Different patterns of local field potentials from limbic DBS targets in patients with major depressive and obsessive compulsive disorder.

The role of distinct limbic areas in emotion regulation has been largely inferred from neuroimaging studies. Recently, the opportunity for intracranial recordings from limbic areas has arisen in patients undergoing deep brain stimulation (DBS) for neuropsychiatric disorders including major depressive disorder (MDD) and obsessive compulsive disorder (OCD). Here we test the hypothesis that distinct temporal patterns of local field potential (LFP) activity in the human limbic system reflect disease state and symptom severity in MDD and OCD patients. To this end, we recorded LFPs via implanted DBS electrodes from the bed nucleus of stria terminalis (BNST area) in 12 patients (5 OCD, 7 MDD) and from the subgenual cingulate cortex in 7 MDD patients (CG25 area). We found a distinct pattern of oscillatory activity with significantly higher α-power in MDD compared with OCD in the BNST area (broad α-band 8-14 Hz; P<0.01) and a similar level of α-activity in the CG25 area as in the BNST area in MDD patients. The mean α-power correlated with severity of depressive symptoms as assessed by the Beck depression inventory in MDD (n=14, r=0.55, P=0.042) but not with severity of obsessive compulsive symptoms in OCD. Here we show larger α-band activity in MDD patients compared with OCD recorded from intracranial DBS targets. Our results suggest that α-activity in the limbic system may be a signature of symptom severity in MDD and may serve as a potential state biomarker for closed loop DBS in MDD.

Synergistic interactions among growing stressors increase risk to an Arctic ecosystem.

Oceans provide critical ecosystem services, but are subject to a growing number of external pressures, including overfishing, pollution, habitat destruction, and climate change. Current models typically treat stressors on species and ecosystems independently, though in reality, stressors often interact in ways that are not well understood. Here, we use a network interaction model (OSIRIS) to explicitly study stressor interactions in the Chukchi Sea (Arctic Ocean) due to its extensive climate-driven loss of sea ice and accelerated growth of other stressors, including shipping and oil exploration. The model includes numerous trophic levels ranging from phytoplankton to polar bears. We find that climate-related stressors have a larger impact on animal populations than do acute stressors like increased shipping and subsistence harvesting. In particular, organisms with a strong temperature-growth rate relationship show the greatest changes in biomass as interaction strength increased, but also exhibit the greatest variability. Neglecting interactions between stressors vastly underestimates the risk of population crashes. Our results indicate that models must account for stressor interactions to enable responsible management and decision-making.

[Procedural learning and Parkinson disease: implication of striato-frontal loops]. / Apprentissage procédural et maladie de Parkinson: implication des boucles striato-frontales.

OBJECTIVE: To investigate procedural learning in non demented patients with idiopathic Parkinson's disease (PD). BACKGROUND: Experimental evidence implicate the basal ganglia in procedural learning. Selective impairment has more recently been described in patients with frontal lesions. METHODS: The performance of 20 demented patients and 15 matched normal controls was studied in the serial reaction time task (SRTT). Performance on procedural task was further compared with that of 9 normal controls and with patients' performance on tests assessing explicit memory, executive functions and global efficiency. RESULTS: The group of patients with PD showed impaired procedural learning. The difference of response time between the repeated and the non-repeated blocks was smaller in PD when compared to controls. Subsequent analyses separated PD patients into two subgroups according to their performance on SRTT, measured by the rebound effect. PD patients whose learning was normal differed from PD patients whose learning was impaired on performance in tests sensitive to frontal lobe dysfunction. CONCLUSION: These results confirm the implication of the striatum in procedural learning and suggest that performance on cognitive procedural learning depends on the striato-frontal circuits.

[Psychopharmacologic treatment of personality disorders]. / Psychopharmakologische Behandlung von und bei Persönlichkeitsstörungen.

