Jasmine Anderson always wondered if she was on the spectrum, though autism in women historically has been considered uncommon. When her 2-year-old son began exhibiting traits such as stimming—typically defined as repetitive or unusual body movement or noises—meltdowns, sensory difficulties and intense aversion to change, she knew.

"Seeing him experience these things triggered memories of myself also experiencing and doing these things," said Anderson, of Glasgow, Scotland. "It began to click that I may be autistic, too. When I looked at my life as a whole, there had been other things, such as extreme anxiety walking into a room of people, feeling overwhelmed by noise, smells and sounds, feeling like I was different from everyone else, and studying them and staring at them intensely so I could mimic their behavior, so I'd know what to do in social situations to get by."

According to Wendela Whitcomb Marsh, a board-certified behavioral analyst in Salem, Oregon, and author of "Recognizing Autism in Women and Girls," autism spectrum disorder (ASD) consists of a group of behaviors and