When I see this card in a spread, I know something has happened to cause the seeker worry to the point of despair. Classically, this card represents pressing angst that keeps you up at night. It can indicate dreams caused by stress.
Swords are all about thinking, pondering, and analyzing. This card can indicate an immense amount of time being taken analyzing problems and worrying about impending doom bringing the seeker to a very depressed state. It is also likely that these problems and worry about them has been going on for a good amount of time. The seeker may feel powerless to improve this situation.
The surrounding cards always tell the story. When the seeker is surrounded by Cups, this card indicates worry over love, relationships, and emotional ties—Wands can indicate problems at work or creative block, and Pentacles, money. Paired with a reversed Star card, this could be serious long-lasting depression that requires the help of a professional.
Always a relief, the 9 of Swords reversed means that troubled waters have passed. There has been a recovery and the seeker can move forward confidently. It’s a sigh of relief a long time coming.