No, unfortunately, our house is drafty and damp as it is. We run a dehumidifier just to try to prevent as much mould as we can already. My mum used to use a humidifier with me when I was little and it did help, but my rationale is mould is worse for respiratory problems than some dry air, so I'd rather not. It depends what sort of climate you live in though and how well ventilated your house is. Our house is poorly ventilated, which we can't fix as we rent, and our climate is already wet and damp enough.