this is "nightline." >> tonight americans released in a prisoner swap with iran. former marine now speaking out. >> just really feel proud to be >> and what he did the moment the plane cleared iranian airspace. >> champagne bottles were popped. >> exchange one day before thether hostage homecoming. plus, the story of autism spanning nearly two decades. tonight, the very first diagnosed case of autism. ground breaking therapies nd the surprising wonders found in unimagined places. and tonight the outspoken

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good evening. thanks for joining us. i'm rebecca jarvis. we begin tonight with the americans released in the prisoner swap with iran. an amazing triumph of former marine speaks out telling the world that iran did not break him. this on the 35th anniversary of another iran hostageing us with a strange feeling of deja vu. here's abc's david wright. >> reporter: tonight in germany "washington post" reporter jason rezaian laughed with his wife over a the first joke they've been able to share in more than a year. rezaian, one of five american citizens who were imprisoned in iran, all five of them as part of a broader deal negotiated by the obama administration. >> at long last they can stand tall and breathe freedom. >> reporter: their release in exchange of iranian prisoners

u.s. deal with iran, thawingthat had been frozen since 1979. today 32-year-old amir hekmati was the first of the former prisoners to speak it feel to be back, amir? >> it feels great. i feel lucky. >> reporter: eager to let friends and family know he's okay. >> i didn't wantines down, so i tried my best to, you know, keep my head up and withstand all the pressures that were put upon me. some of which were very inhumane and i'm grateful. semper fi. >> reporter: he's a marine corps veteran, arrested while visiting family in iran. >> my name is amir forced to make this false confession, convicted of espionage and sentenced toon as we got out of iranian airspace, champagne bottles were popped and the swiss are amazing, ter: the scene today a happy echo of 35 years ago this

released the 52 u.s. hostages -- >> look at that inside the door of the dc-9 welcome back to ter: after 144 days of captivity. reporting for "nightline" that morning -- >> during these past orter: that's "nightline" anchor ted coppell introducing the late great peter jennings. >> it has been an unbelievably long day for the 52 american, 12 hours and 9 minutes afterc revolutionary guards finally released them and let them go. >> reporter: kevin just 20 years old then was the youngest of the i remember watching the footage. and you guys were so skinny and bearded and you looked like youll. >> we had. it's just we came out the other end, david. >> watching what's going on in iran right now, are you having some deja vu? >> w clearly the events that are playing out right now halfway

memories of 35 years ago for eporter: he can remember every detail of those days. >> the state government of maine sent over 52 live lobsters for our first meal in freedom.k about that every time you eat lobster. >> i actually do. >> reporter: but for him and his fellow hostages the memories of their time inside areshake. >> if you were caught even whispering, sometimes even looking at your fellow american, you were immediately put into solitarypent 43 days in solitary confinement, david, after trying to escape. >> reporter: that was a year before they were finally freed but their ordeal didn't end in. his family who helped him get through it. >> they're the ones that bring you back to reality, they're the ones who kick you out of the house and say it's time to earn a living. ptsd challenge. it is a very real problem. and i have a number of friends who were there in iran with me who to this day still suffer from that. >> reporter:

is not part of the prisoner exchange. >> please help me. >> reporter: levinson was a former fbi agent whoran nearly a decade ago. his captors sent proof of life three years ago but his wife and son learned the would not be coming home from watching tv. >> not a call from the white house? or the state department? >> no, orter: heartbroken they spoke with my colleague brian ross. >> we're devastated. we had been given assurances over the years that my dad would be a top priority to get hims everybody else, if not more, because he's been held for almost nine years. >> mrs. levinson, do you consider whether bob fact died in captivity? >> no, i will never consider that until i have proof. i believe every day he's trying to come home to our family. we will never give up. >> our thoughts andue to be with the levinson family. the ordeal that they have been

