Is it Attention Deficit Disorder when people only pay attention to things that interest them?

With regards to your question, ADD is a subtype under the broader category of ADHD (attention deficit hyperactivity disorder) that is characterized by inattention, distractibility, disorganization, and forgetfulness. It may be seen in adults (or even children) who do not present with the hyperactivity features of ADHD more commonly seen in the pediatric population. The features of ADD, as defined in the DSM IV are the following:

1. Six (or more) of the following symptoms of inattention have persisted for at least six months to a degree that is maladaptive and inconsistent with developmental level:

Often fails to give close attention to details or makes careless mistakes in schoolwork, work, or other activities
Often has difficulty sustaining attention in tasks or play activities
Often does not seem to listen when spoken to directly
Often does not follow through on instructions and fails to finish schoolwork, chores, or duties in the workplace (not due to oppositional behavior or failure to understand instructions)
Often has difficulty organizing tasks and activities
Often avoids, dislikes, or is reluctant to engage in tasks that require sustained mental effort (such as schoolwork or homework)
Often loses things necessary for tasks or activities (eg, toys, school assignments, pencils, books, or tools)
Is often easily distracted by extraneous stimuli
Is often forgetful in daily activities

These symptoms must be (1) seen in two or more settings (work, school, home, or other social settings), (2) cause significant impairment in academic, occupational, or social life, and (3) not be better explained by other psychiatric or medical conditions, such as mood disorders, psychosis, schizophrenia, dementia, intoxication, delirium, etc.

I hope this answers your question to your satisfaction.
Best wishes

DISCLAIMER
Though the author of this information is a licensed physician, the information provided above is FOR EDUCATIONAL USE ONLY, and DOES NOT CONSTITUTE MEDICAL ADVICE/OPINION, is not meant to diagnose or treat any illness or disease, and is not a substitute for the medical advice of your (or your loved one’s) primary care physician or other medical professional. While striving to be factual and exact, no warranties are made with regards to the accuracy of the information provided above. You are always advised to talk with your (or your loved one’s) doctor about any health concerns that you have and about any of the information provided above. Sole reliance on the information provided above is not advised and would be solely at your own risk and liability.

My mother is in her 90's. For decades I have noted that she spent a lot of time laying on her bed staring at the ceiling and seemed lost in thought. Often she had (and still has) fixations on some topics. Other topics introduced are either ignored or agitate her (a coping mechanism)? She was diagnosed with vague mental disorders as early as her teens, back when not much could be done. Her "medications of choice" are anti-depressants and alcohol.

I have a child with ADD. Her meds over the years have stimulating effect (best way to describe it). So, to get "focus" the meds speed up rather than slow down (again, best way to describe it). Concerta does well for her.

What I'm asking for opinion on -- is there any benefit to giving an elderly person a med for ADD to calm them rather than the "classic" anti-agitation meds? (eg: Xanax, or Valium) Even at this late stage in her life, I'd appreciate seeing my mother getting the chance to get out of the mind-set she's in, which involves a lot of inactivity and dwelling on things that only make her and others who care for her miserable.

No, ADD is the inability to concentrate or keep on any one track for long. Those with ADD can be all over the place. Many people pay attention only to what interests them. The extreme of this is perhaps what is often seen with Asperger's syndrome. For anyone following the TV show Parenthood, Max's obsession is insects (and recently the vending machine). Anything outside insects tends to bore him.

I should have added that Max is a teenage character with Asperger's on the show. It is about the best depiction of serious Asperger's I've seen on the screen. The actor does an excellent job.

My 76 year old Dad has Attention Deficit Disorder. His conversation is all over the place without his medication. His treating physician continues to prescribe Ritalin for him.

From what I understand, ADD and Asperger's are not on the same spectrum. Perhaps they are genetically related though. My 31 year old son has autism. Asperger's, I believe, is a form of autism.

You are right, Carol. ADD and Asperger's are not related. Asperger's is the higher end of the autistic spectrum. My father probably would have been diagnosed with Asperger's if it had had a name when he was younger. He never had trouble with attention. He could spend hours doing things that would bore most people in a short time. It is almost the opposite of ADD, since the person will have an almost obsessive attention to what interests them. This varies, of course, depending on how the individual is affected by the disorder. (I don't really even know if it is a disorder. It may just be called that because other people see it as odd behavior.)