Geophysical Variables and Behavior: Xcix. Reductions in Numbers of Neurons within the Parasolitary Nucleus in Rats Exposed Perinatally to a Magnetic Pattern Designed to Imitate Geomagnetic Continuous Pulsations: Implications for Sudden Infant Death

Correlational analyses have shown a moderate strength association between the occurrence of continuous pulsations, a type of geomagnetic activity within the 0.2-Hz to 5-Hz range, and the occurrence of Sudden Infant Deaths. In the present study, rats were exposed continuously from two days before birth to seven days after birth to 0.5-Hz pulsed-square wave magnetic fields whose intensities were within either the nanoTesla or microTesla range. The magnetic fields were generated in either an east-west (E-W) or north-south (N-S) direction. At 21 days of age, the area of the parasolitary nucleus (but not the solitary nucleus) was significantly smaller, and the numbers of neurons were significantly less in rats that had been exposed to the nanoT fields generated in the east-west direction or to the microTesla fields generated within either E-W or N-S direction relative to those exposed to the N-S nanoTesla fields. These results suggest nanoTesla magnetic fields, when applied in a specific direction, might interact with the local geomagnetic field to affect cell migration in structures within the brain stem that modulate vestibular-related arousal and respiratory or cardiovascular stability.

The impact of climate on risk of mania

Introduction

Bipolar disorder varies with season: admissions for depression peak in winter and mania peak in summer. Sunlight presumably increases the risk of mania through suppression of melatonin. If so, we expect admissions for mania to vary in accordance with climate variations.

Objectives

To investigate how climate and climate changes affects admissions for mania.

Aims

To identify which climate variables – sunshine, ultraviolet radiation, rain and snow cover – affect admissions for mania.

To examine whether year-to-year weather variation as well as long-term climate changes reflects the variation in number of admissions for mania.

Methods

This register-based nationwide cohort study covers all patients admitted for mania (ICD-10 code F31 or F30.0–F30.2) between 1995 and 2012 in Denmark. Climate data, obtained from the Danish Meteorological Institute, were merged with admission data and correlated using an Unobserved Component Model regression model.

Preliminary results

In total, 8893 patients were admitted 24,313 times between 1995 and 2012: 6573 first-admissions and 17,740 readmissions. Linear regression shows significant association between admissions per day and hours of sunshine (P < 0.01) and ultraviolet radiation (UV) dose (P < 0.01). Average days with snow cover and rain were not significantly correlated with admissions. Analyses on year-to-year variation and long-term change are not yet available.

Preliminary conclusions

Admissions for mania are correlated with sunshine and UV, but not rain and snow cover. If more patients are admitted during very sunny summers compared with less sunny summers this implies a relation with light itself and not just season.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Quantification of sodium pentobarbital residues from equine mortality compost piles

Sodium pentobarbital, a euthanasia drug, can persist in animal carcasses following euthanasia and can cause secondary toxicosis to animals that consume the remains. This experiment was conducted to observe the effects of composting on euthanized horse carcass degradation and sodium pentobarbital residues in compost material up to 367 d. Six separate compost bins were constructed on pastureland. Three bins served as the control while 3 served as the treatment. The carbonaceous material, or bulking agent, consisted of hardwood chips mixed with yard waste wetted to approximately 50% moisture content. Bulking agent was added to each bin at a depth of 0.46 m, creating the pad. A licensed veterinarian provided 6 horse carcasses for use in the experiment. These horses had required euthanasia for health reasons. All horses were weighed and then sedated with an intravenous injection of 8 mL of xylazine. After sedation the 3 horses in the treatment group were euthanized by intravenous injection of 60 mL of sodium pentobarbital. The 3 control group horses were anesthetized by intravenous injection of 15 mL of ketamine hydrochloride and then humanely euthanized by precise gunshot to the temporal lobe. Following euthanasia, each carcass was placed on the center of the pad and surrounded with 0.6 m of additional bulking agent. Serum and liver samples were obtained immediately following death. Compost samples were obtained on d 7, 14, 28, 56, 84, 129, 233, and 367 while soil samples were obtained on d -1 and 367. Each sample was analyzed for sodium pentobarbital concentration. Compost pile and ambient temperatures were also recorded. Composting successfully degraded soft tissue with only large bones remaining. Data illustrate that sodium pentobarbital was detectable up to 367 d in compost piles with no clear trend of concentration reduction. Drug residues were detected in soil samples indicating that sodium pentobarbital leached from the carcass and through the pad. These findings confirm the persistence of sodium pentobarbital from equine mortality compost piles and emphasize the importance of proper carcass management of animals euthanized with a barbiturate to reduce environmental impact and secondary toxicosis.

The 'disconnect' between initial judgments of lamotrigine vs. its real-world effectiveness in managing bipolar disorder. A tale with wider ramifications

OBJECTIVE

To detail the disconnect between the quantified efficacy of the mood stabilizer lamotrigine in its registration controlled trials and its later judged clinical effectiveness and consider some determinants of disconnects between some efficacy trial findings and 'real-world' clinical effectiveness judgments.

