Takes a very broad view of self-help that also encompasses traditionally male improvement-oriented subgenres like pop science and business. The actual evidence for the efficacy of bibliotherapy doesn't come until after a longish canned history of the genre.

My takeaway from this article is that it helps some people sometimes. 

Depends on the person and situation.

Often what you get out of it is what you put into it.

At least there aren't physical side effects, like with medication; and it's pretty cheap, unlike therapy.

And in the best cases it offers encouragement to start improving and then keep improving. 

Best part of the article to me:

Once a particular book meets basic effectiveness benchmarks, the final verdict is more dependent on each seeker’s unique sensibilities. Self-help’s empirical shift has been a boon: readers can now proceed with more confidence that the end results will be worth the effort invested. But this shift has also given rise to many books that aim to help readers solve specific, bounded problems (depression, pessimism, relational conflict, social anxiety) rather than offering broader insights about how to live. Decades ago, when educated people regarded psychotherapy as a basic tool for carving out a fulfilled existence, it was only natural that self-help books such as Harris’s and Peck’s tracked the zeitgeist, guiding people to achieve the deep-rooted life satisfaction Aristotle called eudaimonia. Nowadays, therapy tends to focus more on healing well-defined mental pathology, and much recent self-help literature does the same.

Still, through all these changes in intellectual fashion, our desire for eudaimonia remains as strong as ever. In his writings, Norcross has pegged the self-help movement as part of the ‘human quest to understand and conquer behavioural disorders’, but many readers would find that description incomplete. When we pore endlessly over self-help titles, most of us aren’t just looking to resolve our problems one by one, with a to-do list mentality. We’re groping for something more profound – to infuse our plodding lives with new texture and meaning.

That’s why the psychologist Susan Krauss Whitbourne at the University of Massachusetts thinks it’s important to approach each self-help title with subjective attention to whether the content resonates on a deep level. ‘You want to look at: Is this something that’s going to work? What do I see in there that relates to me personally?’ It’s that sense of connection with a book, Whitbourne believes, that lets readers forge a therapeutic alliance with the author, boosting the odds that a literary meeting of the minds will spur genuine change.

Having dipped into self-help books with a strong empirical bent, I can attest that the benefits are real. I’m convinced that Feeling Good, with its well-vetted techniques to combat negative thinking, helped lift me out of a stubborn bout of depression. As someone prone to descend into spirals of dark thought, I also benefited from the advice of Burns’ colleague, psychiatrist Aaron Beck, who recommends keeping a ‘Daily Record of Dysfunctional Thoughts’. Writing down my exaggerated thoughts, identifying the errors they contained, and rebutting them with more logical thoughts helped keep my problems in perspective. The thought-challenging exercises reinforced a critical truth – I didn’t have to buy into everything my sometimes-overheated brain was telling me. My book-inspired course of self-therapy, I now believe, helped me as much as my sessions with a psychologist.