Effects of methamphetamine abuse and serotonin transporter gene variants on aggression and emotion-processing neurocircuitry.

Individuals who abuse methamphetamine (MA) exhibit heightened aggression, but the neurobiological underpinnings are poorly understood. As variability in the serotonin transporter (SERT) gene can influence aggression, this study assessed possible contributions of this gene to MA-related aggression. In all, 53 MA-dependent and 47 control participants provided self-reports of aggression, and underwent functional magnetic resonance imaging while viewing pictures of faces. Participants were genotyped at two functional polymorphic loci in the SERT gene: the SERT-linked polymorphic region (SERT-LPR) and the intron 2 variable number tandem repeat polymorphism (STin2 VNTR); participants were then classified as having high or low risk for aggression according to individual SERT risk allele combinations. Comparison of SERT risk allele loads between groups showed no difference between MA-dependent and control participants. Comparison of self-report scores showed greater aggression in MA-dependent than control participants, and in high genetic risk than low-risk participants. Signal change in the amygdala was lower in high genetic risk than low-risk participants, but showed no main effect of MA abuse; however, signal change correlated negatively with MA use measures. Whole-brain differences in activation were observed between MA-dependent and control groups in the occipital and prefrontal cortex, and between genetic high- and low-risk groups in the occipital, fusiform, supramarginal and prefrontal cortex, with effects overlapping in a small region in the right ventrolateral prefrontal cortex. The findings suggest that the investigated SERT risk allele loads are comparable between MA-dependent and healthy individuals, and that MA and genetic risk influence aggression independently, with minimal overlap in associated neural substrates

Gray-matter volume, midbrain dopamine D2/D3 receptors and drug craving in methamphetamine users.

Dysfunction of the mesocorticolimbic system has a critical role in clinical features of addiction. Despite evidence suggesting that midbrain dopamine receptors influence amphetamine-induced dopamine release and that dopamine is involved in methamphetamine-induced neurotoxicity, associations between dopamine receptors and gray-matter volume have been unexplored in methamphetamine users. Here we used magnetic resonance imaging and [(18)F]fallypride positron emission tomography, respectively, to measure gray-matter volume (in 58 methamphetamine users) and dopamine D2/D3 receptor availability (binding potential relative to nondisplaceable uptake of the radiotracer, BPnd) (in 31 methamphetamine users and 37 control participants). Relationships between these measures and self-reported drug craving were examined. Although no difference in midbrain D2/D3 BPnd was detected between methamphetamine and control groups, midbrain D2/D3 BPnd was positively correlated with gray-matter volume in the striatum, prefrontal cortex, insula, hippocampus and temporal cortex in methamphetamine users, but not in control participants (group-by-midbrain D2/D3 BPnd interaction, P<0.05 corrected for multiple comparisons). Craving for methamphetamine was negatively associated with gray-matter volume in the insula, prefrontal cortex, amygdala, temporal cortex, occipital cortex, cerebellum and thalamus (P<0.05 corrected for multiple comparisons). A relationship between midbrain D2/D3 BPnd and methamphetamine craving was not detected. Lower midbrain D2/D3 BPnd may increase vulnerability to deficits in gray-matter volume in mesocorticolimbic circuitry in methamphetamine users, possibly reflecting greater dopamine-induced toxicity. Identifying factors that influence prefrontal and limbic volume, such as midbrain BPnd, may be important for understanding the basis of drug craving, a key factor in the maintenance of substance-use disorders

Marriage as a Rat Race: Noisy Pre-Marital Investments with Assortative Matching

We study the incentive to invest to improve marriage prospects, in a frictionless marriage market with non-transferable utility. Stochastic returns to investment eliminate the multiplicity of equilibria in models with deterministic returns, and a unique equilibrium exists under reasonable conditions. Equilibrium investment is efficient when the sexes are symmetric. However, when there is any asymmetry, including an unbalanced sex ratio, investments are generically excessive. For example, if there is an excess of boys, then there is parental over-investment in boys and under-investment in girls, and total investment will be excessive.marriage, ex ante investments, gender differences, assortative matching tournament, sex ratio

Striatal dopamine D1-type receptor availability: no difference from control but association with cortical thickness in methamphetamine users.

