A preliminary investigation of impulsivity, aggression and white matter in patients with bipolar disorder and a suicide attempt history.

BACKGROUND: Impulsivity and aggression may be associated with suicide attempts in bipolar disorder (BD), but findings have been inconsistent. Abnormalities in anterior white matter tracts that project to the frontal lobes mediate top-down regulation of emotion and may contribute to this clinical phenomenology. METHODS: We assessed white matter (i.e., fractional anisotropy) in anterior and posterior brain regions using diffusion tensor imaging in 18 patients with BD and no prior suicide attempt (BD-S), 12 patients with BD and a prior suicide attempt (BD+S), and 12 healthy volunteers. Patients completed the Urgency, Premeditation, Perseverance, Sensation Seeking, Positive Urgency (UPPS-P) Impulsive Behavior Scale and Impulsive Premeditated Aggression Scale (IPAS). All individuals completed the Barratt Impulsiveness Scale (BIS-11). RESULTS: Patients with BD+S had higher overall impulsivity (assessed using both the UPPS-P Impulsive Behavior Scale and BIS-11) and premeditated aggression compared to patients with BD-S. There were no significant group differences on measures of fractional anisotropy (FA). In patients with BD+S, however, higher FA in the anterior (but not the posterior) brain regions correlated with greater overall impulsivity on the UPPS-P Impulsive Behavior Scale. There were no significant correlations between either anterior or posterior brain regions with clinical measures in patients with BD-S. LIMITATIONS: Cross-sectional study, sample size and possible contribution of psychotropic medications. CONCLUSION: Impulsivity and aggression may be risk factors for a suicide attempt in BD. White matter in the anterior limb of the internal capsule and anterior corona radiata may play a role in this phenomenology.

Visions for the North Sea: the societal dilemma behind specifying good environmental status.

We augment discussions about the Good Environmental Status of the North Sea by developing two extreme visions and assessing their societal benefits. One vision ('Then') assumes restoration of benthic functioning; we contend that trawling had already degraded the southern North Sea a century ago. Available information is used to speculate about benthic functioning in a relatively undisturbed southern North Sea. The second vision ('Now') draws on recent benthic functioning. The supply of five ecosystem services, supported by benthic functioning, is discussed. 'Then' offers confidence in the sustainable supply of diverse services but restoration of past function is uncertain and likely to be paired with costs, notably trawling restraints. 'Now' delivers known and valued services but sustained delivery is threatened by, for example, climate change. We do not advocate either vision. Our purpose is to stimulate debate about what society wants, and might receive, from the future southern North Sea.

Early intervention for adolescents at high risk for the development of bipolar disorder: pilot study of Interpersonal and Social Rhythm Therapy (IPSRT).

Interpersonal and Social Rhythm Therapy (IPSRT) delays bipolar disorder (BP) recurrence in adults by stabilizing daily routines and sleep/wake cycles. Because adolescence is a key developmental stage for illness onset and altered social and sleep patterns, this period may prove optimal for intervention with adolescents at-risk for BP. We describe a treatment development trial of IPSRT for adolescents at-risk for BP by virtue of a positive family history. Adolescents with a first-degree relative with BP were evaluated for Axis I psychopathology via semistructured interview, and relatives' BP diagnoses were confirmed via record review. IPSRT consisted of 12 sessions delivered over 6 months. Outcome variables including sleep, mood symptoms, and functioning were assessed via clinician interview and self-/parent-report at pretreatment, 3 months, and posttreatment (6 months). Thirteen adolescents attended at least one IPSRT session. Half of the sample denied Axis I psychopathology at intake; the remainder met criteria for a range of internalizing and externalizing disorders. Families reported high satisfaction with IPSRT, yet, on average, participants attended about half of scheduled sessions. Missed sessions were primarily associated with parental BP illness severity. Data indicate significant change in select sleep/circadian patterns (i.e., less weekend sleeping in and oversleeping) with treatment. Preliminary data suggest the IPSRT focus on stabilizing daily rhythms and interpersonal relationships may be beneficial for adolescents at-risk for BP. Controlled trials with longitudinal follow-up are needed to examine whether early intervention for at-risk youth helps prevent or delay disorder.