METHOD

Published articles considering lamotrigine as a treatment for the bipolar I or II disorders were selected for review. While randomized controlled trials were weighted, we also consider open trials and effectiveness observations from clinician researchers and demonstrate that lamotrigine has been quite variably judged over time.

RESULTS

We suggest that the early trials evaluating lamotrigine for acute bipolar disorder depression focused on a suboptimal clinical target, and in so doing, ensured less lamotrigine efficacy compared with trials of bipolar disorder preventative treatment. Moreover, a number of additional methodological limitations compromised analyses. We also detail variable reporting of actual study results. The initial sharp disconnect (between efficacy and effectiveness judgments) has narrowed as lamotrigine has been evaluated and progressively taken up as a maintenance mood stabilizer.

CONCLUSION

The lamotrigine disconnect story provides a number of salutary lessons that are salient to evaluating the effectiveness and ecological niche of any psychotropic medication. The lamotrigine story presented here argues strongly for the wisdom of encouraging an iterative process between efficacy studies and clinical observation.

The utility of a classificatory decision tree approach to assist clinical differentiation of melancholic and non-melancholic depression

BACKGROUND

Studies suggest that differentiating melancholic from non-melancholic depressive disorders is advanced by use of illness course as well as symptom variables but, in practice, potentially differentiating variables are generally positioned as having equal value. Judging that differentiating features are more likely to vary in their signal intensity, we sought to determine the number of features required to effect differentiation and their hierarchical order.

METHODS

The 24-item clinician-rated Sydney Melancholia Prototype Index (SMPI-CR) was completed for 364 unipolar depressed patients. The sample was divided into two cohorts according to the recruitment period. An RPART classification tree analysis identified the most discriminating SMPI items in the development sample of 197 patients, and examined the sensitivity and specificity of the diagnostic decisions, then sought to replicate findings in a validation sample of 169 patients.

RESULTS

Independent analyses of putative SMPI items identified only seven items as required to discriminate those with clinically-diagnosed melancholic or non-melancholic depression when the conditions were examined separately. An RPART analysis considering differentiation of melancholic and non-melancholic depression in the total samples retained five of those items in the classification tree, three of which were non-symptom items, and with 92% sensitivity and 80% specificity in the development sample. This reduced item set showed 93% sensitivity and 82% specificity in the validation sample.

LIMITATIONS

Our clinical judgment of melancholic or non-melancholic depression may not correspond with the clinical logic employed by other clinicians.

CONCLUSION

Only five SMPI items were required to derive a succinct and efficient decision tree, comprising high sensitivity and specificity in differentiating melancholic and non-melancholic depression. Current study findings provide an empirical model that could enrich clinicians׳ approach to differentiating melancholic and non-melancholic depression.

Differentiating 'clinical' and 'non-clinical' depression

OBJECTIVE

There has been increasing concern about extensions to the definition of 'clinical' depression, but little evident investigation as to how clinical and non-clinical depressive states might best be differentiated. This review considers the potential of many candidate symptom and non-symptom parameters.

METHOD

We overview representative concerns and theories about the nature of psychiatric disorders before reviewing the potential utility of candidate parameters for differentiating clinical and non-clinical depressive states.

RESULTS

While we detail limitations to all candidate parameters designed to distinguish between clinical and non-clinical depression, their actual utility may only be able to be judged by empirical testing across appropriate comparison groups.

CONCLUSION

We argue for initial comparisons being made between prototypically defined categorical (i.e. psychotic, melancholic and bipolar) depressive disease states and residual non-melancholic clinical depressive states, before considering how each of those two clinical subsets might differ from non-clinical depressive mood states.

Cleaving depressive diseases from depressive disorders and non-clinical states

OBJECTIVE

We sought to determine whether putative depressive diseases could be differentiated categorically from clinical depressive disorders and non-clinical mood states.

METHOD

We interviewed volunteers who reported or denied any lifetime depressive mood state and analyzed data from the former group reporting on their 'most severe' depressive episode. We employed latent class analysis (LCA) to determine whether a two-class solution was supported and the contribution of individual variables to class allocations.

RESULTS

All variables were significant predictors of class allocation. LCA-assigned Class I participants reported more depressive symptoms, had more distressing episodes and more lasting consequences, were more likely to view their depression as 'like a disease', and as being both disproportionately more severe and persistent in relation to any antecedent stressor. Validation involved comparison of LCA assignment with DSM-IV diagnosis for their most severe depressive episode. Of those assigned to Class I, 89% had a DSM diagnosis of melancholic, psychotic or bipolar depression. Class II had all those failing to meet criteria for a depressive episode and the majority of those with a non-melancholic depressive condition.

CONCLUSION

Despite not including individual depressive symptoms, study variables strongly differentiated putative depressive diseases from a composite of clinical depressive conditions and subclinical depressive states.