Chronic methamphetamine use poses potentially devastating consequences for directly affected individuals and for society. Lower dopamine D2-type receptor availability has been observed in striata of methamphetamine users as compared with controls, but an analogous comparison of D1-type receptors has been conducted only on post-mortem material, with no differences in methamphetamine users from controls in the caudate nucleus and putamen and higher D1-receptor density in the nucleus accumbens. Released from neurons when methamphetamine is self-administered, dopamine binds to both D1- and D2-type receptors in the striatum, with downstream effects on cortical activity. Thus, both receptor subtypes may contribute to methamphetamine-induced alterations in cortical morphology and behavior. In this study, 21 methamphetamine-dependent subjects and 23 healthy controls participated in positron emission tomography and structural magnetic resonance imaging for assessment of striatal D1- and D2-type receptor availability and cortical gray-matter thickness, respectively. Although D2-type receptor availability (BPnd) was lower in the methamphetamine group, as shown previously, the groups did not differ in D1-type BPnd. In the methamphetamine group, mean cortical gray-matter thickness was negatively associated with cumulative methamphetamine use and craving for the drug. Striatal D1-type but not D2-type BPnd was negatively associated with global mean cortical gray-matter thickness in the methamphetamine group, but no association was found between gray-matter thickness and BPnd for either dopamine receptor subtype in the control group. These results suggest a role of striatal D1-type receptors in cortical adaptation to chronic methamphetamine use

The European economy in 1999 and 2000: Report

World economic growth this year is likely to remain as weak as in 1998, despite a gradual acceleration in the course of the year. The volume of world trade is estimated to have fallen significantly in the latter half of last year, and to date there are few signs of a rapid recovery. However, there are indications of improved investor sentiment in a number of emerging market economies, and the monetary authorities in many industrial economies have lowered shortterm interest rates significantly since last autumn. In the absence of further financial market turmoil, a modest global recovery is expected to develop this year, led by improved prospects for the Asian economies. World GDP is expected to rise by 3 per cent in 2000, after growth of 2V4 per cent this year (Table 1). The industrial economies as a group are not expected to contribute significantly to the overall rebound. The economy of the United States has remained much stronger than expected, but could experience a soft landing next year, particularly if the Federal Reserve decides to tighten monetary policy. Activity in Japan may at best stabilise next year after two years of declining GDP, with many firms continuing to have excess capacity, and domestic demand expected to remain weak. The continuing weakness of Japan will help to keep the upturn in the emerging markets within bounds. Growth should pick up in Western Europe over the next eighteen months, helped by the present relaxed monetary conditions. However, a recovery this year remains far from assured, with activity likely to be particularly weak in Germany and Italy. The present, historically low, rate of inflation in the industrial world may rise slightly, partly as a result of some recovery in world prices for primary commodities, recently in particular for oil. In the euro area, import prices will also rise as a result of the recent depreciation of the euro against the dollar. The continued strength of the dollar can be partly attributed to the very strong performance of the American economy compared with the European economy, and to the rising interest rate differentials with Europe. We expect that developments in the opposite direction will weaken the dollar again. Section VI of this report illustrates a scenario with a more substantial weakening in the aftermath of a collapse in equity prices. The Western European economy has been strongly affected by the adverse developments in the crisis regions. This has depressed industrial production significantly over the past year. The prospects for Europe are heavily dependent on the timing and extent to which these effects fade away. The American economy has been a strong engine for world economic growth up to now, but there are several imbalances that may lead to a slowdown over the next eighteen months. This could have a substantial impact on the European economy. --

