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Background: Although there are several human experimental studies on short-term effects of radiofrequency electromagnetic fields (RF-EMF) on sleep, the role of effect modification by sex or age in this context has not yet been considered. In an earlier study, we observed sex differences in RF-EMF effects in elderly subjects. The present study investigated possible RF-EMF effect modifications by age in men., Methods: Data available for the present analysis come from three double-blind, randomized cross-over studies, in which effects of different RF-EMF exposure signals on sleep were investigated in young [sample 1: 25.3 (mean) ± 2.6 (SD) years; sample 2: 25.4 ± 2.6 years; n = 30, respectively] and older (69.1 ± 5.5 years; n = 30) healthy male volunteers. Studies comprised a screening/adaptation night followed by nine experimental nights at two-week intervals. RF-EMF exposure effect modifications by age were analysed for two different exposure signals (GSM900 at 2 W/kg, TETRA at 6 W/kg), each compared to a sham exposure. Polysomnography, during which the exposure signals were delivered by a head worn antenna, as well as sleep staging were performed according to the AASM standard. Four subjective and 30 objective sleep parameters were statistically analysed related to possible RF-EMF effects., Results: Comparisons of sleep parameters observed under sham exposure revealed highly pronounced physiological differences between young and elderly men. A consistent exposure effect in both age groups was found for a shorter latency to persistent sleep under TETRA exposure reflecting a sleep-promoting effect. Exposure effect modifications by age were observed for two of the four self-reported sleep parameters following GSM900 exposure and for arousals during REM sleep under TETRA exposure., Conclusions: As effects of a short-term all-night RF-EMF exposure on sleep occurred only sporadically in young and elderly men, it seems that age doesn't matter in this respect. However, as long as there are no corresponding data from young healthy women that would allow a comparison with the data from elderly women, this assumption cannot be conclusively verified. Nevertheless, the present results are not indicative of any adverse health effects., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Results from human experimental studies investigating possible effects of radiofrequency electromagnetic fields (RF-EMF) on sleep are heterogeneous. So far, there is no study on possible sex-differences in RF-EMF effects., Objectives: The present study aimed at analyzing differences in RF-EMF effects on the macrostructure of sleep between healthy elderly males and females., Methods: With a double-blind, randomized, sham-controlled cross-over design effects of two RF-EMF exposures (GSM900 and TETRA) on sleep were investigated in samples of 30 elderly healthy male and 30 healthy elderly female volunteers. Participants underwent each of the three exposure conditions on three occassions following an individually randomized order resulting in a total of nine study nights per participant. Exposure was delivered for 30 min prior to sleep and for the whole night (7.5 h) by a head worn antenna specifically designed for the projects. The peak spatial absorption rate averaged over time in head tissues (psSAR10g) was 6 W/kg for TETRA and 2 W/kg for GSM900. Thirty variables characterising the macrostructure of sleep and arousals as well as four subjective sleep variables were considered for statistical analyses., Results: Multivariate analyses revealed that exposure to GSM900 and/or TETRA resulted in a significant reduction in arousals, a shorter latency to sleep stage N3, and a shorter self-reported time awake after sleep in both males and females. Exposure effects depending on sex (significant interactions) were observed. Latency to sleep stage R was shorter in females and tended to be longer in males under both exposures. Latency to stage N3 was shorter in females under TETRA exposure and almost not affected in males. The time awake within the sleep period under TETRA exposure was shorter in females and only slightly longer in males. Under GSM exposure, the self-rated total sleep time tended to be longer in females and to be shorter in males. Finally, the number of awakenings was lower only in females and tended to be higher in males under GSM exposure., Discussion: With regard to RF-EMF effects on human sleep it seems that gender matters since GSM900 and TETRA led to significantly more exposure effects in females. Regardless of gender, none of the observed changes is indicative of a sleep disturbing effect of RF-EMF exposure. Observed effects might be mediated by skin related thermoregulatory mechanisms., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Studies on effects of radio frequency-electromagnetic fields (RF-EMF) on the macrostructure of sleep so far yielded inconsistent results. This study investigated whether possible effects of RF-EMF exposure differ between individuals., Objective: In a double-blind, randomized, sham-controlled cross-over study possible effects of electromagnetic fields emitted by pulsed Global System for Mobile Communications (GSM) 900 and Wideband Code-Division Multiple Access (WCDMA)/Universal Mobile Telecommunications System (WCDMA/UMTS) devices on sleep were analysed., Methods: Thirty healthy young men (range 18-30 years) were exposed three times per exposure condition while their sleep was recorded. Sleep was evaluated according to the American Academy of Sleep Medicine standard and eight basic sleep variables were considered., Results: Data analyses at the individual level indicate that RF-EMF effects are observed in 90% of the individuals and that all sleep variables are affected in at least four subjects. While sleep of participants