Not sure what the time limit is, but the pundits on television say the difference between recession and depression depends mostly on the length of time it lasts.

             In the 1980s, for instance, the US went into a recession in 1981 and came back out in 1983. It went back into a recession again in 1984 and came out again a year or two later. They call this period a series of recessions, but it sure seemed like a depression to me.