A “mass shooting” (four or more shot in one incident) has occurred in the United States every day this year, but not in Maine.

Should we knock on wood or pat ourselves on the back?

Clearly the causes of gun violence are many and disputed. But the conditions contributing to mass shootings are much clearer.

Four factors characterize most such tragedies:

• mental/emotional disturbance or illness

• suicidal intent

• easy access to guns

• drugs.

How does Maine rate with regard to these factors?

• Maine’s mental health program is a mess.

The principal mental health facility (Riverview) has failed to meet even minimal federal standards since 2012, with the result that all federal aid ($20 million per year) has been cut and state funding has not replaced it.

Institutional treatment of the ill has been replaced by emergency room treatment and immediate return to the community, for better or worse.

A bill that would allow family members to request that law enforcement agencies temporarily restrict gun ownership by emotionally disturbed individuals died in legislative committee last spring.

Until recently, the Legislature prohibited reporting into the FBI database used for federal background checks the names of mentally ill persons found to be a danger to themselves or others, as required by federal law.

The result is that mental patients in many cases have not received the treatment they need, and have not been designated as prohibited gun buyers.

They can pass the federal background check not only in Maine but anywhere, and legally purchase any gun or as many guns as they wish.

• Most mass shooters expect to be killed by police or choose to kill themselves, and such is the usual outcome.

Maine, like many rural states, has a high suicide rate – only 13 states have a higher rate.

• The often-repeated view that Maine has a high rate of gun ownership is wrong.

Per capita gun ownership in Maine is about average, but who can buy guns in Maine is far from average.

Twenty-seven states have universal background check laws that restrict more tightly than does federal law who can buy guns.

A universal background check law in Maine was vetoed by Gov. Lepage in 2013 so that, at present, buyers who cannot pass a federal background check, or a New Hampshire or Massachusetts or Connecticut or New York background check, easily can buy any gun they like at many gun shows in Maine, some at supermarket parking lots, from any private seller, or through Uncle Henry’s.

No questions asked, cash and carry (and carry concealed if you like).

• Drug abuse in Maine is an enormous problem and it is getting worse.

And with the drugs comes gun violence.

Drugs are big business and drug dealers don’t settle their business disputes in small claims court.

Maine’s Commissioner of Public Safety recently wrote in this paper that Maine’s drug enforcement program “is severely underfunded.”

Even more so is its drug treatment program.

Portland police regularly “catch and release” the same offenders over and over because treatment programs are not available.

While heroin addiction has increased over 300 percent since 2010, the number of Maine facilities treating such addiction has declined by 25 percent.

Better gun laws will not prevent all gun violence, but the data is clear that they will reduce gun violence.

Mainers understand this and by eight or nine to one support adopting more comprehensive background checks that will close the gun show loophole and help keep guns in responsible hands.

By far, most gun owners also support such a law.

Maine has been lucky and it is time to stop trusting to luck.

Hopefully we can do so in part by adopting a universal background check referendum in November 2016.

Meanwhile, knock on wood.