Missed yesterday’s discussion on parenting and family relationships? Below is an edited excerpt from Marguerite Kelly’s Q&A with readers. The entire transcript here.

Do you have any suggestions for a 6-year-old boy who bites his nails and toenails? We're especially concerned because he bites the outer layer skin around his nails to the point where it looks like he only has a single layer of dermis to protect him! We've tried the nasty-tasting nail "polish," offering chewing gum (he doesn't want it), keeping his hands busy, etc. Nothing works.

Kelly: The experts say that we can break a habit if we don't practice it for 21 days but nail biting is a hard one to break. Try talking to your son in the dark, so he doesn't have to look you in the eye, and ask him why he thinks he bites his nails and what started it because he may be expressing anxiety that way. Then ask him what he thinks he should do about it and how you could help. If you let him run this part of his life, he may try [harder] to quit. And then give him an ointment, like Neosporin, and tell him to apply it to his finger or his toe if it should ever get red because he wouldn't want it to get infected. This will help him, maybe, and it may also help him if he asks the pediatrician for his advice, but basically, the drive to quit must come from him, not from you.

My daughter and my father are exceptionally close. He lives in a different city and recently had a stroke that has resulted in him being paralyzed and having a speech deficit. When is an appropriate time to take a (quite advanced) 4-year-old to see him? We want [her to] help motivate his physical therapy, but we don't want to really scare or upset her.

Keep your daughter fully informed, so his condition won't be a surprise, and ask the nurse if she can Skype with you at his bedside, so your daughter can see him for herself on screen before she sees him in person. Then you and she can talk about ways to motivate him in his rehab and [get him] back to good or at least better health. Having a goal will help your daughter most.

Hi. My youngest son, 10 years old, is in fifth grade. He was diagnosed with ADHD two years ago and has been on Focalin, Ritalin and now Adderall. At school there was a recent incident where he tried to help a fellow student by sharing something. The student wanted what my son was using, which my son wasn't willing to share, and other students got involved. My son got angry, said some unkind things and started crying. He was sent down to to the guidance counselor to cool off. After school he didn't want to talk to mom and dad because he said thinking about it made him mad. We finally got him to share about what happened because we wanted to hear his side since we heard about what happened from the school counselor.

Why was it so hard to get him to talk to us? He was in therapy with a social worker for the first year of his ADHD diagnosis, but we discontinued it because my son didn't want to go anymore. I have considered getting him to see a therapist again to talk about his anger and frustrations, but he is a child that doesn't want to talk about his troubles. And maybe we should just let him be? As his mom, I'd appreciate any insight and suggestions.

Kelly: Every drug has a side effect, even if it helps with the main problem. I'd do a lot of reading about Adderall, and I'd talk with the chief pharmacist at your drugstore because a good pharmacist knows more about drugs and their side effects than a good doctor, because that's what he worries about all day long while a doctor — even a specialist — is stretched in a hundred different ways. And I'd also read “Anatomy of an Epidemic” and of course, talk with your boy, too, and ask him if he thinks that the drug he is on is really helping him. It might be that instead he needs neurofeedback or meditation to help him handle his ADHD. Check the studies with www.nlm.nih.gov , where all the scientific studies are stored from around the world.