In rare cases, anxiety, aggression and depression may also occur.

Having been depressed before, especially if depression first occurred at an early age.

Minor depression occurs in up to 30% of patients following stroke.

The only reason a depression might not occur in 1990, he says, is if enough people heed his warning.

He concludes that because no depression occurred in the 1960's, one is all but certain, starting in 1990.

So when depression does occur, it is an illness that must be treated.

But depression can also occur if you have no family history of the illness.

However, depression can also occur in people with no family history of depression.

If your depression occurs in the fall or winter months, try light therapy using a special lamp that is like sunlight.

In extreme cases, he said, respiratory depression and death can occur.