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.
Exxaro's Sipho Nkosi, worth nearly R2bn, was ranked 22nd, and his colleague Zweli Mntambo, worth R1.1bn, is ranked 30th. Saki Macozoma ranks 39th with investments worth R634m. Lazarus Zim is 68th with investments worth R419.6m in Sanlam and Northam Platinum.Robert Gumede ranks 82nd with his Gijima stake worth R334.4m.ana Marais. Rich still in pound seats. THE wealth of South Africa's 20 richest people, worth R134bn altogether, rose a mere 8% over the past year as the sluggish global economy weighed heavily on steel and mining share prices.