-invasive stimulation and its possibility as a future preventive treatment. METHODS: We performed a search in Medline (PubMed) in September 2020 using a combination of relevant medical subject headings (MeSH) and text words. The search included human and preclinical trials as well as existing systematic reviews and meta-analysis. There were no restrictions on language or the date of publication. RESULTS: Neurodevelopmental animal models may be used to investigate how the disease progresses and thus which brain areas ideally should be targeted at a given time point. Here, abnormalities of the prefrontal cortex have been often identified as an early and persistent impairment in schizophrenia. Currently there is insufficient evidence to either support or refute the use of neuromodulation to the cortex in adult patients with already manifested symptoms. However, preclinical results show that early non-invasive neuromodulation to the prefrontal cortex of adolescent animals, sufficiently prevents later psychosis-relevant abnormalities in adulthood. This points to the promising potential of cortical non-invasive neuromodulation as a preventive treatment when applied early in the course of the disease. CONCLUSION: Preclinical translational-oriented findings indicate, that neuromodulation to cortical areas offers the possibility of targeting early neuropathology and through this diminish the progression of a later schizophrenic profile. Further studies are needed to investigate whether such early cortical stimulation may serve as a future preventive treatment in schizophrenia.

Prevention of schizophrenia deficits via non-invasive adolescent frontal cortex stimulation in rats.

Schizophrenia is a severe neurodevelopmental psychiatric affliction manifested behaviorally at late adolescence/early adulthood. Current treatments comprise antipsychotics which act solely symptomatic, are limited in their effectiveness and often associated with side-effects. We here report that application of non-invasive transcranial direct current stimulation (tDCS) during adolescence, prior to schizophrenia-relevant behavioral manifestation, prevents the development of positive symptoms and related neurobiological alterations in the maternal immune stimulation (MIS) model of schizophrenia.

Current state of evidence for endolymphatic sac surgery in Menière's disease: a systematic review.

Background: Endolymphatic sac surgery is an invasive procedure recommended to patients with Menière's disease. Aims/Objectives: To provide an overview and quality assessment of the existing evidence and to provide an updated assessment of the utility of endolymphatic sac surgery in Menière's disease. Material and Methods: We performed a systematic literature search for systematic reviews and randomized controlled trials (RCTs). The AMSTAR tool was used to assess the quality of systematic reviews and the Cochrane risk of bias tool for RCTs. The overall certainty of effects for the individual outcomes was evaluated using the GRADE approach. Results: One systematic review of high quality matched the inclusion criteria, and included three RCTs. An updated literature search from the last search date of the included review provided no further relevant RCTs. The identified RCTs individually reported a positive effect of both the placebo and active treatment groups following surgery, strongly indicative of a placebo effect. The overall certainty of the effect was very low. Conclusions and significance: There is still a lack of high-quality research suggesting that endolymphatic sac surgery provides a significant amount of symptomatic relief for Menière's patients.

Recurrent stress across life may improve cognitive performance in individual rats, suggesting the induction of resilience.

Depressive symptoms are often accompanied by cognitive impairments and recurrent depressive episodes are discussed as a potential risk for dementia. Especially, stressful life events are considered a potent risk factor for depression. Here, we induced recurrent stress-induced depressive episodes over the life span of rats, followed by cognitive assessment in the symptom-free period. Rats exposed to stress-induced depressive episodes learned faster than control rats. A high degree of stress-induced depressive-like behavior early in the paradigm was a predictor of improved cognitive performance, suggesting induction of resilience. Subsequently, exposure to lorazepam prior to stress-induced depressive episodes and cognitive testing in a nonaversive environment prevented the positive effect. This indicates a beneficial effect of the stress-associated situation, with the existence of individual coping abilities. Altogether, stress may in some have a beneficial effect, yet for those individuals unable to tackle these aversive events, consecutive unpleasant episodes may lead to worse cognitive performance later in life.

Intratympanic Steroid for Menière's Disease: A Systematic Review.

