Excessive use of computer games among young people in China appears to be taking an alarming turn and may have particular relevance for American parents whose children spend many hours a day focused on electronic screens. The documentary “Web Junkie,” to be shown next Monday on PBS, highlights the tragic effects on teenagers who become hooked on video games, playing for dozens of hours at a time often without breaks to eat, sleep or even use the bathroom. Many come to view the real world as fake.

Chinese doctors consider this phenomenon a clinical disorder and have established rehabilitation centers where afflicted youngsters are confined for months of sometimes draconian therapy, completely isolated from all media, the effectiveness of which remains to be demonstrated.

While Internet addiction is not yet considered a clinical diagnosis here, there’s no question that American youths are plugged in and tuned out of “live” action for many more hours of the day than experts consider healthy for normal development. And it starts early, often with preverbal toddlers handed their parents’ cellphones and tablets to entertain themselves when they should be observing the world around them and interacting with their caregivers.

Read the article “Screen Addiction is Taking a Toll on Children” on mobile.nytimes.com.