was affected in various numbers, combinations of sleep variables and in different directions, showing improvements but also deteriorations, the only consistent finding was an increase of stage R sleep under GSM 900MHz exposure (9 of 30 subjects) as well as under WCDMA/UMTS exposure (10 of 30 subjects)., Conclusions: The results underline that sleep of individuals can be affected differently. The observations found here may indicate an underlying thermal mechanism of RF-EMF on human REM sleep. Nevertheless, the effect of an increase in stage R sleep in one third of the individuals does not necessarily indicate a disturbance of sleep., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background: Studies have shown that exposure to radiofrequency electromagnetic fields (RF-EMF) in the mobile communication frequency range may induce physiological modifications of both spontaneous as well as event-related human electroencephalogram. So far, there are very few peer-reviewed studies on effects of Terrestrial Trunked Radio (TETRA), which is a digital radio communication standard used by security authorities and organizations in several European countries, on the central nervous system., Objectives: To analyze the impact of simulated TETRA handset signals at 385 MHz on slow cortical potentials (SCPs)., Methods: 30 young healthy males (25.2±2.7 years) were exposed in a double-blind, counterbalanced, cross-over design to one of three exposure levels (TETRA with 10 g averaged peak spatial SAR: 1.5 W/kg, 6.0 W/kg and sham). Exposure was conducted with a body worn antenna (especially designed for this study), positioned at the left side of the head. Subjects had 9 test sessions (three per exposure condition) in which three SCPs were assessed: SCP related to a clock monitoring task (CMT), Contingent negative variation (CNV) and Bereitschaftspotential (BP)., Results: Neither behavioral measures nor the electrophysiological activity was significantly affected by exposure in the three investigated SCP paradigms. Independent of exposure, significant amplitude differences between scalp regions could be observed for the CMT-related SCP and for the CNV., Conclusions: The present results reveal no evidence of RF-EMF exposure-dependent brain activity modifications investigated at the behavioral and the physiological level., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background: TETRA (terrestrial trunked radio) is a digital radio communication standard, which has been implemented in several European countries and is used by public executives, transportation services, and by private companies. Studies on possible impacts on the users' health considering different exposure conditions are missing., Objectives: To investigate possible acute effects of electromagnetic fields (EMF) of two different levels of TETRA hand-held transmitter signals on cognitive function and well-being in healthy young males., Methods: In the present double-blind cross-over study possible effects of short-term (2.5h) EMF exposure of handset-like signals of TETRA (385 MHz) were studied in 30 healthy male participants (mean±SD: 25.4±2.6 years). Individuals were tested on nine study days, on which they were exposed to three different exposure conditions (Sham, TETRA 1.5 W/kg and TETRA 6.0 W/kg) in a randomly assigned and balanced order. Participants were tested in the afternoon at a fixed timeframe., Results: Attention remained unchanged in two out of three tasks. In the working memory significant changes were observed in two out of four subtasks. Significant results were found in 5 out of 35 tested parameters, four of them led to an improvement in performance. Mood, well-being and subjective somatic complaints were not affected by TETRA exposure., Conclusions: The results of the present study do not indicate a negative impact of a short-term EMF-effect of TETRA on cognitive function and well-being in healthy young men., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background: Although electroconvulsive therapy (ECT) is the most effective acute antidepressant intervention, sustained response rates are low. It has never been systematically assessed whether psychotherapy, continuation ECT, or antidepressant medication is the most efficacious intervention to maintain initial treatment response., Methods: In a prospective, randomized clinical trial, 90 inpatients with major depressive disorder (MDD) were treated with right unilateral ultra-brief acute ECT. Electroconvulsive therapy responders received 6 months guideline-based antidepressant medication (MED) and were randomly assigned to add-on therapy with cognitive-behavioral group therapy (CBT-arm), add-on therapy with ultra-brief pulse continuation electroconvulsive therapy (ECT-arm), or no add-on therapy (MED-arm). After the 6 months of continuation treatment, patients were followed-up for another 6 months. The primary outcome parameter was the proportion of patients who remained well after 12 months., Results: Of 90 MDD patients starting the acute phase, 70% responded and 47% remitted to acute ECT. After 6 months of continuation treatment, significant differences were observed in the three treatment arms with sustained response rates of 77% in the CBT-arm, 40% in the ECT-arm, and 44% in the MED-arm. After 12 months, these differences remained stable with sustained response rates of 65% in the CBT-arm, 28% in the ECT-arm, and 33% in the MED-arm., Conclusions: These results suggest that ultra-brief pulse ECT as a continuation treatment correlates with low sustained response rates. However, the main finding implicates cognitive-behavioral group therapy in combination with antidepressants might be an effective continuation treatment to sustain response after successful ECT in MDD patients., (Copyright © 2014 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.)

