RICHMOND — Gov. Ralph Northam on Monday signed a bill banning conversion therapy for minors, the first LGBT rights measure to reach the Democrat's desk this year.

Virginia will become the 20th state — and the first in the South — to outlaw the therapy, a widely discredited practice that purports to change a person’s sexual orientation or gender identity. Critics say it is traumatic for patients and has led to suicides.

The ban, which takes effect July 1, will not apply to adults who choose the therapy for themselves.

“This issue is personal for me, as a pediatric neurologist who has cared for thousands of children,” Northam said in a statement. “Conversion therapy is not only based in discriminatory junk-science, it is dangerous and causes lasting harm to our youth. No one should be made to feel wrong for who they are — especially not a child. I’m proud to sign this ban into law.”

Many other landmark LGBT rights bills have also passed the House and Senate and are on their way to the governor this year, during the first session in a generation with Democrats in control of both legislative chambers.

Among the other bills is one that would make Virginia the first Southern state to ban anti-LGBT discrimination in employment, housing and public accommodations.

With Republicans in control of at least one chamber for the past quarter-century, such legislation has been blocked in past years.

A few Senate Republicans were willing to team up with the Democratic minority on measures such as banning discrimination against LGBT people in housing and public employment. But those bills never got to the floor of the House of Delegates, where Republicans were also in charge.

The landscape changed suddenly after Democrats flipped both chambers in November elections.

Conversion therapy for minors is already banned in the District and 19 states, including Maryland, according to the Movement Advancement Project, which tracks LGBT legislation.

North Carolina prohibits only the use of taxpayer dollars for the therapy.

Under the bill proposed by Del. Patrick A. Hope (D-Arlington), therapists cannot attempt conversion therapy with anyone under the age of 18. Violation of the ban would be grounds for disciplinary action by state health regulators.

Adam Trimmer, who lives in the Richmond area, came out as gay as a teenager and underwent conversion therapy. Now he is Virginia ambassador for Born Perfect, a national campaign to end the practice.

Trimmer, 30, said the sessions convinced him for some time that his homosexuality was the result of an “overbearing” mother and emotionally distant father, something that he said “wrecked our relationship.”

“Throughout all of it, I was still gay,” he said. “I felt like I did something wrong. And it was years afterward that I still experienced shame. . . . Our community deserves pride and the absence of shame.”

Hope’s bill passed the House 66 to 27, with every Democrat and 11 Republicans in favor. Another seven Republicans did not vote. The Senate passed it 22 to 18, with all Democrats and Sen. Jill Holtzman Vogel (R-Fauquier) in support.

The General Assembly has also passed an identical Senate bill, proposed by Sen. Scott A. Surovell (D-Fairfax). Northam is also expected to sign that measure but was under time pressure to sign Hope’s bill because it had passed earlier in the session.

The governor is likely to do a ceremonial signing of all LGBT rights bills sometime after the General Assembly gavels out of its 60-day session on Saturday.