ADHD children not coming to attention of doctors

The report suggests that many patients ADHD patients are adversely affected because physicians are sticking with older immediate release, short duration drugs rather than a number of newer long-acting therapies that are on the market.

Hugely undiagnosed

Datamonitor estimates that 23 million children and adolescents across the seven major pharmaceutical markets suffer from ADHD, a physician perceived prevalence rate of about 15%. However currently only 12% of those, or only 1.8% of children in the total population, are actually correctly diagnosed with ADHD.

Although these figures are higher than those previously reported, they do indicate that a huge proportion of patients remain undiagnosed and therefore untreated.

Although societal and clinical awareness of ADHD is ever growing, there are still significant gaps between knowledge, recognition and referral of the disease at all points of the diagnostic chain.

What is known is that ADHD is a heterogeneous disorder, with no known etiology and that it appears to be slightly more prevalent in adolescents than children. However, recent research is starting to piece together the primary contributing factors including structural abnormalities, genetic predisposition and neurotransmitter dysfunction.

The two most widely used classification systems defining hyperactivity disorders are the American Psychiatric Association's (APA) Diagnostic and Statistical Manual of Mental Disorders IV (DSM-IV), and the International Classification of Disease of the World Health Organization (ICD-10), which classify the disorders as ADHD and hyperkinetic disorders (HKD), respectively.

The DSM-IV lists 18 symptoms of ADHD, which can be divided into three subtypes: predominantly inattentive, predominantly hyperactive-impulsive, and the combined type, in which the patient must fully meet the criteria for both of the other two subtypes. Additionally, symptoms causing clinically significant impairment must be observed in at least two settings, such as school and home, with onset of symptoms before the age of seven, lasting for at least six months.

Basic symptoms of ADHD classified as inattentive include a failure to attend to details, difficulty in sustaining attention, losing things and avoiding sustained effort. Symptoms considered hyperactive include fidgeting with hands and feet, leaving the seat in the classroom, running and climbing about and an inability to play quietly.

Obviously a child or adolescent suffering from ADHD would find it difficult to achieve in a classroom environment, and therefore risks being left behind its year-group academically and socially. Furthermore, Datamonitor's research indicates that 43% of physicians perceived that teachers are not aware of ADHD.

Stimulating recovery

Historically, the stimulants, including methylphenidate- and amphetamine-based drugs have formed the bulk of pharmacological therapy for the treatment of pediatric and adolescent ADHD. Stimulants work by enhancing the transmission of catecholamines, by blocking dopamine and noradrenalin reuptake transporters. The resultant effect leads to an increase in attention and decrease in impulsivity.

However these immediate release, short duration of action drugs usually required a three-times daily dosage regime, which was problematic (especially for schoolchildren) because stimulants are controlled substances. But the refomulation of these drugs as modified release allows for equal efficacy plus the convenience of a once-daily dosage.

Second generation stimulants like Metadate CD, Ritalin LA have a duration of action of six to eight hours, while Concerta and Adderall XR have an effect over a 10 to 12 hour period. The convenience of the once-daily dosage also helps remove some of the social stigma associated with ADHD.

Despite the availability of numerous longer-acting therapies, currently only 20% of newly diagnosed patients receive such drugs as a first-line treatment, falling to 3% at second-line. Immediate-release drugs are often rated superior to their modified release versions, and physicians rate the convenience of a once-daily dosage strategy as a low priority.

Manufacturers therefore need to promote the benefits of once-daily formulations which provide increased compliance, smoother drug profile and reduced social stigma; features that will significantly improve patient quality of life.

Related research:

·          Stakeholder Insight: ADHD - Prescriber Attention Still Held by Short Acting Stimulant Drugs

·          Adult ADHD - Strattera Grows Up

·          Maximizing Product Returns Through Reformulation: Old Molecules, New Opportunities