The most common and most likely answer to this crossword clue is the 10 letter word PSYCHOLOGY
I've seen this crossword clue in The Guardian
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More clues leading to the result PSYCHOLOGY
Buddy explains!

The straight part
We know that "mind study" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case mind study = psychology.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 PSYCHOLOGY mean?
PSYCHOLOGY noun- The study of the human mind.
- The study of human behavior.
- The study of animal behavior.
- The mental, emotional, and behavioral characteristics pertaining to a specified person, group, or activity.