As a long-term reference
The strongest case. If you expect to use this the way people use a manual — opening it when a specific situation arises, for years — the binding is the part that matters.
Worth the difference in one specific case: when this is a book you expect to still be opening in three years.
The honest comparison, including where hardcover is the worse choice.
Carrying every day in a bag
Staying open on a desk without being held
Cost
Surviving several years of repeated opening
Not minding when it gets worn
Keeping a copy that still looks intact
Writing heavily throughout
Occasional marking on paper that takes ink well
Buying two copies, one to lend
Being the copy that stays on the shelf and gets returned to
All reasonable, and quite different from each other.
The strongest case. If you expect to use this the way people use a manual — opening it when a specific situation arises, for years — the binding is the part that matters.
Hardcovers hold their position on a flat surface. If you work through exercises at a desk with a notebook, this is a genuine daily convenience rather than a small one.
The edition that reads as a considered present. Whether a book about mental health is the right gift is a separate question, covered on the FAQ page about giving it.
Answered including the case for not buying it.
No. Identical text across all editions. You are buying binding and paper, not more material.
Probably not. The paperback contains everything, and library lending contains everything for nothing. Buy the cheapest edition you will actually use — that decision has no effect on what you get out of it.
Yes, and it stays open better than paperback. Some people are more reluctant to write in a hardcover, which is worth noticing about yourself before choosing — an unmarked book you were protecting is not a working copy.
Better than paperback structurally, though it is heavier and the corners are more prone to visible damage. For daily transport, paperback is usually the more sensible choice.
If a book about their mental health is something they have asked for, yes — it is the edition that presents well. If they have not asked, the FAQ page on giving it is worth reading first.
There is a quiet tension in buying the durable edition of a practical book. Hardcover suggests permanence and care, which is exactly the attitude that can stop you writing in it. People who buy the nice edition sometimes end up protecting it, and a protected copy of a working book is doing considerably less than a battered one.
So the useful question is not which edition is better made. It is which one you will treat as a tool. If a clean hardcover would make you hesitate before putting a pen through a paragraph, the paperback is the better purchase regardless of build quality.
Where hardcover genuinely earns its price is the long-reference case. If you expect to open this at a specific page in year three, during a difficult week, the binding is what determines whether that is still pleasant to do.
And if you are choosing between spending more on this and buying nothing because of the price, buy the cheapest edition available or borrow it. Nothing in the book requires ownership of a good copy.
The best copy of a working book is usually the scruffy one.