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.
Zimbabwe is unusual in Africa in that there are a number of ancient ruined cities built in a unique dry stone style. The most famous of these are the Great Zimbabwe ruins in Masvingo. Other ruins include Khami Ruins, Zimbabwe, Dhlo-Dhlo and Naletale, although none of these is as famous as Great Zimbabwe.resident Robert Mugabe serves as head of state and government, and as commander-in-chief of the armed forces. Renowned as a champion for the anticolonial cause, Mugabe also has a reputation as an authoritarian figure responsible for Zimbabwe's problematic human rights record and substantial economic decline.