Global Epidemiology of Mental Disorders: What Are We Missing?

Background

Population-based studies provide the understanding of health-need required for effective public health policy and service-planning. Mental disorders are an important but, until recently, neglected agenda in global health. This paper reviews the coverage and limitations in global epidemiological data for mental disorders and suggests strategies to strengthen the data.

Methods

Systematic reviews were conducted for population-based epidemiological studies in mental disorders to inform new estimates for the global burden of disease study. Estimates of population coverage were calculated, adjusted for study parameters (age, gender and sampling frames) to quantify regional coverage.

Results

Of the 77,000 data sources identified, fewer than 1% could be used for deriving national estimates of prevalence, incidence, remission, and mortality in mental disorders. The two major limitations were (1) highly variable regional coverage, and (2) important methodological issues that prevented synthesis across studies, including the use of varying case definitions, the selection of samples not allowing generalization, lack of standardized indicators, and incomplete reporting. North America and Australasia had the most complete prevalence data for mental disorders while coverage was highly variable across Europe, Latin America, and Asia Pacific, and poor in other regions of Asia and Africa. Nationally-representative data for incidence, remission, and mortality were sparse across most of the world.

Discussion

Recent calls to action for global mental health were predicated on the high prevalence and disability of mental disorders. However, the global picture of disorders is inadequate for planning. Global data coverage is not commensurate with other important health problems, and for most of the world''s population, mental disorders are invisible and remain a low priority.     

Duplicate <Emphasis Type="Italic">dmbx1</Emphasis>genes regulate progenitor cell cycle and differentiation during zebrafish midbrain and retinal development

Background  

The Dmbx1 gene is important for the development of the midbrain and hindbrain, and mouse gene targeting experiments reveal that this gene is required for mediating postnatal and adult feeding behaviours. A single Dmbx1 gene exists in terrestrial vertebrate genomes, while teleost genomes have at least two paralogs. We compared the loss of function of the zebrafish dmbx1a and dmbx1b genes in order to gain insight into the molecular mechanism by which dmbx1 regulates neurogenesis, and to begin to understand why these duplicate genes have been retained in the zebrafish genome.     

The functional and numerical response of Typhlodromips swirskii (Acari: Phytoseiidae) to the factitious prey Suidasia medanensis (Acari: Suidasidae) in the context of a breeding sachet

The whitefly and thrips predator Typhlodromips swirskii (Athias-Henriot) (Acari: Phytoseiidae) can be reared on the factitious astigmatid mite Suidasia medanensis (Oudemans) (Acari: Suidasiidae). The predator–prey relationship allows the system to be incorporated into a breeding sachet which releases predators into a crop over several weeks ensuring predator presence on arrival of the target pests and increased predator numerical response on the crop through immigration from the breeding sachet. This study investigated whether the prey preference and functional and numerical response of T. swirskii to different development stages of S. medanensis can provide understanding of the predator–prey interactions sustaining such a breeding sachet. T. swirskii elicited a strong preference to egg stages of S. medanensis, exhibited a Type II functional response and increased oviposition rate with increasing prey density. The relevance of these attributes to a balanced breeding sachet is discussed.     

Genome-Wide Association Studies Identify Heavy Metal ATPase3 as the Primary Determinant of Natural Variation in Leaf Cadmium in Arabidopsis thaliana

Understanding the mechanism of cadmium (Cd) accumulation in plants is important to help reduce its potential toxicity to both plants and humans through dietary and environmental exposure. Here, we report on a study to uncover the genetic basis underlying natural variation in Cd accumulation in a world-wide collection of 349 wild collected Arabidopsis thaliana accessions. We identified a 4-fold variation (0.5-2 μg Cd g(-1) dry weight) in leaf Cd accumulation when these accessions were grown in a controlled common garden. By combining genome-wide association mapping, linkage mapping in an experimental F2 population, and transgenic complementation, we reveal that HMA3 is the sole major locus responsible for the variation in leaf Cd accumulation we observe in this diverse population of A. thaliana accessions. Analysis of the predicted amino acid sequence of HMA3 from 149 A. thaliana accessions reveals the existence of 10 major natural protein haplotypes. Association of these haplotypes with leaf Cd accumulation and genetics complementation experiments indicate that 5 of these haplotypes are active and 5 are inactive, and that elevated leaf Cd accumulation is associated with the reduced function of HMA3 caused by a nonsense mutation and polymorphisms that change two specific amino acids.     

Classification of the insulin-like growth factor binding proteins into three distinct categories according to their binding specificities

Competitive binding experiments with insulin-like growth factor (IGF)-1, IGF-2 and des-(1-3)-IGF-1 have confirmed the interpretation based on limited amino-terminal sequence analysis that at least three types of IGF binding protein occur. In addition to the acid stable subunit of the large serum binding protein which exhibits des-(1-3)-IGF-1 binding only slightly less than IGF-1, the small IGF binding proteins can be separated into two classes based on differences in des-(1-3)-IGF-1 and IGF-2 binding potencies.     

Stimulatory effect of gamma-aminobutyric acid upon animo acid incorporation into protein by a ribosomal system from immature rat brain

Abstract—

• 1 GABAstimulated the incorporation of L-[U-¹⁴C]leucine, primarily into the particulate protein of a ribosomal system from immature rat brain, but not from immature rat liver.
• 2 The GABA effect required the presence of Na⁺ and occurred at GABA concentrations which are thought to be physiological (1–5 mM).
• 3 Of all other amino acids tested at tissue extract concentrations in the system, only glycine had a similar effect. No analogues of GABA tested had a significant stimulatory effect upon leucine incorporation into protein, with the exception of homocarnosine which was mildly stimulatory.
• 4 The effect of GABA upon the incorporation of L-[U-¹⁴C]leucine was examined in the presence of added amino acid substrates, both individually and as mixtures. Also, the incorporation of L-[U-¹⁴C]leucine was compared with incorporation of L-[U-¹⁴C]Iysine and L-[U-¹⁴C]phenylalanine. The results are discussed in terms of GABA interaction with activating, transfer and transport mechanisms of other amino acids, inhibition of proteinase activity, and the possibility that GABA is stimulating the synthesis or turnover of specific proteins in the brain ribosomal system.
• 5 The results illustrate the fact that studies of ‘protein synthesis’ in immature rat brain ribosomes, as measured by amino acid incorporation, will yield answers which depend heavily upon substrate conditions and upon the labelled amino acid used as the marker for protein synthesis or turnover.

     

Developmental regulation of insulin-like growth factor-II/mannose 6-phosphate receptor mRNA in the rat.

This study examined levels of insulin-like growth factor-II/mannose 6-phosphate receptor (IGF-II/M6PR) mRNA in tissues of rats at different stages of growth. Northern blot analysis of total RNA from tissues of rats aged 2, 9, 21 and 42 days and from 21 day fetal rats was carried out using a cDNA probe to the IGF-II/M6PR. Northern blots showed this probe hybridized to a single 9kb band in all tissues tested. Highest hybridization signals were detected in fetal and neonatal tissues with levels rapidly decreasing after birth. For all age groups tested the highest signal was obtained with heart followed by muscle, lung, and kidney, with liver and brain showing lower levels of message. These results indicate that IGF-II/M6PR mRNA is developmentally regulated, and suggest a role for the IGF-II/M6PR in fetal and neonatal growth.