I have been using the Alpha-Stim SCS since last March and generally there has been a marked reduction in my anxiety levels, but over the past few months I feel as though the effect has decreased and its started creeping back.  I was wondering if maybe I am getting used to it or that the unit is not outputting the correct frequency or something?

I have noticed that I don't seem to get the 'tingling' as much as previously and some days I have it ramped up to 5 with no perceptible current through the ears.  Is there an easy way to check the output of the machine? 

Also, in the past if I ever used the machine to close to bed time my sleep would be restless - as expected, but now I can have it on late at night and fall asleep with no issues, which also makes me think that there is something wrong.

I am a user in the UK.  Thanks.