The European economy in 1998 and 1999

World economic activity remains relatively robust, although the Asian crisis casts a shadow over the picture. The rate of growth of world trade has slowed down since last fall, but is expected to remain above its trend level. International price developments remain quite moderate. Oil prices have declined substantially, and are among the lowest of the decade. Inflationary pressures are also limited in the industrial countries, as capacity constraints are not yet significant there and excess supply has materialized worldwide. The industrial countries show a sustained growth rate between 2Vi and 3 per cent on average. However, the combination of strong growth and low inflation is the result of divergent developments between countries. • The US economy has been until recently particularly buoyant, as strong domestic demand has more than offset the dampening effect of falling exports to Asia. The Japanese economy remains in the doldrums. The threat of a deflation has recently prompted a substantial stimulation programme aiming at preventing a further deterioration of confidence. \^ Economic growth in Asia has been-severely_ restricted, in particular in the ASEAN countries and Korea, although extensive rescue operations have brought the situation in the worst hit countries more or less under control. The impact on the European countries is as yet rather limited, as negative trade effects are largely compensated for by beneficial effects of lower imported inflation and lower interest rates. Thus Western Europe is in a position to sustain the recovery that began in mid-1996. Prospects have been strengthened as uncertainties associated with the implementation of the EMU have now been dissipated. The time has now come to begin to view the EMU countries as a single entity from the viewpoint of economic management, even if differences persist in many fields. --

The European economy in 1998 and 1999: An update

A. Situation and Prospects for the European Economy 3 I. Slower Growth of the World Economy 3 II. Weaker Expansion of the European Economy 5 III. Economic Policy 7 B. Country Reports 9 I. Germany: Upturn Continues Despite Financial Turbulence 9 II. Confidence Still High in France, Though Off Its Peak 9 III. Downturn in the UK Economy 10 IV. Italy: A Fragile Recovery 11 --

Levothyroxine effects on depressive symptoms and limbic glucose metabolism in bipolar disorder: a randomized, placebo-controlled positron emission tomography study.

Adding supraphysiologic doses of levothyroxine (L-T4) to standard treatment for bipolar depression shows promise, but the mechanisms underlying clinical improvement are unknown. In a previous pilot study, L-T4 treatment reduced depression scores and activity within the anterior limbic network. Here we extended this work in a randomized, double-blind, placebo-controlled study of patients with bipolar depression. Cerebral glucose metabolism was assessed with positron emission tomography and [F-18]fluorodeoxyglucose before and after 6 weeks of treatment with L-T4 (n=15) or placebo (n=10) in 12 volumes of interest (VOIs): the bilateral thalamus, amygdala, hippocampus, dorsal striatum and ventral striatum, and midline cerebellar vermis and subgenual cingulate cortex. Radioactivity in the VOIs, normalized to whole-brain radioactivity was taken as a surrogate index of glucose metabolism, and markers of thyroid function were assayed. Changes in brain activity and their association with clinical response were assessed using statistical parametric mapping. Adjunctive L-T4 treatment produced a significant decline in depression scores during the 6-week treatment. In patients treated with L-T4, we found a significant decrease in regional activity at P<0.05 after Bonferroni correction in the left thalamus, right amygdala, right hippocampus, left ventral striatum and the right dorsal striatum. Decreases in the left thalamus, left dorsal striatum and the subgenual cingulate were correlated with a reduction in depression scores (P<0.05 after Bonferroni correction). Placebo treatment was associated with a significant decrease in activity only in the right amygdala, and no region had a change in activity that was correlated with change in depression scores. The groups differed significantly in the relationship between the changes in depression scores and in activity in the thalamus bilaterally and the left ventral striatum. The findings provide evidence that administration of supraphysiologic thyroid hormone improves depressive symptoms in patients with bipolar disorder by modulating function in components of the anterior limbic network

Recess in the 21st Century Post-COVID World

The abrupt onset of the COVID-19 pandemic forced the world into frenzied action, creating a series of ongoing stressors: school/work closings, remote learning, canceled events, family strife, fear, and a significant loss of social interactions. It is now unsurprising to learn that children's mental health has suffered. As social connection is tightly entwined with children's mental health, supporting school-based spaces for quality social interactions is an important post-pandemic recovery strategy. The unstructured school recess space is ideal for supporting recovery. A large and growing body of evidence supports the important role of recess, yet evidence also suggests that recess is not always implemented in ways that fulfill its promise