There may be no single cause of bipolar disorder (aka manic depression). Instead, research indicates the causes of bipolar disorder are probably a combination of biochemical, genetic and environmental factors that may trigger and perpetuate the chemical imbalances in the brain.
Net worth: $829 million. Telecommunications mogul Strive Masiyiwa is widely regarded as the richest man in Zimbabwe and is one of the richest men in Africa with a net worth of more than US$800 million.
Meet The 32 Year-Old Entrepreneur Who Is Building Zimbabwe's Largest Solar Company Simbarashe Mhuriro, 32, is the founder and Managing Director of Oxygen Energy Private Limited, an independent power producer and renewable energy development company that specialises in utility scale power plants and commercial rooftop projects.