The most common and most likely answer to this crossword clue is the 8 letter word MISERIES
I've seen this crossword clue in The Times
M
I
S
E
R
I
E
S
More clues leading to the result MISERIES
Buddy explains!

The straight part
We know that "Sad people" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case sad people = miseries.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does MISERIES mean?
MISERIES noun- Great unhappiness; extreme pain of body or mind; wretchedness; distress; woe.
- A bodily ache or pain.
- Cause of misery; calamity; misfortune.
- (Extreme) poverty.
- Greed; avarice.