Lack of sleep can cause some of the same symptoms as depression -- extreme tiredness, loss of energy, and difficulty concentrating or making decisions. In addition, untreated depression may result in weight gain or loss, feelings of hopelessness and helplessness, and irritability.
Conflicts of national interest caused the World War II alliance between the United States and the Soviet Union to be replaced by a Cold War that lasted 45 years. Initially a dispute over the future of Europe, it grew to include confrontations around the world.
Some of the factors that brought about the end of the cold war are as follows: The world now has entered the post Cold War era. Many efforts have been made since the 1950s to promote relaxation of tensions and on many occasions in the past it appeared that the two power blocks had entered the period of detente. Gradually, however, the Cold War came to an end. This was due to the operation of several factors acting in tandem.