I read the following interesting excerpt from a book entitled Return Again, The Dynamics of Reincarnation by Rabbi Avraham Arieh Trugman.
...[the Talmud teaches] that the Mashiach will not arrive before all the souls "leave the body," the heavenly treasury of souls. As we approach the year 6,000...the process of emptying the body of souls has dramatically accelerated. In the last two hundred years the world's population has increased at an astonishing rate. This is a result of the world being readied for the Messianic era. The implication of this is astounding - all the souls who have ever incarnated at different times of history and in all sorts of different soul combinations are all coming together on earth at the same time. This is one of the reasons life appears to be so complex in contemporary times, as there is simply an overload of psychic, emotional and spiritual energy in need of processing. Different parts of our soul histories are all returning at the same time in an increasingly interconnected physical and spiritual global village.