In addition to Mr. Christie, the members of the commission are Gov. Charlie Baker of Massachusetts (a Republican), Gov. Roy Cooper of North Carolina (a Democrat), Patrick Kennedy, a former congressman from Rhode Island (a Democrat), and Bertha K. Madras, a Harvard Medical School professor who specializes in addiction biology.

Dr. Tom Frieden, the director of the Centers for Disease Control and Prevention during the Obama administration, said declaring a public health emergency under the Stafford Act, as the commission recommended, was usually reserved for natural disasters like hurricanes.

“This is not a natural disaster; it’s one caused by overprescription of opiates and flooding of illegal opiates into the country,” Dr. Frieden said. “The critical measures for reversing the opioid epidemic are improving prescribing and increasing interdiction of illicit opioids.”

Gary Mendell, the founder and chief executive of Shatterproof, an anti-addiction advocacy group, said an emergency declaration would be “a significant first step towards acknowledging the severity of the crisis we face and the urgent need for action, including national emergency funding and suspending regulatory hurdles that limit our ability to save lives.”

Mr. Cooper said in a statement that he considered the report “incomplete when it comes to making sure all Americans have access to affordable health care, which includes mental health and substance abuse treatment.” He added, “I urge the commission to make a stronger stand on the accessibility and affordability of health care.”