There is only a paucity of studies concerning the pharmacological treatment of personality disorders per se. On the other hand the clinical use of medication in these conditions is quite high, although there is no effective psychopharmacological treatment of distinct personality disorders. The psychopharmacological treatment of patients suffering from a personality disorder focuses on distinct symptoms and its comorbidity. Some symptoms could also be associated with other disorders like depression or psychosis, which often makes an exact differentiation of these disorders and a personality disorder difficult. Since symptoms of personality disorders are ego-syntonic, chronic and very often dependent on psychosocial factors, it is unlikely that a solely psychopharmacological treatment will be successful in most patients with a personality disorder. However, severe syndromes like depressive, impulsive, aggressive, dissociative, anxious or psychotic features may render a pharmacotherapy necessary. For the treatment of depressive syndromes or impulsivity a medical therapy with serotonin reuptake inhibitors, for the treatment of psychotic syndromes a medication with atypical antipsychotics is recommended. Impulsive or aggressive behaviour could be treated with mood stabilizers as well. Furthermore, there are indications for the use of alpha2-agonists, micro-opiate-antagonists and omega-3 fatty acid. The general use of benzodiazepines should be avoided as well as polypragmasy. Advantages versus potential damage of a high dose pharmacotherapy should be carefully weighed against each other. This article gives an overview over the today's most common psychopharmacological treatment possibilities in patients with a personality disorder.

Preliminary evidence of improvement of depressive symptoms but not impulsivity in cluster B personality disorder patients treated with quetiapine: an open label trial.

INTRODUCTION: Atypical antipsychotics might become a new treatment option for patients with an impaired impulse regulation as seen in cluster B personality disorders (PD). The aim of the present study is to investigate the efficacy and tolerability of quetiapine in patients with cluster B PD. METHODS: Fifteen in-patients with a DSM-IV diagnosis of borderline, histrionic, or narcissistic PD were treated for 8 weeks with quetiapine at a dose of 400 mg/day in an open-label fashion. Effects on impulsivity (Barratt Impulsiveness Scale, BIS), depressive symptoms (Hamilton Depression Scale, HAMD, and Beck Depression Inventory, BDI) and side effects (Dosage Record and Treatment Emergent Symptom Scale, DOTES) were assessed. RESULTS: Twelve patients completed the study. No positive effect on impulsivity (BIS) was found, but a significant improvement on depression scores (HAM-D and BDI) was noted. Adverse effects that might have been due to study medication were mainly anticholinergic and mild-to-moderate. DISCUSSION: The data of our preliminary open-label study do not argue for a general recommendation of quetiapine for the treatment of impulsivity in cluster B PD, but indicate positive effects on depressive symptoms.

[Mixed episodes in bipolar disorder: a review]. / Affektive Mischzustände bei Bipolaren Störungen: ein Uberblick.

Affective mixed states in bipolar disorders are a current matter of scientific debate and represent a complex clinical picture with coexisting manic and depressive symptoms. Treatment of mixed states is regarded as an important challenge. As diagnostic uncertainties complicate systematic clinical evaluations of this patient group, generally accepted clinical treatment guidelines are lacking yet. In this review the significance as well as the problems and risks of new treatment options are discussed.

[Diabetes and depression]. / Diabetes und Depression.

Cohort studies indicate a high prevalence of depression in patients with diabetes mellitus. Despite numerous investigations, the underlying pathophysiologies of the metabolic abnormalities are poorly understood. A possible role play the increased counter-regulatory hormone release involved in glucose homeostasis, alterations in the glucose transport function and increased inflammatory activation triggered by depression. The diagnose of "depression" in diabetic patients might be hampered by similar symptoms of both conditions as fatigue, psychomotor inhibition, reduced appetite or sexual dysfunction. In treating depressive patients with diabetes one should consider potential induction or worsening of diabetes-like metabolic alterations. Selective serotonin-reuptake-inhibitors, venlafaxin and MAO-Inhibitors constitute a beneficial choice. Atypical antipsychotics like clozapine, olanzapine, quetiapine and risperidone should be given with precaution due to potential effects on glucose homeostasis.