Clinical and cognitive correlates of suicide attempts in bipolar disorder: is suicide predictable?

OBJECTIVE: We conducted a retrospective investigation of potential clinical, demographic, and neuropsychological risk factors for suicide attempts in patients diagnosed with bipolar disorder. METHOD: Participants included 67 adult inpatients and outpatients aged 18-60 years meeting DSM-IV criteria for bipolar disorder (bipolar I and II disorders, bipolar disorder not otherwise specified). We assessed demographic factors, mood symptoms, psychosis, trauma history, trait impulsivity, trait aggression, and reasons for living. The primary outcome measures were the Barratt Impulsiveness Scale-version II, Aggression Questionnaire, and 10 cognitive outcome variables. The cognitive outcome variables assessed cognitive performance across several domains, including processing speed, attention, verbal learning, and executive function. Another aspect of cognitive function, decision making, was assessed using the Iowa Gambling Task. The study was conducted from July 2007-July 2009. RESULTS: We found that nonattempters reported significantly higher trait impulsivity scores on the Barratt Impulsiveness Scale compared to attempters (t(57) = 2.2, P = .03) and that, among attempters, lower trait impulsivity score was associated with higher scores of lethality of prior attempts (r(25) = -0.53, P = .01). Analyses revealed no other group differences on demographic, clinical, or neurocognitive variables when comparing attempters versus nonattempters. Regression models failed to identify any significant predictors of past suicide attempt. CONCLUSIONS: The largely negative results of our study are particularly important in highlighting the clinical dilemma faced by many clinicians when trying to predict which patients will make serious suicide attempts and which patients are at a lower risk for acting on suicidal thoughts. A limitation of our work is that we examined stable trait measures of impulsivity among a euthymic sample rather than mood state or the impact of mood state on traits. Overall, we conclude that suicidal behavior is extremely difficult to predict, even when comprehensive clinical and neurocognitive information is available.

Grey matter volume reductions in the emotion network of patients with depression and coronary artery disease.

Coronary Artery Disease (CAD) and Major Depressive Disorder (MDD) commonly co-occur and may be linked by a network of brain regions involved in emotion regulation, including the orbitofrontal cortex, amygdala/parahippocamal region and insula. We hypothesized structural differences in this emotion network more prominently in CAD+MDD versus CAD and healthy control (CTRL) groups that do not involve depression-related emotion circuitry. In contrast, we hypothesized structural similarities between CAD+MDD and MDD groups, both involving depression-related circuitry. We obtained structural magnetic resonance imaging scans from age-matched consenting subjects (CAD+MDD, n = 12; CAD, n = 12; MDD, n = 19; CTRL, n = 17) and performed a region of interest analysis. We found decreased grey matter volumes in the bilateral orbitofrontal cortex, bilateral amygdala/parahippocampal gyrus and right insula in CAD+MDD versus CTRL subjects and decreased grey matter volumes in the bilateral amygdala/parahippocampal regions in CAD+MDD versus CAD subjects. We found grey matter reductions in the right orbitofrontal cortex of CAD+MDD versus MDD subjects, and reductions in right insula of CAD versus CRTL subjects. Our results support that the network of brain regions involved in emotion regulation may be relevant to the relationship between CAD and MDD.

Major dimensions in food-web structure properties.

The covariance among a range of 20 network structural properties of food webs plus net primary productivity was assessed for 14 published food webs using principal components analysis. Three primary components explained 84% of the variability in the data sets, suggesting substantial covariance among the properties employed in the literature. The first dimension explained 48% of the variance and could be ascribed to connectance, covarying significantly with the proportion of intermediate species and characteristic path length. The second dimension explained 19% and was related to trophic species richness. The third axis explained 17% and was related to ecosystem net primary productivity. A distinct opposite clustering of connectance, the proportion of intermediate species, and mean trophic level vs. the proportion of top and basal species and path length suggests a dichotomy in food-web structure. Food webs appear either clustered and highly interconnected or elongated with fewer links.

