BOSTON — Several inspiring people with autism and their families were profiled on Katie Couric’s show this summer. It was wonderful to see part of a talk show dedicated to educating people on what it is like to live with autism. But part of the autism spectrum wasn’t shown — the part almost never seen in mainstream media. Where are these people?

I am a parent of a child with autism, and I am lucky. My son received the support he needed when he needed it and falls into the part of the spectrum known as “high-functioning.” He has developed coping mechanisms to deal with his anxiety and sensory challenges. He has learned to tolerate some flexibility when his routine is disrupted. Most important, he is now able to share his extraordinary intelligence, his endearing personality and his unique social conscience.

My son’s story is one of hope, not unlike the stories regularly broadcast on television, printed in magazines or making the rounds on YouTube.

Yet the autism spectrum is wide and diverse, and many who suffer from severe autism will never reach the level of functioning that my child has achieved. Although these people are also part of the story, we rarely hear their stories.

These people react so severely to sensory stimulation that they will seriously injure themselves as a way of relieving the stress. They are often nonverbal. Some require headphones streaming soothing music in their ears just to leave their regular environment for a short time.

Children and adults with autism this severe exhibit behaviors in public that mainstream society views as completely inappropriate. They mumble or yell involuntarily. They may reach out and grab a stranger’s hand or stroke someone’s hair.

I am not referring to people with nonverbal autism who have average or above-average IQs — those who possess the cognitive ability to communicate but whose bodies betray them. Computer applications and other technology can help these people communicate and do many of the things anybody else does, if a little differently.

Instead, those whose stories I’m missing do not have the intellectual ability for communication. Their IQs fall into the severely or profoundly impaired range. These are people who will never read or write or type. They’ll never graduate from high school; they’ll likely never marry or hold a job.

When I advocate autism awareness, it’s this hidden spot on the spectrum that I champion.

No one disputes the incredible importance of early intervention — the program of beneficial therapies started well before age 5 — and continued social-skills training and support within the educational system. Certainly much more work can be done for all people who struggle with autism.

But when I fantasize about finding a cause and a cure, when I dream about a wonder drug that could reverse the effects of autistic disorders, I don’t think about my son or others like him. I think about those at the bottom of the spectrum — their daily struggle and that of their families.

The world is slowly becoming more aware and more tolerant of those who live with autism, but to understand the breadth and diversity of the spectrum, and the impact of living with these disorders, we must see the entire range, not just the hopeful, inspirational stories.

We must see the pain of a parent who watches her child smash his head against a concrete wall, who throws himself on the floor of a store because he simply cannot stand the fluorescent lights another second; the person who starts violently screaming because the crowd getting off the subway terrifies him. We must feel the anguish of compassionate caregivers when everyone around is staring at their loved one with horror and judgment.

We must comprehend the grief of parents who are forced to acknowledge that their children may never be able to care for themselves, and we should consider all the future decisions and worry that realization encompasses.

Many personal stories about autism make us smile and renew our faith in humanity. But some stories will make us cry. They should, because autism can also be terrifying and hopeless. This side of the spectrum still lurks mostly in the shadows. But to fully understand why we search so exhaustively for answers and doggedly seek a cure, these stories must be seen and heard, too.

Amy Mackin is a writer in the Boston area. She blogs at www.amymackin.com.