Since 2012, the office had been regularly airing public service announcements meant to promote gun safety and reduce the stigma around seeking help. But the report found that as of August, none had been broadcast for more than a year.

Dr. Thompson, now with the Cohen Veterans Network, a nonprofit group, said she was dismayed at the falloff.

“This is such an important issue, we need to be throwing everything we can at it,” she said. “It’s so ludicrous that money would be sitting on the table. Outreach is one of the first ways to engage with veterans and families about ways to get help. If we don’t have that, what do we have?”

As the office’s outreach efforts dwindled, nationwide monitoring showed a steady increase in the suicide rate among veterans age 18 to 34, which is now about 45 deaths a year for every 100,000 people, more than three times the overall national average.

The suicide prevention paralysis is one of a number of recent stumbles at an agency that has seen significant turnover of experienced staff and top leadership in the last 18 months. Mistakes in managing the G.I. Bill program led to late or incorrect housing allowance payments for more than 80,000 veterans enrolled in college. A sweeping $16 billion overhaul of the V.A.’s electronic health care records system has hit a number of obstacles, and the expert who was brought in over the summer to lead the project quit within a month.

Curt Cashour, the department’s spokesman, said the responsibility for the problems in the suicide prevention program lay with Dr. David J. Shulkin, Mr. Trump’s first secretary of veterans affairs, who was fired in March. He said Dr. Shulkin’s successor, Robert L. Wilkie, had taken steps to address the issue.

“Within weeks of his arrival at V.A., then-Acting Secretary Wilkie appointed Dr. Keita Franklin as V.A.’s new suicide prevention director, and she is reviewing the spending for this important program,” Mr. Cashour said in a statement.