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.
In 1966 Hughes became one of the richest men in the world when he was forced to sell his shares in TWA making him $547 million. In the same year Hughes and Peters moved to Las Vegas, although by this time, due to Hughesâ phobias, they tended to communicate by notes rather than by meeting.