OBJECTIVES: To investigate the beneficial effects and safety of intratympanic steroid installation compared with placebo in patients with Menière's disease. METHODS: We performed a systematic literature search in MEDLINE and EMBASE for existing systematic reviews and individual randomized controlled trials (RCTs). Studies were included if they investigated the usage intratympanic steroids in patients aged 18 and above, with definite or probable Menière's disease. The quality of the identified existing reviews was assessed using the AMSTAR tool. The risk of bias in RCTs was assessed using the Cochrane Risk of Bias Tool and overall quality of the individual outcomes was evaluated using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) method. RESULTS: The literature search provided four systematic reviews, from which one yielded a sufficient AMSTAR evaluation and subsequently provided three RCTs relevant for inclusion. Due to the lack of sufficient reporting of the data, quantitative synthesis was not applicable. In the qualitative synthesis for the primary outcome, the results from the RCTs showed that there was a slight indication of steroid treatment reducing the frequency of vertiginous attacks. No serious adverse events were reported. Based on the GRADE approach the quality for both findings is very low. No studies reported on the secondary outcomes. CONCLUSION: The effect of intratympanic steroid treatment in Menière's disease is questionable. There is a great need for further research to sufficiently assess whether steroid treatment may be considered as a safe and effective treatment for patients with Menière's disease.

Positive pressure device treatment for Menière's disease: an overview of the current evidence and a meta-analysis.

OBJECTIVE: The objective was to critically assess the current evidence investigating the efficacy of using a positive pressure device in patients with definite or probable Menière's disease. METHODS: We performed a systematic literature search in MEDLINE, EMBASE and PsycINFO up to February 2018. We included both systematic reviews and primary literature [randomized controlled trials (RCTs)] investigating positive pressure treatment, in patients (≥ 18 years of age), with Menière's disease. We assessed the internal validity of systematic reviews using the AMSTAR tool and risk of bias of primary studies using the Cochrane Risk of bias tool. We performed a meta-analysis for each outcome based on the identified studies. The overall certainty of evidence for the outcomes was assessed using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE). RESULTS: The search for systematic reviews identified four relevant reviews. These all included the same four RCTs. An updated search identified one additional RCT. In total, five RCTs were included in the data synthesis. Our data synthesis showed no effect of positive pressure treatment on primary nor secondary outcomes. No serious adverse events were reported. The overall certainty of evidence ranged from very low to low, due to the serious risk of bias and imprecision. CONCLUSION: The current available evidence does not support positive pressure device treatment in patients with Menière's disease. However, the limitations of the current literature hinder the possibility of any solid conclusion. There remains a need for randomized controlled trials of high quality to fully access the utility of this treatment.

Learning deficits in rats overexpressing the dopamine transporter.

With its capacity to modulate motor control and motivational as well as cognitive functions dopamine is implicated in numerous neuropsychiatric diseases. The present study investigated whether an imbalance in dopamine homeostasis as evident in the dopamine overexpressing rat model (DAT-tg), results in learning and memory deficits associated with changes in adult hippocampal neurogenesis. Adult DAT-tg and control rats were subjected to the Morris water maze, the radial arm maze and a discrimination reversal paradigm and newly generated neurons in hippocampal circuitry were investigated post mortem. DAT-tg rats were found to exhibit a striking inability to acquire information and deploy spatial search strategies. At the same time, reduced integration of adult-born neurons in hippocampal circuitry was observed, which together with changes in striatal dopamine signalling might explain behavioural deficits.

Non-invasive modulation reduces repetitive behavior in a rat model through the sensorimotor cortico-striatal circuit.

Involuntary movements as seen in repetitive disorders such as Tourette Syndrome (TS) results from cortical hyperexcitability that arise due to striato-thalamo-cortical circuit (STC) imbalance. Transcranial direct current stimulation (tDCS) is a stimulation procedure that changes cortical excitability, yet its relevance in repetitive disorders such as TS remains largely unexplored. Here, we employed the dopamine transporter-overexpressing (DAT-tg) rat model to investigate behavioral and neurobiological effects of frontal tDCS. The outcome of tDCS was pathology dependent, as anodal tDCS decreased repetitive behavior in the DAT-tg rats yet increased it in wild-type (wt) rats. Extensive deep brain stimulation (DBS) application and computational modeling assigned the response in DAT-tg rats to the sensorimotor pathway. Neurobiological assessment revealed cortical activity changes and increase in striatal inhibitory properties in the DAT-tg rats. Our findings show that tDCS reduces repetitive behavior in the DAT-tg rat through modulation of the sensorimotor STC circuit. This sets the stage for further investigating the usage of tDCS in repetitive disorders such as TS.

