First, I don't think people have the same operational definitions when speaking about attachment in the field of mental health. I use John Bowlby's Attachment Theory in early development and hook it Mary Ainsworth's Strange Experiment. "Attachment behavior in adults towards the child includes responding sensitively and appropriately to the child’s needs. Such behavior appears universally across cultures ( I have my doubts it's equal across cultures). Attachment theory provides an explanation of how the parent-child relationship emerges and influences subsequent development," (S. McCloud, 2009).

So yes, IMHO, if someone has experienced a safe and secure attachment they are better equipped to recover from the more difficult things in life. Though, it does not mean it is easy and painless for them to deal with all that comes their way. Not all of an infant's emotional needs can be met 100% of the time. "Bowlby (1958) proposed that attachment can be understood within an evolutionary context in that the caregiver provides safety and security for the infant. Attachment is adaptive as it enhances the infant’s chance of survival."

What I have noticed anecdotally is that most therapist are ill equipped, even if they think they can go the distance to deal with those that have the most needs. So, it is a risky undertaking for both therapist and client. If the therapist bails out the client falls father away from getting to be safely and securely attached. And, many people don't need that kind of therapy to heal. They already have the basic tools.

Good luck to you Brow Owl!

A good website to understand Attachment Theory:

Attachment Theory | Simply Psychology