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.
Country: South Africa. South Africaâs richest black man, Patrice Motsepe has a fortune of about $2.9 billions. He started learning business lessons from his father who was a small time businessman in South Africa. He founded a mining company which is African Rainbow Minerals (ARM) and he is the chairman of it.