We had someone* who had a gap in their CV because they’d had a prison sentence for a crime they’d not declared on the application form 
I think I’m supposed to ask the question as part of the recruitment process but for me it’s a formality. If someone’s had a break due to childcare, mental health, or they just fancied a break, it makes absolutely no difference to our decision-making process. I’m much more interested in what they have done / are able to do.
*a different department, I should add