Face identity is encoded in the duration of N170 adaptation.

Previous studies assessing the involvement of the face-sensitive N170 component of the event-related potential (ERP) in the processing of face identity have shown controversial results when assessing N170 amplitude in repetition suppression (RS) designs. On the other hand, N170 adaptation is robustly associated with the inter-stimulus interval (ISI) between immediate face repetitions. Interestingly, interactions of face identity and ISI could provide valuable information on early encoding of face identity, but have not been investigated so far. We employed a repetition suppression paradigm using identical and non-identical repetitions as well as parametrically varied ISIs between 500 msec and 2,000 msec in 27 healthy subjects to investigate N170 adaptation effects. Both face identity and varying ISIs significantly influenced N170 adaptation effects, albeit with small effects sizes. Most importantly, however, face identity and ISIs strongly interacted with rapid N170 amplitude recovery in non-identical trials, but sustained N170 adaptation in identical trials. We excluded low-level sensory contributions to the N170 adaptation effect by analyzing the P1 component and by running an additional experiment employing different stimulus sizes. This specific result strongly argues in favor of neuronal sensitivity to face identity, which is primarily mirrored in the N170 temporal decay function that essentially differentiates identical and non-identical face trials. In general, taking advantage of the temporal dimension of adaptation processes, i.e., their decay over time, provides additional dissections of neuronal function into feature-specific selectivity versus non-selectivity.

Obsessive-compulsive disorder: Insights from animal models.

Research with animal models of obsessive-compulsive disorder (OCD) shows the following: (1) Optogenetic studies in mice provide evidence for a plausible cause-effect relation between increased activity in cortico-basal ganglia-thalamo-cortical (CBGTC) circuits and OCD by demonstrating the induction of compulsive behavior with the experimental manipulation of the CBGTC circuit. (2) Parallel use of several animal models is a fruitful paradigm to examine the mechanisms of treatment effects of deep brain stimulation in distinct OCD endophenotypes. (3) Features of spontaneous behavior in deer mice constitute a rich platform to investigate the neurobiology of OCD, social ramifications of a compulsive phenotype, and test novel drugs. (4) Studies in animal models for psychiatric disorders comorbid with OCD suggest comorbidity may involve shared neural circuits controlling expression of compulsive behavior. (5) Analysis of compulsive behavior into its constitutive components provides evidence from an animal model for a motivational perspective on OCD. (6) Methods of behavioral analysis in an animal model translate to dissection of compulsive rituals in OCD patients, leading to diagnostic tests.

Deep brain stimulation during early adolescence prevents microglial alterations in a model of maternal immune activation.

In recent years schizophrenia has been recognized as a neurodevelopmental disorder likely involving a perinatal insult progressively affecting brain development. The poly I:C maternal immune activation (MIA) rodent model is considered as a neurodevelopmental model of schizophrenia. Using this model we and others demonstrated the association between neuroinflammation in the form of altered microglia and a schizophrenia-like endophenotype. Therapeutic intervention using the anti-inflammatory drug minocycline affected altered microglia activation and was successful in the adult offspring. However, less is known about the effect of preventive therapeutic strategies on microglia properties. Previously we found that deep brain stimulation of the medial prefrontal cortex applied pre-symptomatically to adolescence MIA rats prevented the manifestation of behavioral and structural deficits in adult rats. We here studied the effects of deep brain stimulation during adolescence on microglia properties in adulthood. We found that in the hippocampus and nucleus accumbens, but not in the medial prefrontal cortex, microglial density and soma size were increased in MIA rats. Pro-inflammatory cytokine mRNA was unchanged in all brain areas before and after implantation and stimulation. Stimulation of either the medial prefrontal cortex or the nucleus accumbens normalized microglia density and soma size in main projection areas including the hippocampus and in the area around the electrode implantation. We conclude that in parallel to an alleviation of the symptoms in the rat MIA model, deep brain stimulation has the potential to prevent the neuroinflammatory component in this disease.