Background: Studies in young healthy volunteers provided evidence of a beneficial impact of an anodal time-varied transcranial direct current stimulation (tDCS) during early slow wave rich sleep on declarative memory but not on procedural memory., Objective/hypothesis: The present study investigated whether sleep-dependent memory consolidation can also be affected by slow oscillating tDCS in a population of elderly subjects., Methods: 26 subjects (69.1 years ± 7.7 years) received bi-frontal anodal stimulation (max. current density: 0.331 mA/cm(2)) during early NREM sleep in a double-blind placebo-controlled randomized crossover study. Stimulation effects on offline consolidation were tested by using a declarative and a procedural memory task. Furthermore, sleep stages were scored, EEG power was analyzed and spindle densities were assessed., Results: Independently from stimulation condition, performance in both memory tasks significantly decreased overnight. Stimulation revealed no significant effect on sleep-dependent memory consolidation. Verum tDCS was accompanied by significantly more time awake and significantly less NREM stage 3 sleep during five 1-min stimulation free intervals., Conclusions: The results of the present study are in line with other studies showing that offline consolidation during sleep varies with age and is less pronounced in the elderly than in young or middle-aged subjects. Contrary to an almost identical positive study in young adults, slow oscillatory tDCS applied to the elderly failed to show a beneficial effect on memory consolidation in the present study., (Copyright © 2013 Elsevier Inc. All rights reserved.)

The neurotrophins nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) are important mediators of brain and neuronal development, the maintenance of homeostatic conditions in the adult nervous system, and the complex interplay of central and peripheral physiological and pathophysiological factors. To date there are few studies examining blood concentrations of neurotrophic factors in large samples of healthy and diseased individuals and no published study specifically addresses peripheral BDNF and NGF levels in late life. Using improved highly sensitive and specific fluorometric two-site enzyme-linked immunosorbent assays we examined BDNF (n=465) and NGF (n=175) serum levels in a large cohort of elderly individuals (age range: 70-103 years). Neither BDNF nor NGF serum levels proved to be normally distributed, indicating that previously published studies with small sample sizes using parametric testing may be misleading. A significant correlation was found between BDNF and platelet count (r=0.344, p<0.01), age and BDNF protein (r=-0.101, p=0.029) and BDNF and NGF serum levels (r=0.152, p=0.04). No other major influencing factors were found including gender, depression, and dementia.

Background: Recent findings in young adults suggest that rapid eye movement (REM) sleep plays a role in procedural memory consolidation. The significance of REM sleep for memory consolidation in old age has not yet been investigated., Methods: Effects of REM sleep manipulation on declarative and procedural memory consolidation were investigated in 107 healthy older adults, ages 60-82 years. Rapid eye movement sleep deprivation was achieved by REM sleep awakenings and compared with non-REM sleep awakenings. Rapid eye movement sleep augmentation was realized physiologically by REM sleep rebound and pharmacologically by administering an acetylcholinesterase inhibitor in a double-blind, placebo-controlled design. Memory performance was tested by a paired associate list and a mirror tracing task at 9:30 pm and 7:30 am with sleep intervening between 11:00 pm and 7:00 am., Results: Although REM sleep deprivation led to a significant reduction in total and phasic REM sleep, memory consolidation remained unaffected. Both REM sleep augmentation groups showed a significant increase in phasic REM sleep, whereas only pharmacological cholinergic REM sleep manipulation exerted a significant positive effect on procedural memory consolidation., Conclusions: Because only after cholinergic stimulation of phasic REM sleep procedural memory consolidation is improved, cholinergic activation seems to be a crucial component of REM sleep-related memory consolidation in old age.

Background: Several lines of evidence suggest that central cortical inhibitory mechanisms, especially associated with gamma-aminobutyric acid (GABA) neurotransmission, may play a role in the pathophysiology of major depression. Transcranial magnetic stimulation is a useful tool for investigating central cortical inhibitory mechanisms associated with GABAergic neurotransmission in psychiatric and neurological disorders., Methods: By means of transcranial magnetic stimulation, different parameters of cortical excitability, including motor threshold, the cortical silent period, and intracortical inhibition/facilitation, were investigated in 20 medication-free depressed patients and 20 age- and gender-matched healthy volunteers., Results: Silent period and intracortical inhibition were reduced in depressed patients, consistent with a reduced GABAergic tone. Moreover, patients showed a significant hemispheric asymmetry in motor threshold., Conclusions: This study provides evidence of reduced GABAergic tone and motor threshold asymmetry in patients with major depression.