Attention Deficit Disorder (ADD) is a subtype of Attention Deficit Hyperactivity Disorder (ADHD), and has certain distinguishing features that make it easily identifiable in clinical practice. From a broad perspective, ADD is basically ADHD without the associated hyperactivity. These days it is considered a redundant term, but it is sometimes still used in clinical practice.
ADHD is classified into 3 main types based on the predominant symptoms - Inattentive type, hyperactive-impulsive type and the combined type. The impulsive type is also called ADD, as it lacks the hyperactivity component to it.
ADD is believed to arise from changes in the parietal lobe of the brain, which lies on the side of the brain. The hyperactivity component that is seen in ADHD is often due to involvement of the part of the brain that lies on the front, called the frontal lobe. Research has shown that this component of ADHD may be related to release of certain chemicals in disproportionate amounts in the brain.
In ADD, patients are often inattentive, have short concentration times and overall low energy levels. They tend to avoid long discussions and can be confused on occasions. Patients are easily distracted as well. Children who suffer from ADD tend to daydream a lot, and often lose their things. Poor performance at school may also be a feature. Adults present with similar symptoms, and they tend to be unable to maintain a job, changing professions often.
On the other hand, patients with ADHD have the above described symptoms (sometimes), along with excessive activity and inability to sit still in one place. Patients also tend to get bored easily and often present with inappropriate behaviour when in social situations. Patients with the combined type of ADHD exhibit features of hyperactivity and impulsivity along with lack of attention. This type is believed to be the most common type of ADHD.
In some occasions, there are overlapping symptoms that make differentiating the two conditions a bit tricky. However, in the hands of an expert, these features become a lot clearer and optimal treatment can be offered.
Diagnosis of these two conditions is primarily from history. The presenting features are fairly typical, and often a number of different questions will need to be asked to make the right diagnosis.
Treatment options are not particularly different between ADD and impulsive type ADHD, as they are the same condition. Treatments are individualised depending on the presentation, and hyperactive patients require different treatments to impulsive ADD patients.
ADD is a subtype of ADHD, though it represents the inattentive type of ADHD. Treatment depends on the presentation, and diagnosis is primarily obtained from clinical history.