has gained the reputation of being the hippie capitol of the world.

In the 1960s, a counter-culture sprang up based on peace, love, and psychedelic drugs like LSD.

The kids who take LSD aren’t going to fight your wars. They’re not going to join your corporations.

Timothy Leary had an insight that if you changed yourself

it would change the world and change the society.

Authorities quickly cracked down on the drug, fearing its alleged health effects.

Instant insanity

Chromosome damage

It may affect your unborn children.

The frightening thing about LSD, of course, is that it lurks in the bloodstream like a tiger.

But today, half a century later, some psychedelic drugs are making a comeback

-- not on the streets, but in the laboratory, which is where it all began.

There’s really no other example that I can think of in science

where an entire area of research was put on the deep freeze for decades.

In January of 1967, thousands of young people gathered

in San Francisco’s Golden Gate Park to mark the dawn of a new era.

There was political speakers. There was countercultural speakers.

There was rock music and yes, the LSD flowed like wine.

A psychologist who had taught at Harvard, named Timothy Leary, praised the power of LSD,

an increasingly popular mind-altering drug.

Turn on, tune in, drop out.

For Leary, turning on with LSD was the key to achieving a higher level of consciousness.

When people say "What’s the use of LSD?" I translate that into "What’s the use of my head?"

That’s a fascinating problem. Suppose man can use more of his brain.

People that took the drug felt if everybody can have this experience, the world

would be a profoundly different place, a much better place and within months

this drug, this sensibility, this countercultural revolution, if you want to call it that,

attracted mass media from around the planet. And that blew it up.

The city of San Francisco has been warned of a hippie invasion come summer

in numbers almost too staggering to comprehend.

I think a lot of people intuited in the establishment that LSD was a direct threat to industriousness.

I mean, what, you want to drop out, not get a job? You know just go and live on the street in San Francisco?

I think this was seen as profoundly threatening to the social order.

Psychedelics are not groovy, ok? Psychedelics are dangerous.

Former New York City Police Commissioner Howard Safir

was an undercover narcotics agent in the late 1960s.

Back then everybody thought of LSD was for hippies until suddenly kids

who looked like they were straight showed up in emergency rooms.

There is a steady flow into San Francisco hospitals of young people who have freaked out

and been picked up by the police in a state of desperate terror.

I had seen people on the street who had no idea where they were.

I had arrested people on LSD who were incredibly violent.

So it wasn't the peaceful, non-harmful, easy drug that Timothy Leary professed it to be.

There is nothing smart, there’s nothing grown-up or sophisticated in taking an LSD trip at all.

They’re just being complete fools.

Headlines warned of additional dangers including genetic damage,

involuntary hallucinations, and even suicide.

20-year-old Diane Linkletter killed herself on October 4th.

After Diane Linkletter fell from a sixth-story window in 1969,

her father, TV personality Art Linkletter, blamed LSD.

Anybody who has said anything which would encourage my daughter to take LSD

was unwittingly a part of being her murderer.

I think that raised public consciousness probably as much as anything that happened in the '60s.

President Nixon went to the Narcotics Bureau today to sign a drug bill.

In 1970, the Controlled Substances Act made LSD a Schedule I drug,

the class of dangerous substances with high potential for abuse and no accepted medical use.

But before it became a street drug,

LSD had been developed in the labs of a Swiss pharmaceutical company.

They weren't sure what it could be used for and they sort of fanned it out to the scientific community.

It was all legal in those days. Nothing controversial about it at all.

Bill Richards helped conduct scientific research with LSD and other psychedelics

as a young researcher in the 1960s. He says the early experiments in the 1950s were rudimentary.

You'd simply be given the drug and see what happens.

Do you find any difference between one half of your body as opposed to the other half?

Well, I have sort of a wavering tendency. I don’t know which half is trying

to get into the other half, but somehow or other I seem to be going like that.

Most people got mildly psychotic and the thought then

was that it might help us understand schizophrenia or other severe forms of mental illness.

The CIA investigated LSD as a potential truth serum,

and the Army tested the effect LSD might have on soldiers in battle.

Some early test subjects had bad reactions, and some scientists began to use LSD

in a more controlled manner, as one step in an ongoing program of psychotherapy.

There was a lot of excitement about the potential of psychedelics in treating alcoholism.

And then we moved into working with terminal cancer patients, treating anxiety and depression.

