When Fran Houston felt like she was ready to take her life a few years ago, her friend, Martin Baker, wouldn’t let her do it. He spent long hours on the phone with her, mostly just talking, serving as a sounding board and being a consistent, dependable friend. Twice a day for more than eight years, Houston and Baker have maintained a routine of checking in, taking stock and looking forward to the next day through a ritual of phone calls from one continent to another.

Houston, 59, lives in Portland and Baker, 58, lives in northern England, some 3,000 miles away. They have met in person just once, when Houston traveled to England on a vacation in 2013. But they Skype at least once a day, and often twice. “I wouldn’t be here if Marty wasn’t my friend, if he wasn’t my best friend,” Houston said. “I would have taken my life a long time ago, but Marty has made it really difficult to leave.”

Along the way, they’ve written two books together about their experiences, in hopes of helping others who are living with depression and considering suicide. It began when Houston suggested, “You should write a book about what it’s like to be friends with someone who is bipolar.”

Baker was initially daunted, but thought it was a brilliant idea. “If she had come up with an idea for a photography book, I would have said, ‘Maybe.’ But the idea was so sound,” Baker said by Skype from his home in Newcastle Upon Tyne. “There are a lot of books for parents and for partners, but there was nothing out there focused on supportive, caring friends.”

They take a nonclinical, nonacademic approach and offer tips and ideas about how to help friends who live with bipolar disorder, depression or other mental illness. Houston has lived with bipolar disorder, chronic fatigue syndrome and fibromyalgia for more than 20 years, and struggles with depression and bouts of mania. She had worked as an electrical engineer, but left her job after a series of personal setbacks led to an onset of mental illness.

Their first book, “High Tide, Low Tide: The Caring Friend’s Guide to Bipolar Disorder” from 2016, is a how-to guide for supporting a friend living with mental illness and includes their back-and-forth exchanges with a concentration around the time when Houston was living with severe mental health issues, including persistent suicidal thinking. Their latest, “No One Is Too Far Away: Notes from a Transatlantic Friendship,” came out last year and began showing up in local bookstores this summer. It is a collection of their most popular posts and articles from their ongoing blog, Gum on My Shoe, where they offer mental health support and insight from the ground up. They write their posts separately, and Houston sends her writing to Baker so he can edit it. They didn’t write the books to make money. They’ve sold about 1,000 copies of the first book and fewer of the second so far. They find value in their work by sharing it with people who need it the most.

Neither entered the conversation as an expert on the subject, though Baker has become one. Through his friendship with Houston, Baker has taken an applied suicide intervention skills training course and become a trained mental health first aid provider, expanding his efforts to help his friend in Maine by getting involved in the well-being and mental health team at his workplace in England and writing about mental health issues for the company blog. HealthCentral, a website dedicated to healthy living, recently featured Baker for helping to change the public perception of bipolar disorder. He works in IT.

Sarah Fader, who writes about mental health issues for the Huffington Post and is chief executive officer and founder of the nonprofit organization Stigma Fighters, published “No One Is Too Far Away” through her company Eliezer Tristan Publishing, which focuses on fiction and nonfiction writing about survival.

“Their story hit home for me, as someone who suffers from bipolar disorder,” Fader said in a phone interview. “There are a lot of myths and stigma surrounding bipolar in general. Their book fights against that stigma and gives clarity not only on the illness, but how important it is to have a friend in the time of stress, regardless of a diagnosis. Bipolar depression is so severe, it’s nice when you have someone to talk to, because what you need is someone to listen.”

She committed to the project because “I have never seen a friendship like this and never seen a compilation of notes quite like this. I love their dynamic and I find their friendship very touching. Marty is a very good person and a very good friend. I also wanted to give Fran a platform to be able to express what she was going through and how Marty has helped her.”

“No One Is Too Far Away” is Houston’s third book. She published her first, a collection of photographs and stories of longtime residents of Peaks Island called “For the Love of Peaks,” in 2010. It was during her work on that book that she became friends with Baker, under difficult circumstances.

Houston reacted negatively to a comment Baker posted on a mutual friend’s Facebook page. That friend was struggling through a dark period of depression, and Baker chimed in, “Flooding light and love into your world.” Houston told him that she understood his sentiment, but told him that wishing someone well who is considering taking her life wasn’t helpful.

“He gave bad advice,” Houston said. “But we became friends out of that exchange.”

Their friendship has been constant and consistent. It started with phone calls, then turned into video chats. They usually talk during the afternoon and again at night, when Baker’s schedule at home in England, where it’s as much as five hours later, depending on the time of year, allows pockets of time to focus on his friend in Maine. Sometimes it’s a quick, casual conversation, other times they will watch movies together, with Houston turning her laptop so Baker can watch her TV monitor in real time. “I just get twizzled around to face the screen,” Baker said.

