Vit. B12 (lack thereof) is related to high cortisol levels. It can be depleted by childbirth, anasthesia, laughing gas, high stress… Insufficient B12 can lead to brain issues such as OCD and even psychosis. Some people cannot properly absorb B12 due to an intrinsic factor problem in thier stomach – therefore B12 shots or sublingual tablets are available. Magnesium and D3 might have also played roles in helping me eliminate my torturous song snippets. Please read the book “Could it be B12” I’m quite free of the snippets now. Never tried any SSRI’s or pharma type drugs.