You’ve taken head-on the biggest thing that’s bothered you.

The LSD experience was closely monitored and guided,

with music and eyeshades used to calm and reassure the patient.

At the end I felt a great weight had been taken off me

like it was something had opened up and things could be seen in a different light.

There was an incredible spirit of excitement.

International conferences, papers published on LSD and psychotherapy.

But as the 1960s progressed, and as people like Timothy Leary spread LSD

from the laboratory to the counter-culture, the drug’s potential for therapy was overshadowed

by stories of its dangerous street use.

I'm a pretty black and white guy.  There was never any thought in my mind

that there were positive uses for LSD.  I saw the results and the results were not pretty.

And after LSD was declared a Schedule I drug in 1970,

funding and support for psychedelic research dried up.

This is the most powerful tool ever discovered to look at consciousness.

And it was taken away.

Today, the psychedelic glow of the 1960s has faded, and recreational use of LSD,

which is still illegal, has fallen to low, but steady, levels.

But in the world of science, a new age is dawning.

Folks are studying a lot of things with psychedelics now.

Matt Johnson is a professor of psychiatry at Johns Hopkins University.

He says that instead of LSD, most research today is done with psilocybin:

a similar psychedelic, with one important difference.

It comes down to the spelling of psilocybin.

It’s a hard word to spell but at least it’s not spelled LSD, which is a very strong word that people react to.

In recent years, more than a dozen studies at several universities have investigated

the use of psilocybin and therapy to treat problems ranging from addiction

to depression and anxiety in cancer patients.

In 2010, Sherry Marcy was diagnosed with stage-three endometrial cancer. Her life changed overnight.

I had been an athlete all my life, so to suddenly have cancer was shocking.

I think I looked up from the phone call and said to Nancy, "I’m stunned."

After Sherry’s diagnosis, even prior to treatment,

it was just like this doom had descended on her and then subsequently on us.

Undergoing both radiation and chemotherapy,

Sherry began taking anxiety, sleep, and pain medications to cope with her symptoms.

It took away my whole identity.

I wasn’t who I used to be and I wasn’t the person that Nancy had formed a life with.

I’m about to cry now just getting back into it. It felt like I sat on the couch and did nothing all day.

Then in 2012, Sherry read an article that mentioned a Johns Hopkins study on psilocybin

and cancer patients who were suffering from depression and anxiety.

It sounded like it fit me. It just fit.

Eight weeks later, the couple traveled to Baltimore,

where Sherry had the first of two psilocybin doses.

There was sort of a ceremony about taking the pill. And then I was there for six hours reacting to the pill.

And I process by talking, so something I really learned about myself then,

because every now and then they would say,

"Now, why don’t you stop talking and just feel?"

But what happened to me was that I ended up getting totally reconnected, first to Nancy.

Nancy and I had a wonderful life together, and it could go on, and I hadn’t known that before.

And then also my kids, getting reconnected to them.

So there was this family dynamic that just reformed and that was - that was just great.

She was just lighter. Immediately a difference. And then we came home, and it persisted.

Today Sherry, who is now cancer-free, says the psilocybin study helped her re-engage with life.

It wasn’t like it was psychedelic for me. It was just me, back.

I don’t know how it did that exactly, except to broaden out, you know.

It's like you lift up your head and you take a good long look and you start seeing things again.

Recent brain imaging studies have investigated the impact of psychedelics.

They’ve found that both LSD and psilocybin foster connections

between parts of the brain that normally work independently.

It’s an exciting area in neuroscience right now. More and more groups are jumping in and it’s only just begun,

but people should really be aware that there are potential dangers.

Those dangers can range from a temporary bad reaction, to the triggering or worsening

of an underlying psychiatric condition, so caution is a guiding principle in today’s research.

But it turns out that not all of the claims made about LSD in the 1960s were true.

Studies have found little evidence that it damages chromosomes or causes birth defects.

And Diane Linkletter’s autopsy found no drugs in her system when she died.

On the other hand, Sherry Marcy says Timothy Leary didn’t get it right either.

I think the emphasis was wrong. I mean, the turn on doesn’t have to be emphasized at all.

The drop out is an absolute mistake. But the tune in is crucial. I tuned in.

Tuned in to the world, to me, to things I used to love, to my relationships to my family.

Tune in is what it’s all about.