You raise some excellent points about these complex issues. Therapists are like every other profession, such as engineers or nurses, there are some superb practitioners, a large group that do decent work, and a small group that are actually toxic. That is why I recommend that people try two or three therapists, so that they find one who is a good fit for them. The process of measuring also increases the likelihood of progress, but it is not a guarantee. Therapists cannot help everyone all the time, and I am very aware that there are many factors in my clients’ lives that contribute to, or degrade, their emotional well being. The degree to which excellent therapy can lengthen people’s lifespans is one that I wish was vigorously researched. I could only find a few research studies, but this topic is of enormous importance. The epigenetic changes are not deletions from the chromosome, but are additions or deletions of methyl groups. The telomeres shorten with stress, but it is of enormous importance to research if we can lengthen them again (or greatly decelerate the shortening) and contribute to people’s lifespan.