Depression Is the Leading Cause of Disability Around the World.

Potential Cause of Nodding Syndrome Identified Nodding syndrome, a rare form of epilepsy that has affected thousands of children between the ages of 5 and 15 years in East Africa, may be caused by an inappropriate immune reaction to the parasitic worm, Onchocerca volvulus, that causes onchocerciasis (river blindness), according to a report published in Science Translational Medicine. First documented in Tanzania in the 1960s, nodding syndrome has remained an untreatable disease characterized by seizures, neurological deterioration, and a high rate of death. Although the cause of nodding syndrome has been elusive, an increase in the condition in areas where the parasite O volvulus is endemic suggests that infection with the worm plays a role in disease pathogenesis. Using a protein chip method, investigators from the United States and Uganda analyzed serum specimens and cerebral spinal fluid (CSF) from children with nodding syndrome and from unaffected villagers (control group) in Uganda and South Sudan. They detected higher levels of autoantibodies to leiomodin-1—a protein normally found in neurons—in the serum samples and CSF of patients with nodding syndrome than in samples from the unaffected control subjects. They also showed that leiomodin-1 autoantibodies were toxic to human neurons grown in culture and that leimodin-1 is expressed in neurons in regions of the mouse brain that correspond to those affected in humans with nodding syndrome. Several O volvulus proteins are similar to leiomodin-1, and leimodin-1 autoantibodies isolated from patients with nodding syndrome cross-reacted with these homologous parasite proteins. These findings suggest that antibodies generated to fight the parasitic infection could inadvertently attack brain cells expressing leiomodin-1, causing an autoimmune reaction that gives rise to nodding syndrome. Although additional investigation is needed to further unravel the pathophysiology of the disease, these results suggest that patients with nodding syndrome may benefit from immunomodulatory therapies. Depression Is the Leading Cause of Disability Around the World The proportion of the global population living with depression is estimated to be 322 million people—4.4% of the world’s population— according to a new report, “Depression and Other Common Mental Disorders: Global Health Estimates,” released by the World Health Organization. The report also includes data on anxiety disorders, which affect more than 260 million people—3.6% of the global population. The prevalence of these common mental disorders is increasing, particularly in lowand middle-income countries, with many people experiencing both depressionandanxietydisorderssimultaneously. According to the report, the number of people in the world living with depression has increased by 18.4% between 2005 and 2015, and depressive disorders were the single largest contributor to nonfatal health loss globally in 2015. Although depression can affect anyone at any point in their lives, it is 1.5 times more common in women than men. Almost half the number of people living with depression reside in South-East Asia and Western Pacific regions. Poverty, unemployment, life events, and illness increase the risk of depression. The prevalence of anxiety disorders, which include generalized anxiety disorder, panic disorder, posttraumatic stress disorder, and obsessive-compulsive disorder, increased by 14.9% globally between 2005 and 2015 and was particularly high in the Americas. Anxiety disorders are now the sixth largest cause of disability and, as with depressive disorders, more women than men are affected.