Is essential fatty acid status in late pregnancy predictive of post-natal depression?

OBJECTIVE

We tested the hypothesis that abnormal levels of omega-3 and omega-6 polyunsaturated fatty acids (PUFAs) during late pregnancy are associated with antenatal and post-natal depression.

METHOD

We interviewed a sample of more than 900 women in late pregnancy. We assessed whether they met criteria for depression on a standardized measure of post-natal depression [the Edinburgh Post-natal Depression Scale (EPDS)] and met DSM-IV criteria for major depression and/or were in receipt of antidepressant medication. Blood was collected at that time to generate data on nine PUFA variables. Sample members were re-interviewed post-natally to determine depressive experience in the 3 months following the birth of their baby.

RESULTS

Univariate associations were demonstrated between pre-natal depression categorized using DSM criteria and measures of blood fatty acids including total omega-3, the ratio of omega-6 to omega-3, docosahexaenoic acid (DHA) omega-3 and DHA plus eicosapentaenoic acid (EPA) omega-3. Such associations were not found post-natally, but different associations were quantified between EPDS-diagnosed depression and total omega-6, total omega-3 and EPA omega-3. In multivariate analyses, slight associations were maintained between EPDS and lower omega-3, lower EPA and higher omega-6 when neuroticism, stress during pregnancy, a lifetime episode of depression and older age were included in the analysis.

CONCLUSION

Findings in such a large sample indicate that PUFA status in late pregnancy is only slightly linked with the risk of post-natal depression when depression was quantified by the EPDS. There were no associations between post-natal depression diagnosed by DSM criteria and any fatty acid variables.

Computational hemodynamics analysis of intracranial aneurysms treated with flow diverters: correlation with clinical outcomes

BACKGROUND AND PURPOSE

Recent studies have shown promising results regarding intracranial aneurysms treated with flow diverters. However, these have had adverse effects, including delayed aneurysm occlusion, posttreatment symptoms, and rupture. The hemodynamic profiles of aneurysms treated with flow diverters were analyzed to determine the ones associated with successful and failed treatments.

MATERIALS AND METHODS

Patient-specific computational fluid dynamics were used to simulate hemodynamic profiles, including the presence of jet flow, energy loss, volume flow, and wall shear stress in 4 successful occlusions of aneurysms and 4 failed cases after flow-diverter deployment. In these 4 failed cases, hemodynamic profiles were examined again after a hypothetic second intervention. This involved replacing the failed flow diverter with a hypothetic optimally deployed flow diverter or simulated placement of a second flow diverter within the first (double hypothetic optimally deployed).

RESULTS

Where successful occlusions were achieved, a marked obliteration of jet flow was observed. Flow entering the aneurysm sac was diverted via the center of the flow diverter and joined smoothly with the continuation of flow leaving the aneurysm sac into the parent arteries. These observations were supplemented by a reduction in the other hemodynamic profiles. Aneurysm neck geometry might influence the efficacy of the flow diverter.

CONCLUSIONS

Hemodynamic indices, as calculated by using computational fluid dynamics techniques, have close correlation with flow-diverter treatment outcome. Computational fluid dynamics could be potentially useful as a planning tool for neurointerventionists by simulating an optimized flow-diverter deployment strategy before the procedure and evaluating posttreatment outcome.

The superiority of antidepressant medication to cognitive behavior therapy in melancholic depressed patients: a 12-week single-blind randomized study

OBJECTIVE

To pursue the previously long-standing but formally untested clinical view that melancholia is preferentially responsive to antidepressant medication in comparison with psychotherapy [specifically Cognitive Behavior Therapy (CBT)]. Second, to determine whether a broader action antidepressant medication sequencing regimen is superior to a Selective Serotonin Reuptake Inhibitor (SSRI) alone.

METHOD

We sought to recruit a large sample of participants with melancholic depression for a 12-week trial but inclusion criteria compromised recruitment and testing the second hypothesis. The first hypothesis was evaluated by comparing 18 participants receiving antidepressant medication to 11 receiving CBT. Primary study measures were the Hamilton Rating Scale for Depression (HAM-D) and the Hamilton Endogenous Subscale (HES), rated blindly, while several secondary measures also evaluated outcome.

RESULTS

Participants receiving medication had a superior 12-week outcome to those receiving CBT, with significant differences present on primary measures as early as 4 weeks. At trial conclusion, the percentage improvement in HAM-D scores was 61.1% vs. 34.4%, respectively [Number Needed to Treat (NNT) = 3.7] and with those in receipt of medication returning non-significantly higher HAM-D responder (66.6% vs. 36.4%, NNT = 2.8) and remission (66.7% vs. 45.4%, NNT = 4.7) rates.

CONCLUSION

As the sample size was small and participants evidenced only moderate levels of depression severity, the study risked being underpowered and idiosyncratic. Despite the small sample, the superiority of antidepressant medication to CBT in those with a melancholic depression was distinctive in this pilot study.