Prevalence and burden of bipolar disorders in European countries

A literature search, supplemented by an expert survey and selected reanalyses of existing data from epidemiological studies was performed to determine the prevalence and associated burden of bipolar I and II disorder in EU countries. Only studies using established diagnostic instruments based on DSM-III-R or DSM-IV, or ICD-10 criteria were considered. Fourteen studies from a total of 10 countries were identified. The majority of studies reported 12-month estimates of approximately 1% (range 0.5–1.1%), with little evidence of a gender difference. The cumulative lifetime incidence (two prospective-longitudinal studies) is slightly higher (1.5–2%); and when the wider range of bipolar spectrum disorders is considered estimates increased to approximately 6%. Few studies have reported separate estimates for bipolar I and II disorders. Age of first onset of bipolar disorder is most frequently reported in late adolescence and early adulthood. A high degree of concurrent and sequential comorbidity with other mental disorders and physical illnesses is common. Most studies suggest equally high or even higher levels of impairments and disabilities of bipolar disorders as compared to major depression and schizophrenia. Few data are available on treatment and health care utilization

On the relationship of first-episode psychosis to the amphetamine-sensitized state: a dopamine D2/3 receptor agonist radioligand study.

Schizophrenia is characterized by increased behavioral and neurochemical responses to dopamine-releasing drugs. This prompted the hypothesis of psychosis as a state of "endogenous" sensitization of the dopamine system although the exact basis of dopaminergic disturbances and the possible role of prefrontal cortical regulation have remained uncertain. To show that patients with first-episode psychosis release more dopamine upon amphetamine-stimulation than healthy volunteers, and to reveal for the first time that prospective sensitization induced by repeated amphetamine exposure increases dopamine-release in stimulant-naïve healthy volunteers to levels observed in patients, we collected data on amphetamine-induced dopamine release using the dopamine D2/3 receptor agonist radioligand [11C]-(+)-PHNO and positron emission tomography. Healthy volunteers (n = 28, 14 female) underwent a baseline and then a post-amphetamine scan before and after a mildly sensitizing regimen of repeated oral amphetamine. Unmedicated patients with first-episode psychosis (n = 21; 6 female) underwent a single pair of baseline and then post-amphetamine scans. Furthermore, T1 weighted magnetic resonance imaging of the prefrontal cortex was performed. Patients with first-episode psychosis showed larger release of dopamine compared to healthy volunteers. After sensitization of healthy volunteers their dopamine release was significantly amplified and no longer different from that seen in patients. Healthy volunteers showed a negative correlation between prefrontal cortical volume and dopamine release. There was no such relationship after sensitization or in patients. Our data in patients with untreated first-episode psychosis confirm the "endogenous sensitization" hypothesis and support the notion of impaired prefrontal control of the dopamine system in schizophrenia

Natural course and burden of bipolar disorders

Despite an abundance of older and more recent retrospective and considerably fewer prospective-longitudinal studies in bipolar disorders I and II, there are still remarkable deficits with regard to our knowledge about the natural course and burden. The considerable general and diagnosis-specific challenges posed by the nature of bipolar disorders are specified, highlighting in particular problems in diagnostic and symptom assessment, shifts in diagnostic conventions and the broadening of the diagnostic concept by including bipolar spectrum disorders. As a consequence it still remains difficult to agree on several core features of bipolar disorders, such as when they begin, how many remit spontaneously and how many take a chronic course. On the basis of clinical and epidemiological findings this paper summarizes (i) a significant need to extend the study of the natural course of bipolar disorder in clinical samples beyond the snapshot of acute episodes to the study of the mid-term and long-term symptom course, associated comorbidities and the associated burden of the disease. (ii) In terms of epidemiological studies, that are also of key importance for resolving the critical issues of threshold definitions in the context of the bipolar spectrum concept, there is a clear need for identifying the most relevant risk factors for the first onset and those for the further illness progression in early stages. Since there are some indications that these critical processes might start as early as adolescence, such studies might concentrate on young cohorts and clearly before these prospective patients come to clinical attention. (iii) The value of both types of studies might be enhanced, if beyond the use of standardized diagnostic interview, special attempts are made to use prospective life- and episode-charting methods for bipolar illnesses

