Attention-deficit/hyperactivity disorder (ADHD) in the course of life

Estimated prevalence and incidence of diagnosed ADHD and health care utilization in adults in Sweden - a longitudinal population-based register study

BACKGROUND

Although the worldwide prevalence of attention-deficit/hyperactivity disorder (ADHD) in adults is estimated to be between 2% and 5%, it is considered to be underdiagnosed. This register study explored the prevalence of diagnosed ADHD and incidence of newly diagnosed ADHD in Swedish adults over time, and assessed comorbidities and pharmacologic treatment.

METHODS

National Patient Register data were used to estimate the overall prevalence of adults (≥18 years) with a registered ADHD diagnosis from 2006 to 2011, and the incidence of newly registered diagnoses from 2007 to 2011. Data from the Prescribed Drug Register were used to estimate the mean dose of the most frequently prescribed ADHD medication.

RESULTS

The estimated annual prevalence (N=44,364) of diagnosed ADHD increased from 0.58 per 1,000 persons in 2006 to 3.54 per 1,000 persons in 2011. The estimated annual incidence of newly diagnosed ADHD (N=24,921) increased from 0.39 per 1,000 persons to 0.90 per 1,000 persons between 2007 and 2011. At least one comorbidity was diagnosed in 52.6% of adults with ADHD (54.0% of newly diagnosed adults), with anxiety, substance use disorders, and depression being the most common. Among all adults with ADHD, 78.9% (65.7% of newly diagnosed adults) were prescribed ADHD medication and one-third were prescribed more than one add-on medication. Osmotic release oral system methylphenidate was the most commonly used medication. The mean daily dose was 51.5 mg, and was significantly higher in males, patients with substance use disorders, patients with drug holidays, and patients with at least one add-on medication. The most frequent concomitant medications were anxiolytics and hypnotics.

CONCLUSION

In Sweden, the number of adults diagnosed with ADHD increased between 2006 and 2011, and the majority of patients were prescribed ADHD-specific medication. Over one-half of patients had psychiatric comorbidities; one-third were prescribed more than one add-on medication. Consumption of pharmacologic ADHD medication was high in specific patient subpopulations.

Dysfunctional cortical inhibition in adult ADHD: neural correlates in auditory event-related potentials

In recent times, the relevance of an accurate diagnosis of attention-deficit/hyperactivity disorder (ADHD) in adults has been the focus of several studies. No longer considered a pathology exclusive to children and adolescents, and taking into account its social implications, developing enhanced support tools for the current diagnostic procedure becomes a priority. Here we present a method for the objective assessment of ADHD in adults using chirp-evoked, paired auditory late responses (ALRs) combined with a two-dimensional ALR denoising scheme to extract correlates of intracortical inhibition. Our method allows for an effective single-sweep denoising, thus requiring less trials to obtain recognizable physiological features, useful as pointers of cortical impairment. Results allow an optimized diagnosis, reduction of data loss and acquisition time; moreover, they do not account exclusively for critical elements within clinical evaluations, but also allow studying the pathophysiology of the condition by providing objective information regarding impaired cortical functions.

Assessment of post-excitatory long-interval cortical inhibition in adult attention-deficit/hyperactivity disorder

In order to further examine cortical impairment in adult ADHD patients and to test the hypothesis of a disturbed neuronal inhibition in adults with ADHD, late auditory evoked potentials were measured. By using paired-chirp auditory late responses, we compared 15 adults with ADHD with 15 control subjects, focusing on the inhibition elicited by the stimuli. Besides amplitude measurements, a time-frequency phase coherence study using the wavelet phase synchronization stability (WPSS) was performed. ADHD was diagnosed according to DSM-IV criteria. All ADHD subjects were without medication and did not suffer from any further axis I disorder. WPSS analysis revealed impaired auditory inhibition for ADHD patients for interstimulus intervals (ISI) between 500 and 1,100 ms as compared with healthy controls. By analyzing the WPSS in the interval from 80 ms to 220 ms, mean inhibition of the test chirp was found to be 6% in the ADHD group and 38.5% in the control subjects (p = 0.01). Moreover, overall smaller amplitudes in the N100 and P200 waves at all ISI were found (p = 0.04 and p = 0.02). However, reproducibility indices in the amplitude measurements were low, thus supporting the use of the instantaneous phase-based analysis method. The results support the hypothesis of reduced intracortical inhibition as a correlate of disturbed brain function in adults with ADHD.

