Coming out not always a good idea for gays - professor.

AAP - Coming out isn't always a good thing, according to a commentator writing in Australia's leading medical journal.

Melbourne GP Dr Ruth McNair, who is also a professor in general practice at the University of Melbourne, says disclosing sexual orientation has traditionally been viewed as a positive step towards a healthy and secure identity.

But it can also have negative consequences, she writes in online edition of the Medical Journal of Australia a day before Sydney's annual Mardi Gras.

"Because disclosure is often met with rejection, hostility or violence, the decision to 'come out' must be very carefully considered and negotiated," she writes.

"I think it's a mistake to make a blanket statement that everyone should come out," she added in a telephone interview.

For some people, at certain times in their life, it could be a mistake.

"It's all about appropriate timing and sensitivity to those around you, as well as your own needs."

Dr McNair told AAP she believed that coming out was generally a good thing in terms of normalising homosexuality and diverse gender identities.

But in some circumstances, it could be problematic and not everyone was equipped to cope with the reaction to coming out.

"If they've built some good support networks and some internal resilience around self esteem then they can cope with negative attitudes," she said.

Dr McNair said celebrities who attracted a lot of attention by coming out publicly could be putting pressure on young people who were coming to terms with their sexual identity.

"It (can set up) that expectation that 'eventually I have to come out'" she said.

But coming out isn't always a good thing and isn't always necessary, she believes, adding that many gay people are able to live their lives without ever feeling compelled to declare their sexuality.

"For some people that's a huge drama but for others it's just perfectly acceptable and doesn't create any psychological problems," she said.

"I think we have to consider that there's a huge range in this spectrum.

"I'm hoping for the day when celebrities and anyone else doesn't even have to come out, it's not even an issue at all, people will just take it or leave it."