almost nine years now, virtually unthinkable. >> reporter: today the white house vowed the u.s. will continue to press iran for details on levinson's fate. >> we have rea he no longer is in iran. >> reporter: today the u.s. released. seven men convicted of helping iran's nuclear program and dropped charges against 14 none of the iranians freed from u.s. custody elected to go back to iran. the obama administration's with iran remains hugelyrsial. just as the iranian hostage crisis defined jimmy carter's presidency, ultimately dooming his re-election efforts, n deal is at least a factor in the 2016 race. >> the fact is we shouldn't have to trade anything to get our citizens back home. >> we've at how it's happening. >> for one thing the republicans don't buy, iran's assurances that the country has suspended its nuclear weapons the former hostage think? >> do you feel that president obama made a bad deal?

about getting the five men back this week or four men?ing. >> i think the iranians got a better deal than we did. >> reporter: 35 years later, he still hasn't forgiven iran for the 444 days they stole from but he has moved on with his life. he's able even to enjoy the movie "argo" which dealt with one chapter of the hostage crisis all those years says it was tough to watch. >> you don't want to totally relive even in story-telling the most tragic and difficult andts of a very bad period of your life. >> and this moment that we're living today must bring it all back but at least the best moment, which is the moment that you were freed. >> that is so true. you know i think when i am thinking about these guys returning home going to be the person they were before they were captured. hopefully they will be a better

>> reporter: consider this,e prisoners just freed by iran were held longer than the hostages were 35 years ago. they may be on their way back, but it could be years before they feel truly home. i'm david wright for "nightline" in new york. next, a changed medical history in one mother's mission to fight for her son. then later, the endorsementp tonight in iowa sparking big reaction across the nation. here's a little healthy advice. eat well, live well, f what makes you, you. right down to your skin with aveeno aveeno daily moisturizing lotion active naturals oat and 5 vital nutrients for healthier looking skin in just one day. healthy skin equals beautiful skin. tness, add the body wash, too!

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he diagnosis that changed one person's life and the course of medical history.se g agnosed case of autism, a life forever changed and one mother's whose journey helped millions of people and children>> reporter: you would never know it but this man helped make history in the anals of medicine he's known as case number one. his name is donald 1943 he was the first person ever diagnosed with autism, the brain disorder that affects verbal and social interaction. and in many ways, his journey from mirrors the history of autism itself. >> how are you? >> i'm all right. >> reporter: finding donald was the culmination of 15 years of for "nightline" correspondent john donvan and producer caren zucker.

journalists to cover autism on network television, they began in 2001 with jake, this little s then a relatively uncommon therapy called applied behavior analysis, or aba. >> what do you bit of progress? a miracle? no. because this is autism. >> whoa. you're the best. >> and hard work has to take the place of miracles. >> reporter: and they found what some parents refer to as hope in like on this beach in san diego where children with autism were finding some solace in learning how to surf. >> and it's they're starting to paddle the first unwilling child into the swelling sea that you want to ask, is this really a good thing to be doing to these kids? whose idea was this reporter: they explored the private thoughts of a young man

>> do you like her? >> i said i love her. >> oh, you love her. >> butem. >> she don't love me back. >> she doesn't love you back. >> love unrequited, that's what's been weighing on paul. >> i just was rooting for him get what he wants, which is a girlfriend and love and companionship and also seeing just how hard it was for him tothat. >> our book is based here. >> reporter: arm we'd their scripts the duo have turned their first drafts of autism history into a"in a different key, the story of autism." >> your book is really a chronicle of a labor of love. >> "in a different key" if all of these unsung heros who took their love and mobilized, literally, and any

child, case number one, donald triplet's mom mary was a steely advocate for her son, a harsh institution and refusing to let him be marginalized. >> she was keeping up conversation, feeding him language all of the time. really have much language and because of that, ultimately language began to come to him.r late than never. >> she taught him how to drive. >> yeah. >> kind of breathtaking. >> in what way was that an tal love, driving this whole evolution of our understanding of autism? >> it's never giving up. it's never taking no for an was 27 years old, i think, when he first learned how to drive. she was going to do everything she could in her power to give him a at 82 donald today is still an enduring testament to his mother's love,

