There has not been enough studies to answer this question with an absolute.  There are studies that show significant differences in the two as well as similarities.
     ADD/H according to studies done seems to have symptoms that describe behaviors reflective of hyperactivity, impulsivity, impulsivity, or both; inattentive behaviors are referred to specifically in only approximately one third of the symptoms.  More behavioral problems occurred in kids with ADD/H whereas with ADD/WO it seemed to be an increase of cognitive difficulties such as reading disabilities.  Children with ADD/H showed to be more impulsive than ADD/WO children.  ADD/H may classify  along the Externalizing dimension whereas the ADD/WO may classify along the Internalizing dimensions.  There is a question of the possibility that ADD/WO is a more attentional / cognitive / anxiety type of disorder in contrast to the more attentional / behavioral / impulsive aspects of ADD/H.
     A study by Dykman suggested that ADD/WO tend to have problems completing class work or homework that was not due to poor achievement.  Another study done by Barkley also showed this but included both groups  to have problems as underachieving, having impaired learning, and having problems with incomplete work.  It was suggested by Hynd and Lorys that that the problem with poor school performance among children with ADD/H maybe linked to attentional / behavioral problems whereas it appears that poor school performance among children with ADD/WO may be linked to more attentional / cognitive disabilities.
     Neuropsychological distinctions among ADD subtypes were also found by Hynd and Lorys in 1991.  They found that ADD/WO children were slower than ADD/H  children in responding to tasks requiring them to name familiar alternating stimuli as fast as possible.  Many of the same findings by others also showed a lack of automaticity of math facts for ADD/WO children based on latencies in solving math  facts.  Another by Lahey showed  a sluggish tempo among children with ADD/WO.  He also found neurocognitive distinctions between the two subtypes.  ADD/WO demonstrated sensory - localization deficits, which are thought to be associated with parietal lobe functioning.  Goodyear found further distinctions on word retrieval measures and on specific reading skills.  Both groups had similar total scores on a word retrieval task but demonstrated qualitatively different performances. The ADD/WO group required significantly more word retrieval cues to achieve a performance similar to that of the ADD/H group.  ADD/WO unlike those with ADD/H, showed an inconsistent pattern in the development of reading skills with word - attack skills exceeding word identification skills.  ADD/WO subjects were also slower in information processing.
     The age difference between the two, in my opinion, is not significant enough data to determine anything between the two, due to the fact that children with ADD/WO a lot of times are diagnosed later than ADD/H children which show behavioral problems that tend to create more stress for adults around them.
 Research has revealed that diagnoses of learning disabilities frequently co-owner among ADD/WO but not necessarily among ADD/H children.  Shaywitz reported from his study that an estimated 10% of children with ADD are also learning disabled.
 There is also a difference in the social life of these two subtypes.  ADD/WO are more likely to be withdrawn socially, where ADD/H tend to be rejected by peers.  Medical treatments also showed some difference.  ADD/H seemed to respond to methylphenidate, while those with  ADD/WO showed higher rates of nonresponse to medication.
     Another study done on learning and language showed children with ADD/H and ADD/WO had similar rates of learning disorders and of problems in language comprehension, language expression, and auditory processing.  There was a difference though shown in the ADD/H children - most manifested some type of speech or language disorders, 20% having pure  speech disorder, and only 10% have pure language disorder.
     After reviewing the information provided on the two subtypes, I believe the two are possibly different disorders which may have started the same but one branching off in another direction.  I feel that they should remain separate in the diagnosing until further research has done to show otherwise.
 
 

Research Questions:

1. Is there a possibility that ADD/H evolved from ADD/WO or vice versa?

2. How are adults, that are successful, that have one of these disorders, managing  their life or compensating in the specific areas that are lacking?
 
 

Discussion Questions:

1. Why is there concearn about sibblings of ADD/H especially if they are girls , in  being tested for the possibility of ADD/WO?

2. If ADD/WO children are less likely to respond to methylphenidate, what form of  medication do they respond to, if any?
 
 

Home	Living as an adult with ADHD	All in the Family?
	A Frustrated Mother	Treatment may prevent substance abuse!
CHADD	ADHD Owner's Manual	ADHD News

Free	Fisherman's Kit Everyone has dreamed of landing the "big one", then what? Dealing with your dream fish just got easier. With this great kit you can  remove the hook and take care of your catch faster and with less hassle than ever before.  This kit includes all the tools needed to make your fishing trip complete.  And this is Free! Click here for yours today!	Click for beauty products Click Here	Live a healthy life with VERIUNI nutritionals.  Tasty liquid multivitamin ensures you'll get nearly every daily nutrient required for prolonged health.  Powerful antioxidant unleashes the power of red wine extract and polyphenols  for the ultimate mind and body energizer. All-natural ingredients. No sugar or artificial preservatives. For more information, check out: http://www.ezinfocenter.com/7320672 /VNU