Recurrent brief depression - past and future

Recurrent brief depressive disorder (RBD) is a well-defined and significantly prevalent affective disorder with an increased risk of suicidal behavior and significant clinical impairment in the community and general practice. RBD is characterized by depressive episodes occurring at least once a month and lasting for only a few days. The lifetime co-occurrence of both RBD and major depressive disorder (MDD), called combined depression (CD), increases substantially the risk for suicide attempts, even more than is known for "pure" MDD. Diagnostic criteria for RBD can be found in the ICD-10 and DSM-IV and are helpful in both, research and clinical routine. Furthermore, several methodological issues are covered in this paper, which make clinical diagnostic and drug response evaluation of RBD very different from MDD. However, clinical procedures rather bear a resemblance to those used in the treatment of migraine or epilepsy. Formal differences in the course of RBD and MDD create different needs concerning the design of drug treatment studies. Absence of special methodological requirements and highly selected patient samples has probably been responsible for false negative results in double-blind, placebo-controlled treatment studies. Although several authors reported successful treatment of RBD with different compounds in about 60 patients, it is still not possible to deduce a treatment algorithm for RBD to date. Obviously, future treatment studies without the limitations of previous studies are clearly required for RBD

Effect of carbonaceous soil amendments on potential mobility of weak acid herbicides in soil

4 pages, 4 references. Functions of Natural Organic Matter in Changing Environment presents contributions from the 16th Meeting of the International Humic Substances Society (IHSS 16) held in Hangzhou, China on September 9-14, 2012.Use of carbonaceous amendments in soil has been proposed to decrease potential off-site transport of weak acid herbicides and metabolites by increasing their sorption to soil. The effects of organic olive mill waste, biochars from different feed stocks, and humic acid bound to clay on sorption of 4-chloro-2-methylphenoxyacetic acid (MCPA), aminocyclopyrachlor, or indaziflam acid metabolite to soils with varying physical and chemical properties were determined. At natural agricultural pH soil levels, these chemicals are anionic and weakly sorbed to soils; sorption of the three weak acids on soil was in the order MCPA (K f = 0.1) 10,000×. While generalizations have been made that soil sorption of nonpolar, neutral, or weakly basic chemicals increases by the addition of different carbonaceous amendments, no such generalizations can be made for weak acids. More work on properties of these amendments, biochars in particular, and how they affect weak acid sorption is required.Peer reviewe

The Spectral Diversity of Resting-State Fluctuations in the Human Brain

In order to assess whole-brain resting-state fluctuations at a wide range of frequencies, resting-state fMRI data of 20 healthy subjects were acquired using a multiband EPI sequence with a low TR (354 ms) and compared to 20 resting-state datasets from standard, high-TR (1800 ms) EPI scans. The spatial distribution of fluctuations in various frequency ranges are analyzed along with the spectra of the time-series in voxels from different regions of interest. Functional connectivity specific to different frequency ranges (<0.1 Hz; 0.1-0.25 Hz; 0.25-0.75 Hz; 0.75-1.4 Hz) was computed for both the low-TR and (for the two lower-frequency ranges) the high-TR datasets using bandpass filters. In the low-TR data, cortical regions exhibited highest contribution of low-frequency fluctuations and the most marked low-frequency peak in the spectrum, while the time courses in subcortical grey matter regions as well as the insula were strongly contaminated by high-frequency signals. White matter and CSF regions had highest contribution of high-frequency fluctuations and a mostly flat power spectrum. In the high-TR data, the basic patterns of the low-TR data can be recognized, but the high-frequency proportions of the signal fluctuations are folded into the low frequency range, thus obfuscating the low-frequency dynamics. Regions with higher proportion of high-frequency oscillations in the low-TR data showed flatter power spectra in the high-TR data due to aliasing of the high-frequency signal components, leading to loss of specificity in the signal from these regions in high-TR data. Functional connectivity analyses showed that there are correlations between resting-state signal fluctuations of distant brain regions even at high frequencies, which can be measured using low-TR fMRI. On the other hand, in the high-TR data, loss of specificity of measured fluctuations leads to lower sensitivity in detecting functional connectivity. This underlines the advantages of low-TR EPI sequences for resting-state and potentially also task-related fMRI experiments