and donvan's "nightline" stories. >> people ask all the time, looking back was it worth giving up your law practice, m relocating again. and 90% of the words that he has we taught him. so how much is a word is one word worth? every word is priceless. >> reporter: the intimate access the pair received to these remarkable families was no ave a 21-year-old son, mickey, who has autism. and when he was first diagnosed i. didn't know where to and as soon as i hit the ground running with him, i thought i have to just keep figuring out what's out there. and i have to share it with the world. >> like. >> it was a little bit hard to say we want to do stories about autism, stories about what? about autism. it was only 16 years ago but really a lot has 16 years. >> "nightline" was the only show who would do it. we didn't want for people to

we wanted to show out there to help their family. >> reporter: covering autism, organic transition from zucker immersed in the neurological her son. but donvan had a very different journalistic background. tell me about the evolution for you, of, you know, dashingnt, you know, out on every breaking news story, to basically channeling your thoughts and yours one single topic. >> you can't do a story about a person with autism without sitting down and becoming -- forming a n the beginning, i didn't know how. so it was a very big switch from action to very, very personal and i i had to travel more than halfway to them to understand. >> what are the future chapters in the history of autism? >>e not looked at adults. >> as a society we've more or less, when these kids are kids let'

and then they turn 21 and all of that sort of goes down the drain in a lot of cases because people need continuing help but where ar living at home with their parents often and for those 40 years after school, the person with autism has really not gone anywhere, not >> did you have a goal going into the book? >> caren, as a member of the community,out you had a little boy, now you have a man -- i choke up over this. it's been a big -- >> what makes you emotional? >> her kid.hat caren's always said what she wants is when her kid, now a man, is out there in the world, that she won't be the only one whohat it will be everybody -- excuse me -- and she wants this book to get people who read it to be willing to people, to

so i hope we did it. >> reporter: for "nighg in new york. >> our thanks to juju, john, andowerful story. next, donald trump's new endorsement tonight heating up the race and igniting fiery reaction. abc to you by viagra. guys, it's just the two of you. the setting is just right. there's something in the air.hing: about half of men over 40 have some degree of erectile dysfunction. well, viagra helps guys with ederection. ask your doctor if your heart is healthy enough for sex. do not take viagra if you take or adempas for pulmonary hypertension. your blood pressure could drop to an unsafe level. to avoid long-term injury, p for an erection lasting more than stop taking viagra and call your doctor right away if you experience a

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tonight sarah palin announced that she will officially be jumping onboard the let's make a america great

her endorsement getting mixedill this backing give donald trump the boost he needs in iowa? >> i would like to bring up, if i might,palin. >> reporter: tonight donald trump unveiling the newest feather in his campaign's cap. >> thank you so much. so great to be in iowa. >> an endorsement fromaskan governor sarah palin. >> are you ready to make america great again? >> reporter: heating up the republican race with just 13 days to go before the iowa caucus. and palin's not >> you ready for a commander in chief who will let our warriors do their job and go kick ]? >> reporter: they are close for years, both former reality stars. trump on "the apprentice" of course, and palin on "sarah palin's she recently sang his praises on her talk show "on point with sarah palin." polls.

room today glorious but not everyone is so pumped. the new york that will hit stands tomorrow. endorsement likely disappointment for presidentialfulful ht wing and bitter clinging and proud clingers of our guns, our god, our religions reporter: right now it's difficult to predict how they will influence the race. >> good evening, my fellow americans. increasingly likely that tina fey and amy poehler will reprize those famous roles on st. night nd i was told i would be addressing you alone. >> of course we will continue to follow this developing story tomorrow morning on "gma." thanks so much for ys, we are online on our "nightline" facebook page and at abcnews.com.