New York (CBS)  -- TROOPS AND MENTAL HEALTH AFTER IRAQ AND AFGHANISTAN

For troops who've seen duty in Iraq and Afghanistan, is there really a serious problem with what's now called post-traumatic stress disorder? The Rand Corporation has now done a study.

"Our study finds serious prevalence of post-traumatic stress disorder and depression of the one-point-five-six million troops who have served -- about 18-and-a-half percent," said Terri Tanielian of the Rand Corporation.

Almost one in five.

The Army admits there's a serious problem with many returned troops, says CBS News Correspondent Kimberly Dozier.

"Usually doesn't show up in the first month back.  It takes a few months -- but the nightmares, the flashbacks set in -- and then these guys and gals are afraid to ask for help," said Dozier.

They're not the only ones who pay a price.  We all do, says the Rand study.

"The cost associated with these conditions over two years to American society totals as much as six billion dollars," said Tanielian.

Terri Tanilian is co-leader of the Rand study.

"Half of these veterans with this need for care are not seeking help or getting minimally adequate services," said Tanielian.

Why don't they seek help?

"The problem is the stigma. There are many old-fashioned military commanders -- not just in the Army, but in the Marines, as well -- who believe that post-traumatic stress disorder doesn't exist.  When they see someone drinking or using drugs or going AWOL, they say that person is just trying to use the PTSD diagnosis to get away with it," said Dozier.

It's important they get help says Col Loree Sutton, who heads new Pentagon center on brain injury.

"If you have a problem and you need help, and you don't get it, chances are something will go awry with your career -- because bad news and difficulties and conflicts don't necessarily get better on their own," said Sutton.

To address this makes sense, says the Rand study, even in terms of dollars and cents.

"Eliminating the gaps in access to and the quality of treatment could reduce the long-term societal cost to America by one-point-seven billion dollars," said Tanielian.

CATHOLIC CHURCH TACKLES PRIEST SHORTAGE

"In the name of the Father and the Son and the Holy Spirit and the Holy Spirit, peace be with you," said Pope Benedict XVI.

On his visit to the United States, Pope Benedict XVI comes at a time when the Church is under great stress in this country.  One reason is a shortage of priests. Benedict has said that what is most important is good priests, not many priests.

Yet the number of men in the priesthood here has dwindled from 58,000 in 1970 to 41,000 now.  And the Church is now welcoming not only young men, but those in mid-career.

Father Paul Arnoult was ordained a priest at the age of 42, after 12 years in the pharmaceutical industry.

"I had a great job, wonderful company, fantastic people, best boss I've ever had -- but something was just kind of missing as I went along," said Arnoult.

The word "vocation" comes from the Latin for a calling.

"The call came when the call came, you know.  I wouldn't have been listening, I wouldn't have been ready -- no way -- at 25," said Arnoult.

The average age of new priests was 28 in the 60's.  Now, it's 37.  A former teacher, Father Edward Benioff is 37.

"We have a little more wear and tear on us -- and we can relate with, again, the ups and downs of life to people," said Benioff.

Father Tom Daly is the vocation director of the Archdiocese of San Francisco.

"One of my former teachers said:  'Being vocation director at this time -- isn't that like being an Army recruiter during the height of Vietnam?'" said Daly.

It is like that. Young men have so many options now.  It's a little later in life when you've been around the block a few times that you see things differently, says Patrice Touhy.

"You realize that your life is half over, and what really have you done with it," said Touhy.

She is with a website VocationMatch.com, directed at those seeking a second, more fulfilling career.
 
"I love being a priest.  I've been a priest nine months, and I love it!" said Arnoult.

What for the church is a crisis, for men like Father Arnault is an opportunity.

"God opened doors, and it worked out," said Arnoult.

FULL MOON FEVER

When the moon is full, as it will be this Sunday night, it is full no matter where on the earth you are, and the same side of the moon faces you. 

The same silver moon, shining down through the trees.  Nothing special about that, astronomers say.  It happens every 29-and-a-half days.

"The full moon really isn't unusual in any respect, except that it's full," said Deane Peterson, an astronomer at Stony Brook University's Earth and Space Sciences Center in New York.

Yet for thousand of years we humans have seen it as special.

"...Cultures around the world that celebrate the full moon -- there are Buddhist holidays, lunar calendars, festivals all based on the full moon," said Eric Chudler, a neuroscientist at the University of Washington in Seattle.

Chudler has studied the full moon's influence on human behavior.

"So, it's not just here in the States, but all over the world and many, many different cultures -- the full moon plays a very significant part in life of the people," said Chudler.

It's from the lunar effect we get the words "looney" and "lunatic."

"A large percentage of the population believes that the full moon causes some kind of abnormal behavior," said Chudler.

For our television broadcast this "Sunday Morning," Thalia Assuras spoke with Chudler.

Assuras: Does it cause more suicides?
Chudler: No.
Assuras: More mental illness?
Chudler: No.
Assuras: More aggression, criminal behavior?
Chudler: No.
Assuras: More accidents?
Chudler: No.
Assuras: Abnormal behavior?
Chudler: So far, the data says no.
Assuras: Hmm.  So, how do you really -- what does this tell you?
Chudler: Well, it tells us that people like to have order in their lives, and that by assigning blame to something that -- to events that they can't control -- it helps them control the situation and helps reduce stress.

HAPPINESS GETS BETTER WITH AGE

Each year between 1972 and 2004, interviews were conducted at the University of Chicago's National Opinion Research Center with 1,500 to 3,000 men and women of different ages, to find out who was happier than whom. 

And it turns out that while 15 to 33% of 18-year-old Americans considered themselves happy, the older people got the more likely they were to say they were happy.  More than half of those in their 80's reported that they were very happy.

The happiness survey did find that it's better to be healthy than sick, better to be rich than poor -- to live in good times, rather than bad.  No surprise there.  

But when it comes to age, when the question was put this way: "Taken all together, how would you say things are these days? Would you say that you are very happy, pretty happy or not too happy?"

It seems that with the exception of the baby boomers, who were the least happy because many didn't get as much as they thought was coming to them out of life the older people got, the more likely they consider themselves happy.

Sociologist Yang Yang says it proves the hypothesis that improvement in self-esteem and other traits that contribute to happiness tend to come with age.  That's why with a smile and a twinkle in the eye.