At other times, Baker has helped Houston out of jams. When traveling, she will share her travel information so he can track her progress and help her navigate potentially stress-inducing situations.

Baker said he has never considered walking away from the friendship or the ritual of the phone calls, even when he is on vacation with his wife and family. “There’s a line that I must have said to Fran years ago, and it comes up now and again: No matter how tough things get, I never don’t want to be on this call. I never don’t want to turn up,” Baker said. “It gets scary at times, but I am not afraid. I am here. I am not going to run away. We hold each other accountable in a lot of ways.”

They are not always great company. They bicker and fight, and Houston said there are times when she is not in the mood to be friendly. “I don’t want to talk to Marty, I don’t want to talk to anybody. But then I say, ‘All right, it’s 2 o’clock. I have to get on with Marty.’ But by the end of the call, I am happy.”

Collectively, their books offer a window into the challenges of the daily life of someone living with bipolar disorder. In “High Tide, Low Tide,” they include a passage that Houston wrote and shared with friends during a particularly acute period of depression several years ago. Her post foreshadowed the challenges of being her friend.

She wrote, “the crash has come .. will you .. be .. in it .. with me .. it will be .. fiercer than … the mania .. deeper than any dark ness .. i have known .. before .. guaranteed.. and i .. will be able  .. to give .. you .. nothing.. in return .. no thing .. but dark ness .. emptiness .. void .. of heart .. care for me .. or not .. your choice .. ever your choice . free dom .. reigns .. reins .. rains .. for ever more .. end less ly .. this is not .. a light matter .. it is dark .. and deep..”

In “No One Is Too Far Away,” she writes about her decision to share her feelings. “The reason I write about invisible illness is because this is the biggest part of my world. The reason I share it on my social media, rather than only in my blog or in a closed group, is because my biggest desire and fervent passion is for us all to talk about it out loud, upfront, in the mainstream. That is where it is spoken about least due to stigma and shame. Too many people have died from lack of talk, lack of connection, and lack of understanding. We who are ill have had to hide behind closed doors for way too long. Since I’ve lost everything short of my life, I am no longer afraid. There is nothing left to lose but life itself. I am indeed a lucky one to still be alive.”

Houston lost many friends in Portland because of her illness, especially when she was promoting “For the Love of Peaks” and showing her photography in local galleries. She lost control of personal boundaries, said inappropriate things. “I was in a state of mania. People might have called it creativity, but it was mania,” she said. “The more accolades I got, the more manic I got. I was getting attention and I didn’t know how to process it.”

Out of caution and fear of going back into those dark periods, Houston has largely avoided doing any public speaking related to “High Tide, Low Tide” or “No One Is Too Far Away,” leaving most of that to Baker over in England. She prefers being in the background and letting her story speak for itself. “I’m there if people need me, but I’m not the famous person. That’s Marty. He’s made up differently than me. That’s his job,” she laughs.

Donna Betts became friends with Houston through her work with the nonprofit agency Family Hope, which Betts founded after her oldest son, Josh, died by suicide 10 years ago when he was 23. She has since stepped away from that work, but has remained friends with Houston.

She admires the friendship that Houston and Baker have built, and wishes her son had someone like Baker in his life when he was in crisis. “From my perspective, being able to talk to someone is so important. We feel so isolated and assume we are the only one going through something,” Betts said. “Their friendship is actually quite amazing. To have that perspective from people who have been there, who are there, who are going through it and being successful in their journey is really invaluable.”

Donna Murphy, another longtime friend, met Houston through their work in a group called It Takes A Community, which brought together people who had been touched by mental illness in different ways to build awareness and break down stigma. At the time, Murphy was working for what was then Maine Mental Health Partners, now Maine Behavioral Healthcare. “This was before Marty had come into her life, and I saw that Fran was struggling. She was really in the throes of the more manic behaviors as a result of her bipolar disorder. I was just trying to engage her and get to know her better,” she said.

The friendship of Houston and Baker proves the importance of reaching out, listening and not being afraid, Murphy said.

“You don’t need to be an expert to do that,” she said. “I think they are both extraordinary people. I commend Marty for what he has been able to give and do for Fran, and at the same time I think Fran is brave and courageous for openly sharing what she has experienced with her mental illness so that others can learn from her experience.”

Baker said he gets as much from the friendship as he gives. “What I get out of this is a best friend and a mutually supportive and mutually beneficial friendship. We are friends. We are buddies. That’s why we are still together,” he said.

The key message in both books is that distance does not matter. “We like to say that no one is too far away to be cared for or to care,” Baker said. “That can be 3,000 miles or the next street over. The physical distance is important in certain respects. There are things we can’t do. But there are things we can do. The distances are as relevant as we choose to make them.”

As for saving Houston’s life, Baker will take her word for it. But he won’t take credit.

“I didn’t save her. I can’t do that,” he said. “I can only be here to help her save herself.”