Dr. Wendy Walsh: Before I could write this blog, I had to nag my 12-year-old for twenty minutes in order to wrangle my computer out of her hands. She was so focused on the various windows she had open -- Facebook and Twitter, accompanied by the background throbbing of an iTunes track.

Clearly, many, many kids spend way too much time in front of their computers and texting on cell phones -- and much of that time is spent social networking. But it that all bad? The answer to that question is a big fat, "Depends."

When adolescents and teens began trolling the World Wide Web for friends (old and new), parents' biggest concern was online predators who might be posing as kids. That concern is still valid, but today, more moms are worried about the psychological, physiological and social implications of all these digital relationships. And there is much to worry about.

As fast as social networks are growing, so, too, is the research. A quick search through some of my favorite scientific sites yielded this handy set of recent data:

• Superficial online relationships can result in feelings of detachment and even contribute to certain health-related problems. Two studies out of the University of Arizona show that hoarding friends on Facebook and Twitter won't stave off loneliness if those relationships lack a strong connection.
• According to the Archives of Pediatrics & Adolescent Medicine, adolescents with psychiatric disorders such as attention-deficit hyperactivity disorder (ADHD), social phobia, hostility and depression may be more likely to develop an Internet addiction. (But which came first, the chicken or the egg?)
• A brand-new, large-scale study out of Great Britain has found that people who spend a lot of time browsing the Internet are more likely to show depressive symptoms.
• My favorite self-report study shows that college students who are forced to abstain from social networking (including texting) experience withdrawal symptoms similar to those of withdrawal from drugs or alcohol. University of Maryland researchers found that most college students are not just unwilling, but functionally unable to be without their electronic links to the world. The students described their withdrawal symptoms not unlike how a drug addict would, using terms such as "frantically craving," "very anxious," "extremely antsy," "miserable," "jittery" and "crazy."

So what's a mom to do? Well, before you throw all computers and cell phones in the trash, here's some rather positive news: According to a new study conducted by University of Virginia psychologists, well-adapted youth with positive friendships tend to use social-networking sites to further enhance the positive relationships they already have.

If you worry that your adolescent or teen might be addicted to social media, now is the time to do some family weaning so they can learn to self-control and use tech stuff more responsibly. In my house, I have four hard-and-fast social-media rules:

1) No social media until all homework and long-term projects have been completed. (Trust me: This is a huge incentive for kids to get their academic work done.)

2) No social media during family dinnertime. Period. I don't care if the most pressing show is airing on TV or if Justin Bieber is debuting his new video on YouTube; if it happens on a screen at 6 PM, it doesn't happen in my house.

3) All media "powers down" one hour before bedtime. That gives the brain a chance to disengage and relax before sleep. By the way, this is a great time to encourage that archaic habit called "reading."

My kids also have one hard-and-fast rule that they have made me adhere to: When they are in the car, I'm not allowed to text, e-mail or talk on the phone -- Bluetooth or no. My job is to focus on the road and referee their fights. And believe me, that's more than enough brain stimulation for any one human being.