CAPE ELIZABETH – Isabel Johnston, a senior at Cape Elizabeth High School, has gone from a freshman who once struggled academically due to medical issues, to a soon-to-be-graduate who loves to learn, especially when it comes to math.

“At Cape I have loved all my math teachers, and it’s been my favorite subject,” Johnston said. “I think I may even major in it in college. I love math, and I love problem solving.”

Johnston is one of about 125 members of the class of 2014, which is holding graduation exercises Sunday. Scarborough and South Portland are also holding high school graduation ceremonies the same day.

Johnston, an honors student, has served as vice president of the student council for all four years of high school, is a member of the high school math team, which won the Class B state championship this year, and served on a committee that helped to bring the first TEDx Youth Event to Cape Elizabeth. She said the TEDx Youth Event featured “influential people in the community that are passionate about what they do or who had stories to share.” According to the TEDx website, the nonprofit is devoted to spreading ideas, usually in the form of short, powerful talks of 18 minutes or less on a range of creative topics, including technology, entertainment and design.

Beyond scholastic pursuits, Johnston also played lacrosse and ran indoor track her freshman and sophomore year.

Cape Elizabeth High School Principal Jeffrey Shedd said Johnston entered high school with “very serious attention concerns and struggled to focus on her school work.”

Now, a graduating senior, “she has really grown and matured,” Shedd said. “She has emerged as a wonderful student and is a highly accomplished leader.”

Johnston didn’t always consider herself a leader, though.

In the fifth grade, she was diagnosed with attention deficit hyperactivity disorder (ADHD).

“I was battling with it for a long time, and freshman year I went on medication to help me cope with it,” Johnston said.

Her medication, however, produced side effects, she said, making her feel depressed, and because of it her grades began to suffer. Johnston couldn’t focus in class and had trouble staying organized, she said. She mainly wrestled with taking timed tests.

At the beginning of her junior year, Johnston tried a new prescription, she said, which proved to be more effective. In addition, she also received support by having a plan that gave her extra time to complete assignments.

“That was a very long process, meeting with my teachers and advocating for myself for the extra time I needed,” Johnston said. “It was really frustrating never to be able to finish a test.”

“I wasn’t always as happy and positive and talkative as I usually am,” Johnston added. “I was trying to find a balance between that and my work ethic, because I obviously wanted to do well in school. I just wanted to be myself.”

Despite her medical setback, Johnston’s ambition to be involved at her school and in her community has never wavered. She even considers herself an “A” student this year, having received high honors her first semester.

For all four years of high school, Johnston said that she managed to accrue a 91 out of 100 grade point average, which translates to a B-plus average.

While helping to lead the student council has been a lot of work, said Johnston, “It’s really rewarding. It’s a lot of fundraising and we put on events like winter fest and spirit week. We have assemblies, organize games, and offer fun things for the students to do.”

As student council vice president, Johnston has also helped organize the prom and is now organizing the graduation and senior banquet, she said. In addition, for three years, Johnston has been a member of Natural Helpers, a peer-elected group that helps students deal with school-wide concerns such as depression or other disorders.

“We go to seminars to learn skills (to address) suicide and eating disorders so we can be knowledgeable if we ever encounter them,” Johnston said.

When senior year came around, Johnston said that she was able to focus more, primarily because seniors have more flexibility in choosing which classes they take. Johnston dropped French, which she struggled with, and took physics and pre-calculus, which she loves.

“It was so much better to have classes that I really care about,” Johnston said. “It made me want to learn a lot more.”

After graduation on June 8, Johnston plans to attend the College of Charleston in South Carolina in the fall, though she is not positive if she will major in math.

Johnston is excited about being able to choose her courses. As part of a senior transition project during the past two weeks, Johnston has been shadowing a computer programmer, Charles Paclat, and took an online course, which she enjoyed.

“I am excited to take classes I am passionate about,” said Johnston.

And with her future in sight, Johnston won’t forget the help others have given her.

“Thankfully, the teachers and administration at Cape Elizabeth have been extremely helpful and were always there for me, doing whatever they could to help me,” she said.

Isabel Johnston of Cape Elizabeth has overcome many obstacles to become part of Cape Elizabeth High School’s graduating class.