Harlequin is by far my favourite strain and it does indeed get you high - it's just a different kind of high, and for most people it does not cause any paranoia and helps with anxiety.
The ratio of CBD to THC for Harlequin is on average 5:2, so it does contain THC, the CBD just balances it out a bit to make the high more mellow. Some phenotypes (variations) of Harlequin however have up to 1:1 CBD to THC (they get you more high).
There are also "pure" CBD strains out there (and ones that have so much more CBD than THC that it does not get you high) - for these look at Charlotte's Web or AC/DC.
But in my personal experience, CBD itself does very little "active" helping in terms of mental issues, such as anxiety - for that you need a bit more THC, such as what Harlequin provides but YMMV.
Mustafa's previous Harlequin batches have been quite good, but they lean more towards the 1:1 ratio rather than the 5:2 ratio - they get me more "high" than the Harlequin I grow myself.
I'd still recommend it though - it's still a very smooth high overall (I sometimes prefer it).
I've also found that the high from Harlequin is smoother when vaping vs when smoking (unless you use a bong of some kind).
Also, Harlequin is a VERY easy strain to grow, so if you find it helpful, I'd recommend getting some seeds and just growing your own