Bagpuss - I'd go for selective truths. You don't have to outright lie - but its quite likely that some interviewers are likely to be unsympathetic and ill-informed on the subject (they may be uncomfortable with the subject & you certainly don't want them to feel uncomfortable during the interview). So its wise to suss them out a bit before volunteering too much information.
Total & complete honesty is not essential - they will be expecting you to present yourself to your best advantage - and they will be doing the same....
Best of luck.
Kris