Hypnotherapy stands as a controversial yet intriguing method of psychological treatment. As explored in my novel "Forgotten Dark," this practice can be both a beacon of hope and a Pandora's box of hidden terrors.

Proponents of hypnotherapy tout its potential benefits including stress reduction, pain management and behaviour modification

However, like the protagonist Sally, some patients discover that delving into the subconscious is not without risks including false memories, emotional trauma and dependence.

Here's a list of psychological suspense or thriller novels with themes of hypnotherapy or memory loss:

1. "The Memory Box" by Sam Blake 
2. "The House of Second Chances" by Esther Campion 
3. "Before I Go To Sleep" by S.J. Watson 
4. "I Let You Go" by Clare Mackintosh 
5. "The Silent Patient" by Alex Michaelides 
6. "The Escape Room" by Megan Goldin 

As "Forgotten Dark" chillingly illustrates, the human mind is a complex landscape. While hypnotherapy offers tantalizing possibilities for healing and self-discovery, it also carries the risk of unearthing truths better left buried in the labyrinth of their own minds. Either way, it makes for great psychological fiction!