In a book by Ann France describing her therapy experience (Consuming Psychotherapy) she makes the following statements: “I am now not at all sure that vulnerable people should be exposed to psychotherapy. This implies that … most of those who need it may not be sufficiently resilient to benefit from it, given the strain it actually causes … psychotherapy … can be harmful, without there being any very clear way of knowing in advance whether this will happen … It can merely be the replay of past traumata … which leads to nothing … The dangers in such a perilous undertaking … provided the genesis of this book … it works best with the healthy”.

The quote comes from this guy who did not have a great experience with a therapist.
Therapy Consumer Guide - A Recent Experience in Psychotherapy