The Pottergate Centre offers free screening evaluations for the DES 2, SQD-20, and A-DES (the adolescent version of the DES) for those in the appropriate age group.
They actually score it by hand, a process that gives much more insight than a computer algorithm. They also offer to discuss your results further, if anyone wishes to. The best part is that anyone can take part, not just those in the UK.
The e-mail I used to contact the centre is
remyaquarone@btconnect.com Remy Aquarone is the Centre Director. They were able to give me the tests relatively quickly, but it took a few days to grade them.