The story of the moment: risk averse cypriot farmers respond to drought management

This article illustrates the importance of estimating risk preferences when evaluating water policy. Using agricultural production data from the Kiti region of Cyprus we estimate farmers' risk preferences a la Antle (Journal of Business and Economic Statistics, 1, 192-201, 1983, American Journal of Agricultural Economics, 69, 509-22, 1987) and show sensitivity to higher order moments of profit, such as skewness. We show that farmers in the Kiti region are risk averse with risk premiums in the region of 20% of expected profit. We use these estimates to analyse the impact of a water quota from the perspective of three policy-makers who differ only in their understanding of farmers' risk preferences. We show in the case of Kiti that policy-makers who model risk preferences incorrectly, that is, either; (a) assume risk neutrality or; (b) ignore down-side risk, wrongly predict the magnitude and direction of input responses and therefore the magnitude of welfare changes. This highlights the importance of accommodating preferences for higher order moments of profit in the evaluation of water policy.

Elevated brain serotonin turnover in patients with depression

Context: The biological basis for the development of major depressive disorder (MDD) remains incompletely understood. Objective: To quantify brain serotonin (5-hydroxytryptamine [5-HT]) turnover in patients with MDD. Design: Patients with depression were studied both untreated and during administration of a selective serotonin reuptake inhibitor (SSRI) in an unblinded study of sequential design. Healthy volunteers were examined on only 1 occasion. Direct internal jugular venous blood sampling was used to directly quantify brain serotonin turnover. The effect of serotonin transporter (5-HTT) genotype on brain serotonin turnover was evaluated and the influence of SSRI therapy on serotonin turnover was investigated. Setting: Participants were recruited from the general community following media advertisement. Experimental procedures were performed in the research catheterization laboratory of a major training hospital and medical research institute. Participants: Studies were performed in 21 patients fulfilling the DSM-IV and International Statistical Classification of Diseases, 10th Revision diagnostic criteria forMDD and in 40 healthy volunteers. Interventions: Treatment for patients consisted of SSRI administration for approximately 12 weeks. Main Outcome Measures: Brain serotonin turnover before and after SSRI therapy. Results: Brain serotonin turnover was significantly elevated in unmedicated patients withMDDcompared with healthy subjects (mean [SD] internal jugular venoarterial 5-hydroxyindoleacetic acid plasma concentration difference, 4.4 [4.3] vs 1.6 [2.4] nmol/L, respectively; P=.003). Analysis of the influence of the 5-HTT genotype in MDD indicated that carriage of the s allele compared with the l allele was associated with greater than a 2-fold increase in brain serotonin turnover (mean [SD] internal jugular venoarterial 5-hydroxyindoleacetic acid plasma concentration difference, 6.5 [4.7] vs 2.7 [2.9] nmol/L, respectively; P=.04). Following SSRI therapy, brain serotonin turnover was substantially reduced (mean [SD] internal jugular venoarterial 5-hydroxyindoleacetic acid plasma concentration difference, 6.0 [4.0] nmol/L prior to treatment vs 2.0 [3.3] nmol/L following therapy; P=.008). Conclusions: Brain serotonin turnover is elevated in unmedicated patients with MDD and is influenced by the 5-HTT genotype. The marked reduction in serotonin turnover following SSRI treatment and the accompanying improvement in symptoms suggest that high brain serotonin turnover may be a biological substrate of MDD

Increased brain serotonin turnover in panic disorder patients in the absence of a panic attack: Reduction by a selective serotonin reuptake inhibitor

Since the brain neurotransmitter changes characterising panic disorder remain uncertain, we quantified brain noradrenaline and serotonin turnover in patients with panic disorder, in the absence of a panic attack. Thirty-four untreated patients with panic disorder and 24 matched healthy volunteers were studied. A novel method utilising internal jugular venous sampling, with thermodilution measurement of jugular blood flow, was used to directly quantify brain monoamine turnover, by measuring the overflow of noradrenaline and serotonin metabolites from the brain. Radiographic depiction of brain venous sinuses allowed differential venous sampling from cortical and subcortical regions. The relation of brain serotonin turnover to serotonin transporter genotype and panic disorder severity were evaluated, and the influence of an SSRI drug, citalopram, on serotonin turnover investigated. Brain noradrenaline turnover in panic disorder patients was similar to that in healthy subjects. In contrast, brain serotonin turnover, estimated from jugular venous overflow of the metabolite, 5-hydroxyindole acetic acid, was increased approximately 4-fold in subcortical brain regions and in the cerebral cortex (P < 0.01). Serotonin turnover was highest in patients with the most severe disease, was unrelated to serotonin transporter genotype, and was reduced by citalopram (P < 0.01). Normal brain noradrenaline turnover in panic disorder patients argues against primary importance of the locus coeruleus in this condition. The marked increase in serotonin turnover, in the absence of a panic attack, possibly represents an important underlying neurotransmitter substrate for the disorder, although this point remains uncertain. Support for this interpretation comes from the direct relationship which existed between serotonin turnover and illness severity, and the finding that SSRI administration reduced serotonin turnover. Serotonin transporter genotyping suggested that increased whole brain serotonin turnover most likely derived not from impaired serotonin reuptake, but from increased firing in serotonergic midbrain raphe neurons projecting to both subcortical brain regions and the cerebral cortex