Sentence:  It's only right that the tide of inspirational books should yield to the occasional <WSD>depressional</WSD> one &mdash; for every humorist, a dishumorist, a man who runs his nails down the blackboard and makes everyone's hair stand up, though we humorists would note that you have to work hard to get a laugh and that dishumor is tyrannical: you need only say out loud, “How can you people stand around here and enjoy yourselves while the world is falling apart?” and all conversation ends. 
Meaning of the word marked with <WSD> tags:  Of or pertaining to psychological depression.