Nutrient budgets for European seas: a measure of the effectiveness of nutrient reduction policies.

Socio-economic development in Europe has exerted increasing pressure on the marine environment. Eutrophication, caused by nutrient enrichment, is evident in regions of all European seas. Its severity varies but has, in places, adversely impacted socio-economic activities. This paper aims to evaluate the effectiveness of recently adopted policies to reduce anthropogenic nutrient inputs to European seas. Nitrogen and phosphorus budgets were constructed for three different periods (prior to severe eutrophication, during severe eutrophication and contemporary) to capture changes in the relative importance of different nutrient sources in four European seas suffering from eutrophication (Baltic Proper, coastal North Sea, Northern Adriatic and North-Western Black Sea Shelf). Policy success is evident for point sources, notably for P in the Baltic and North Seas, but reduction of diffuse sources has been more problematic.

Comparison of manual and computer-automated procedures for tinnitus pitch-matching.

Clinical assessment of tinnitus usually includes pitch-matching between the tinnitus and a pure tone. Although such testing is performed routinely, response reliability has not been demonstrated yet. The present study continues a series of studies designed to develop automated methodology for quantifying tinnitus perceptual characteristics. Three methods for tinnitus pitch-matching were performed in a group of 42 subjects. Two methods were computer-automated (Binary and Subject-Guided) and the third method was a traditional manual technique. Each method provided excellent response reliability for about half of the subjects. The most reliable subjects, however, differed widely between the different methods. Each subject provided a total of 14 pitch matches using the three different methods. Analyses based on each subject's total of 14 pitch matches revealed the range of pitch matches for each subject. About half of the subjects selected pitch matches over a range of 2 1/3 octaves. Results of this study suggest that specifying the range of tinnitus pitch matches rather than attempting to identify a single pitch match may be more appropriate.

Integrating rewards and cognition in the frontal cortex.

Research indicates that the dorsolateral prefrontal cortex (DLPFC) contributes to working memory and executive control, whereas the ventral frontal cortex (VFC) contributes to affective and motivational processing. Few studies have examined both the functional specificity and the integration of these regions. We did so using fMRI and a verbal working memory task in which visual cues indicated whether recall performance on an upcoming trial would be linked to a monetary reward. On the basis of prior findings obtained in delayed response tasks performed by nonhuman primates, we hypothesized that (1) VFC would show an increase only in response to a cue indicating potential for a monetary reward; (2) DLPFC would show sustained activity across a delay interval for all trials, though activity in rewarded trials would be enhanced; and (3) regions engaged in speech-based rehearsal would be relatively insensitive to monetary incentive. Our hypotheses about DLPFC and rehearsal-related regions were confirmed. In VFC regions, we failed to observe statistically significant effects of reward when the cue or delay epochs of the task were examined in isolation. However, an unexpected and significant deactivation was observed in VFC during the delay epoch; furthermore, a post hoc voxelwise analysis indicated a complex interaction between (1) the cue and delay epochs of the task and (2) the reward value of the trials. The pattern of activation and deactivation across trial types suggests that VFC is sensitive to reward cues, and that portions of DLPFC and VFC may work in opposition during the delay epoch of a working memory task in order to facilitate task performance.

Reliability of computer-automated hearing thresholds in cochlear-impaired listeners using ER-4B Canal Phone earphones.

This paper describes the second phase of a study to determine test-retest reliability of hearing thresholds using a computer-automated technique with ER-4B Canal Phone insert earphones. The first phase documented reliable hearing thresholds in 20 normal-hearing individuals. For this second phase, 20 individuals with cochlear hearing loss completed the same testing protocol as for phase one. During each of two sessions, hearing thresholds were obtained in one-third octave steps at 500 Hz to 16,000 Hz. The octave frequencies were immediately retested, followed by ear-tip reinsertion and further retesting at octave frequencies. Both groups showed overall good threshold reliability, with observable differences between groups. First, repeated testing resulted in improved hearing thresholds for the normal-hearing group, but not for the cochlear-loss group. Second, the normal-hearing group showed overall better response reliability, both within and between sessions, than the cochlear-loss group. These differences were small but consistent.