It's a general rule in the UK. If it makes you feel good, it's illegal. So I wouldn't hold out much hope on a legal substance being that helpful. Although I hope it does work for you.
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Prof-Diagnosed: Aspergers Syndrome (I still call it that!), Dyspraxia, Dysgraphia
Self-diagnosed: ADHD-PI, Social Anxiety, Depression
Treatment: 5-HTP, Ginkgo Biloba, Omega-3, Pro-Biotics, Multi Vitamin, Magnesium