U.S. and U.K. scientists have completed the most comprehensive analysis of the costs associated with supporting a child with an autism-spectrum disorder (ASD) over a lifetime and found that those whose ASD is linked with intellectual disability can accrue up to $2.4 million while those without intellectual disability require about $1.4 million in medical, nonmedical and indirect costs. And that’s on top of the average $241,000 that it takes to raise a child to age 18 in the U.S.

(MORE: Using Movement to Diagnose and Treat Autism)

About 79% of that cost is due to services such as medical care, home health care, special education and after-school care — and 9% is due to wages that caregivers give up to tend to an autistic family member. The latter came as a surprise, says the paper’s senior author, David Mandell, director of the Center for Mental Health Policy and Services Research at the University of Pennsylvania, who points out that not enough of the debate about autism’s toll includes consideration of the indirect consequences of the condition. But, he says, “I think these costs are avoidable by having much better, comprehensive intervention systems and workplace policies that are much friendlier to families with children with disabilities.”

These estimates, published in JAMA Pediatrics, are higher than previous ones, and highlight how diverse the costs of autism can be, from the more obvious medical fees to the hidden economic, social and even less tangible psychological ones.

(MORE: Behavior Therapy Normalizes Brains of Autistic Children)

By comparison, here is how the lifetime cost of autism compares with costs for other conditions (note that figures come from different studies published with data from different years and have been adjusted for inflation. They are for general comparison only).

Lifetime cost Raising child to age 18 years $241,080 Raising child with ADHD + $1,291,000 Raising child with Down syndrome

+ $533,000 Raising child with asthma + $26,000 Raising obese child

+ $19,000 (medical only)

Sources: USDA, Journal of Pediatric Psychology, EPA, Partnership for America’s Success, Pediatrics

Contact us at letters@time.com.