Reinhard Pietrowsky

Meta‐analysis of the effectiveness of psychological and pharmacological treatments for binge eating disorder

OBJECTIVE The aim of this study was to compute and compare mean effects of various treatments for binge eating disorder. METHOD A total of 38 studies with 1973 participants fulfilled the defined inclusion criteria. Effect sizes, odds ratios, and simple rates were integrated in fixed and random (mixed) effects categorical models. RESULTS From randomized controlled trials, psychotherapy and structured self-help, both based on cognitive behavioral interventions, were found to have large effects on the reduction of binge eating. Regarding pharmacotherapy, mainly comprising antidepressants, randomized controlled trials revealed medium effects for the reduction of binge eating. Uncontrolled studies on weight-loss treatments demonstrated moderate reductions of binge eating. Combination treatments did not result in higher effects compared with single-treatment regimens. Except for weight-loss treatment, none of the interventions resulted in a considerable weight reduction. DISCUSSION Psychotherapy and structured self-help, both based on cognitive-behavioral interventions, should be recommended as the first-line treatments.

An ultra short episode of sleep is sufficient to promote declarative memory performance

Various studies have demonstrated that a night of sleep has a beneficial effect on the retention of previously acquired declarative material. In two experiments, we addressed the question of whether this effect extends to daytime naps. In the first experiment we assessed free recall of a list of 30 words after a 60 min retention interval that was either filled with daytime napping or waking activity. Memory performance was significantly enhanced after napping as opposed to waking but was not correlated with time spent in slow wave sleep or total sleep time within the napping condition. The second experiment was designed to clarify the role of total sleep time and therefore included an additional third group, which was allowed to nap for no longer than 6 min on average. In comparing word recall after conditions of no napping (waking), short napping, and long napping, we found superior recall for both nap conditions in contrast to waking as well as for long naps in contrast to short naps. These results demonstrate that even an ultra short period of sleep is sufficient to enhance memory processing. We suggest that the mere onset of sleep may initiate active processes of consolidation which – once triggered – remain effective even if sleep is terminated shortly thereafter.

Brain potential changes after intranasal vs. intravenous administration of vasopressin: evidence for a direct nose-brain pathway for peptide effects in humans

There is evidence that intranasal application of peptides is a way to circumvent the blood-brain barrier. This led us to compare the effects of arginine-vasopressin (AVP) on event-related potentials (ERPs) in healthy men (n = 15) after intranasal and after intravenous (i.v.) administration. In a double-blind, crossover study, subjects received on three different occasions 20 IU of AVP intranasally (IN), 1.5 IU of AVP i.v., and saline solution. ERPs were recorded during the subjects performance on a auditory attention task. Plasma concentrations of vasopressin during task performance were enhanced after AVP, with the increase after i.v. administration of AVP exceeding that after AVP (p < 0.05). Intranasal administration of AVP substantially increased the P3 component of the ERP (p < 0.05). Intranasal administration of AVP substantially increased the P3 component of the ERP (< 0.01). By contrast, i.v. administration of AVP had no consistent effects on the ERP responses. In supplementary experiments as well, i.v. administration of lower doses of AVP (0.1 and 0.025 IU) did not affect the ERP. Plasma vasopressin concentrations after the 0.025 IU dose in these experiments were comparable to those after intranasal administration of 20 IU AVP. The results provide functional evidence that in the human brain effects of peptides like AVP may be facilitated after IN as compared to i.v. administration.

Enhanced dynamic complexity in the human EEG during creative thinking

This study shows that divergent thinking, considered the general process underlying creative production, can be distinguished from convergent, analytical thought based on the dimensional complexity of ongoing electroencephalographic (EEG) activity. EEG complexity over the central and posterior cortex was higher while subjects solved tasks of divergent than convergent thinking, and also higher than during mental relaxation. Over the frontal cortex, EEG complexity was comparable during divergent thinking and mental relaxation, but reduced during convergent thinking. Results indicate that the basic process underlying the generation of novel ideas expresses itself in a strong increase in the EEGs complexity, reflecting higher degrees of freedom in the competitive interactions among cortical neuron assemblies. Frontocortical EEG complexity being comparable with that during mental relaxation, speaks for a loosened attentional control during creative thinking.

Emotion and episodic memory in neuropsychiatric disorders

It has long been known that emotions can modulate learning and memory processes in humans and non-human mammals. Here we will review evidence from clinical, neuropsychological, neuroimaging and animal research suggesting an important role of emotions for the establishment of long-term episodic memories in the mammalian brain. In the first part of the review the neuroanatomical and neurochemical foundations of the interaction between brain areas generating emotions, such as the amygdala, and those allowing the association of multi-dimensional stimuli into an episodic memory, such as the hippocampus, are delineated. Patients with emotional and affective disorders show changes in memory performance in dependence of the positive or negative valence of the stimulus material. Furthermore, these patients often exhibit a reduced ability to access specific memories of life events with a striking lack of specific detail. Therefore, in the second part the clinical literature on memory impairments observed in patients with emotional and affective disorders, including post-traumatic stress disorder, schizophrenia and major depression, with a special emphasis on episodic memory function, is discussed. Finally, the relationship between memory deficits in Alzheimers disease and neurodegeneration in brain systems mediating emotions is reviewed.

Effects of sleep on the production of cytokines in humans.

