Predicting performance in attention by measuring key metabolites in the PCC with 7T MRS.

The posterior cingulate cortex (PCC) is a key hub of the default mode network and is known to play an important role in attention. Using ultra-high field 7 Tesla magnetic resonance spectroscopy (MRS) to quantify neurometabolite concentrations, this exploratory study investigated the effect of the concentrations of myo-inositol (Myo-Ins), glutamate (Glu), glutamine (Gln), aspartate or aspartic acid (Asp) and gamma-amino-butyric acid (GABA) in the PCC on attention in forty-six healthy participants. Each participant underwent an MRS scan and cognitive testing, consisting of a trail-making test (TMT A/B) and a test of attentional performance. After a multiple regression analysis and bootstrapping for correction, the findings show that Myo-Ins and Asp significantly influence (p < 0.05) attentional tasks. On one hand, Myo-Ins shows it can improve the completion times of both TMT A and TMT B. On the other hand, an increase in aspartate leads to more mistakes in Go/No-go tasks and shows a trend towards enhancing reaction time in Go/No-go tasks and stability of alertness without signal. No significant (p > 0.05) influence of Glu, Gln and GABA was observed.

[Antidepressive agents and suicidal tendencies]. / Antidepressiva und Suizidalität.

In the last 2 years the discussions on the question whether antidepressants, especially selective serotonin reuptake inhibitors (SSRIs) can lead to suicidality, aggression and violence, flared up again. The available data on the problem, which has been discussed since the introduction of this substance group in the late 1980s, is presented in this article. A systematic literature search showed that a scientific consensus exists that the benefits of antidepressant pharmacotherapy in general, and of treatment with SSRIs and selective serotonin/norepinephrine reuptake inhibitors (SSNRIs) in particular, outweigh the risks of their use. This also applies to the treatment of children, adolescents and young adults. The agitation occasionally occurring at the beginning of treatment, which can be experienced as aversive in susceptible patients, can intensify or even trigger suicidal thoughts or impulses. This has to be paid particular attention to especially at the beginning of treatment. It is recommended that the indications for antidepressant pharmacotherapy of children, adolescents and young adults are assessed by a specialist.

[Basic principles of therapy with neuropsychotropic drugs]. / Grundprinzipien der Therapie mit Neuropsychopharmaka.

This review provides the general principles for a rational therapy with psychotropic drugs. It covers the discussion on the basics of the pharmacokinetics (with consideration of drug metabolism and the importance of genetic polymorphisms), pharmacodynamics (drug-receptor interaction, receptor pharmacology) and the effects of chronic administration of neuropsychotropic drugs on behavior. The reader will thus obtain the basis and stimulation for further study.

Therapeutic plasma concentrations of antidepressants and antipsychotics: lessons from PET imaging.

Therapeutic Drug Monitoring (TDM) of psychotropic drugs is strongly depending on the validity of recommended therapeutic plasma concentration reference ranges. Rational pharmacotherapy is based on the assumption that plasma concentrations are directly related to target occupancy by the respective drug. Here we show that positron emission tomography (PET) of molecular drug targets in the brain (neuroreceptors and transporters) allows for establishment of these relationships, thereby providing guidance for TDM services. Associations between brain target occupancy, plasma concentrations, and clinical effects and adverse reactions will be discussed for the most commonly used antidepressant and antipsychotic drugs.

[Antihistaminergic antipsychotics cause weight gain]. / Antihistaminerge Antipsychotika verursachen Gewichtszunahme.

In recent years, weight gain has increasingly gained attention as a side effect of antipsychotic therapy due to its metabolic and cardiovascular health risks and its negative effect on therapy compliance. The various antipsychotics show clear differences concerning their influence on body weight. These differences seem to be mainly due to the affinity of these substances to the histaminergic H1 receptors and due to serotonergic mechanisms. In the hypothalamus, the antihistaminergic effect of those antipsychotics which are associated with a high amount of weight gain leads to an increase of the activity of the adenosine monophosphate-activated protein kinase (AMPK). Hypothalamic AMPK activity has an integrative function regarding orexigenic and anorexigenic signals.