Ecclesiastes 1:18
"For in much wisdom is much grief: and he that increaseth knowledge increaseth sorrow."
Cross References (ranked by relevance)
Job 28:28
14
And unto man he said, Behold, the fear of the LORD, that is wisdom; and to depart from evil is understanding.
Ecclesiastes 7:16
Be not righteous over much; neither make thyself over wise: why shouldest thou destroy thyself ?
Ecclesiastes 2:23
For all his days are sorrows, and his travail grief; yea, his heart taketh not rest in the night. This is also vanity.
Ecclesiastes 2:15
Then said I in my heart, As it happeneth to the fool, so it happeneth even to me; and why was I then more wise? Then I said in my heart, that this also is vanity.