Distinguishing comorbidity and successful management of adult ADHD

OBJECTIVE

Given high rates of comorbidity, lack of awareness and global acceptance, and varying guidelines for its management, adult ADHD may be an especially difficult condition to diagnose and treat. The objective of this review was to explore and characterize similarities and differences among comorbidities associated with adult ADHD.

METHOD

A review of the literature over the past 10 years was performed using Ovid.

RESULTS

A myriad of comorbid conditions such as impulse-control/personality, anxiety, mood, substance use, learning, and sleep disorders overlap with adult ADHD. Furthermore, a number of such conditions have symptoms that can mimic those of ADHD, including hyperactivity, impulsivity, inattention, and disruption of circadian rhythms, adding to the complexity of recognition and diagnosis of ADHD in adults. Extensive research shows that adults with ADHD appear to benefit from treatment with stimulant medications in similar ways as children, including significant improvements on driving performance. However, fear surrounding the abuse of stimulants is an important issue. Nevertheless, evidence suggests that children with ADHD who are treated with stimulant medication are less likely to develop a substance use disorder in adolescence and adulthood.

CONCLUSION

There are a wide range of comorbidities with adult ADHD with many having overlapping symptoms. The benefits observed with ADHD treatment, however, emphasize the importance of recognition and treatment of adult ADHD.

ADHS im Jugendalter

Ausgehend von der Betrachtung der ADHS als Lebensspannenerkrankung geht die vorliegende Studie der Frage nach, inwieweit Symptome einer adulten Aufmerksamkeitsdefizit-/Hyperaktivitätsstörung (ADHS) bereits im Jugendalter auftreten und Folgen für die klinische Praxis haben. Auf der Basis einer Repräsentativdatenerhebung wurde eine Stichprobe von N = 140 Jungen und Mädchen im Alter zwischen 14 und 19 Jahren erhoben. Mittels der eingesetzten Verfahren ADHS-E, SF-12, SWLS und PHQ-15 und PHQ-9 wurden Zusammenhänge zwischen den ADHS-Symptomen im Erwachsenenalter und Lebenszufriedenheit bzw. Lebensqualität über psychische und körperliche Symptome bei Heranwachsenden untersucht. Dabei konnte die ADHS als ein wesentlicher Faktor für die Beeinträchtigung der Lebenszufriedenheit und Begünstigung von Depressivität in der Adoleszenz ausgemacht werden. Für die klinische Praxis ergibt sich daraus ein veränderter Blickwinkel auf die Lebenszufriedenheit von Jugendlichen im Allgemeinen und auf zusätzliche psychische Belastungen im Rahmen einer adoleszenten Form der ADHS im Besonderen.

Attention deficit/hyperactivity disorder: a review and update

Attention deficit/hyperactivity disorder (ADHD) is a prevalent, chronic, and pervasive childhood disorder characterized by developmentally inappropriate activity level, impulsivity, and inability to sustain attention and concentration. Core symptoms of the disorder are associated with impairment in multiple domains of functioning and often coexist with other psychiatric disorders, the most prevalent being oppositional defiant disorder, conduct disorder, depression, and anxiety disorders. Concerns have been expressed about the overdiagnosis of ADHD, an upsurge in prescription of stimulant medication, and wide variations in practice patterns related to diagnosis and treatment of children with ADHD among primary care providers. Clinical research and expert consensus guidelines over the past decade have increasingly clarified the most effective approaches to diagnosis and treatment of the disorder. Hence, the purpose of this article was to provide primary care providers with the most current, evidence-based information on the assessment and treatment of children with ADHD.