For many people, the teenage years are filled with angst, self-consciousness and a general dissatisfaction with life. Surging hormones, changing bodies and a constant yearning for independence can make for one big, uncomfortable swirl of confusion. At least no teen goes through it alone. Their friends are experiencing the same things. But what about those who don’t have much of a social life?

It’s probably no surprise that teens with autism, Asperger syndrome or other autism spectrum disorders have less-than-typical social lives. But a study recently published in the journal PLoS One shows that when it comes to some common social occurrences, these teens fall behind even those who suffer from mental retardation, learning disabilities or speech and language impairments. Kids with an autism spectrum disorder are about half as likely as kids with these other disabilities to hang out with friends outside of school, get a phone call from a friend or receive an invitation to a social activity.

The study authors also noted that a majority of autistic teens don’t participate in activities like sports, clubs or scout groups. Non-school socialization was lowest for autistic teens with the worst communication and conversation skills, and for those whose families had the lowest incomes. While autistic teens may have quality social interactions at school, they need friends outside of school, too.

Experts say Healthy friendships are important for anyone because they can reduce stress, help people cope with tough times, promote happiness and fight loneliness and depression.

Information about autistic teens’ social lives can help health-care providers and others understand how to improve the kids’ opportunities for interactions outside of school, and maybe even help them become better at socializing in the first place.