"Summary: A new closed-loop, acoustic stimulation technique significantly improves sleep quality and autonomic immune system function, and reduces symptoms of insomnia."
Article here...
neurosciencenews.com/ans-in...
The device is used in proprietary clinics and apparently there is one in London. Might be worth a try!
Contact for the London clinic is probably best on Facebook: facebook.com/CeresetLondon/
Insomnia 
Insomnia on Gabapentin.
Horizant and insomnia 
insomnia