The restorative functions of sleep may affect immunologic functioning.The present study examined the effects of sleep on stimulated cytokine release in 13 healthy men. The subjects spent 2 experimental nights in the sleep laboratory. In one condition, lights were turned off at 11:00 PM to enable sleep for 3.5 hours. Thereafter, they stayed awake till 7:00 AM. In the other condition, conversely, subjects stayed awake between 11:00 PM and 3:00 AM. Then, lights were turned off for a 3.5-hour phase of sleep. Blood was sampled every 30 minutes between 11:00 PM and 7:00 AM. Sleep was monitored by polysomnographic recordings. Release of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) was determined after stimulation of mononuclear cells with lipopolysaccharide from Escherichia coli. The release of IL-2 was stimulated with phytohe-magglutinin. Compared with wakefulness, after 3 hours of sleep, production of TNF-alpha and IL-1beta was substantially diminished (p <.01). Production of IL-2 was enhanced during sleep (p <.05), with this effect being limited to the second nocturnal sleep phase after 3:00 AM. Sleep-dependent changes in stimulated cytokine release were independent of changes in plasma cortisol concentrations. These results indicate a specific reducing effect of sleep (vs. wakefulness) on cytokine production by monocytes (TNF-alpha and IL-1beta). The rather slow development of the effects calls for further studies to establish the exact time course of the influence of sleep on cytokine production.

Effects of the menstrual cycle on auditory event-related potentials

Gonadal steroids (estradiol and progesterone) can alter neuronal functioning, but electrophysiological evidence in women is still sparse. Therefore, the present study investigated event-related potentials (ERPs) to neutral stimuli over the course of the menstrual cycle. In addition, associations between ERPs and salivary estradiol and progesterone concentrations were investigated. Eighteen young healthy women were tested at three different phases of their menstrual cycle (menses, and follicular and luteal phases). ERPs (i.e., the N1 and P2 components, reflecting cortical arousal and the orienting response, the N2, P3, and the Slow Wave (SW), reflecting controlled processing) were measured using two different paradigms. In the luteal phase, early ERPs reflecting the cortical arousal response were diminished in the first stimulus block indicating an attenuated orienting response. These changes were significantly correlated with estradiol as well as progesterone levels. As to the later ERP components, the N2 latency was shorter during menses compared to the other two phases. No menstrual cycle-associated changes were apparent in other late ERP components. In sum, this study documents changes in auditory ERPs across the menstrual cycle with the most prominent changes occurring during the luteal phase. Future ERP studies therefore need to be more attentive to the issue of menstrual phase when studying female subjects or female patients.

Dexamethasone blocks sleep induced improvement of declarative memory

To investigate the role of glucocorticoids for effects of early and late nocturnal sleep on declarative and procedural memory, 2 mg dexamethasone (versus placebo) were administered to healthy men 7 h prior to retention sleep. The retention sleep interval covered either the early or late half of nocturnal sleep. Following placebo, recall of a paired associate list (declarative memory) benefitted more from early than late sleep and recall of mirror tracing skills (procedural memory) benefitted more from late than early sleep. Dexamethasone did not affect slow wave sleep dominating early sleep, but blocked the beneficial effect of early sleep on recall of paired associates. Conversely, dexamethasone reduced rapid eye movement sleep dominating late sleep, but did not affect late sleeps beneficial effect on mirror tracing skills. The natural inhibition of endogenous glucocorticoid secretion during early sleep seems to be essential for a sleep-related facilitation of declarative memory.

A nose-brain pathway for psychotropic peptides : Evidence from a brain evoked potential study with cholecystokinin

Abstract The access of substances to the brain is of particular relevance for the etiology and treatment of psychiatric and neurologic diseases. This study provides functional evidence for a direct access of peptides to the human brain after intranasal administration. Effects were compared of intranasal (IN, 10 μg) and intravenous (IV, 0.25 and 2.5 μg) administered cholecystokinin-8 (CCK) on the auditory event related potential (AERP) in 20 healthy subjects. Also, plasma concentration of cortisol and ACTH were monitored. The study was designed as a placebo-controlled, double-blind within-subject cross-over comparison. AERPs were recorded while the subject performed on an attention task (oddball task). Plasma CCK concentrations after IN administration of CCK were comparable to those after IV administration of 0.25 μg CCK, but were substantially lower than those after 2.5 μg CCK. The P3 complex of the AERP was markedly increased following the IN administration of CCK (p < .01) compared to placebo and to the IV administration of 0.25 μg This pattern was more obvious in women than men. Increases in plasma ACTH concentrations after CCK reached significance selectively following the IN mode of administration (p < .01).

Behavioral Effects of Nightmares and Their Correlations to Personality Patterns

Factors affecting or inducing nightmares have been investigated repeatedly. However, little research is carried out on the behavioral consequences of nightmares. The present study thus served to investigate behavioral effects of nightmares in correlation to personality variables. 41 non-clinical participants, who suffer from about 2 nightmares per month recorded their dreams and nightmares over a 4-week period. A nightmare was defined as a dream that frightens the dreamer and could be recalled in detail on awakening. Anxiety and mood were monitored every morning. All nightmares and their behavioral consequences were noted on a questionnaire. Personality traits and life events were assessed at the beginning of the investigation. 100 nightmares were reported by the subjects over the 4-week period (range: 0–8). Following a nightmare, the subjects were significantly more anxious and were of a less stable mental condition compared to nights without nightmares. Additionally, nightmares induced physical complaints. This was considered to be an indicator that something was wrong in their lives and induced them to solve personal problems. The behavioral effects were most pronounced in subjects scoring high on neuroticism and on the number of physical complaints and low on achievement orientation and openness. The results suggest that sufferers of nightmares intend to change their lives, especially those with a neurotic-like personality.