Attention deficit hyperactivity disorder (ADHD) is one of the most commonly diagnosed and recognized psychiatric disorders among school-age children but there seems to be disconnect when it comes to diagnosing adults. William-Orlando (2011) suggest that as many as 10% of children in the United States are diagnosed with ADHD, while Kessler et al. (2006) estimate that 4.4.% of the US adult population has ADHD with only 10.9% in treatment. Though this disorder has been traditionally been diagnosed in children, there has been an ongoing paradigm shift in the field of psychiatry and psychiatric nursing with an alteration in the treatment options across the full range of ADHD symptoms for both children and adults. As healthcare providers, it is essential to understand the diagnostic criteria of ADHD as a neurodevelopmental disorder and educate ourselves in the multidimensional causes, symptoms, and treatment modalities associated with ADHD in children and adults alike.
ADHD consists of a trio of symptoms that are defined by the DSM-5 as inattention, hyperactivity, and impulsivity. According to the DSM-5 (2013), when diagnosing individuals with ADHD, there needs to be a persistent pattern of inattention and/or hyperactivity-impulsivity that interferes with functioning or development with several inattentive or hyperactive-impulsivity symptoms that were present before the age of 12 and symptoms that are present in two or more settings (such as school, work, home, or socially). As a neurodevelopmental disorder, ADHD is caused by a combination of genetics, brain size, gray matter thickness, childhood experiences, environmental factors, and the interaction and distribution of chemical receptors and neurotransmitters. Many of the symptoms present in ADHD are linked with abnormalities of various circuits involving the striatum and the prefrontal cortex, more specifically the dorsolateral prefrontal cortex (DLPFC), dorsal anterior cingulate cortex (dACC), orbitofrontal cortex (OFC) and the prefrontal motor cortex. As one of the most prominent symptoms of inattention in ADHD, inefficient processing in the DLPFC results in executive dysfunction and problems with selective attention. In addition, individuals with ADHD either fail to activate or there exists dysfunction of the dorsal anterior cingulate cortex (dACC). Dysfunction and failure to activate the dACC results in individuals experiencing problems sustaining attention. Impulsivity in individuals with ADHD is linked to the orbitofrontal cortex (OFC) while hyperactivity is associated with the prefrontal motor cortex.
In addition to dysfunction of the PFC and striatum, studies conducted by Shaw, et al (2006) at the National Institute of Mental Health have shown that children with ADHD had smaller total brain volumes (in all four cerebral lobes, including white matter and gray matter, as well as the cerebellum) by approximately 5% compared with controls. In a follow-up study, Shaw (2006) also found that children with ADHD had global thinning of all the gay matter compared with the controls, and there was predominate thinning of gray matter in the PFC. As the individuals from this study grew into adolescence and showed the usual pruning of total gray matter, the children who remained impaired at follow-up had thinner gray matter in the medial PFC at the beginning of the study and children who grew out of the disorder showed a normalization of the gray matter thickness in the right parietal cortex.
There appears to a narrow-mindedness that occurs in psychiatry when diagnosing adults for ADHD, especially since this has been considered a predominantly child disorder. But what happens when the child diagnosed with ADHD grows up—do they simply grow out of the disease as well? Evidence suggests that the young individual with ADHD does not necessarily grow out of the problem, and symptoms tend to persist, although adolescents usually become more goal directed and less impulsive (Cipkala-Gaffin, 1998; Pelham et al, 1998). The presenting symptoms of a child with ADHD vary significantly from those of an adult, and it is the role of the clinician to provide a thorough and substantial analysis of the patient’s presenting symptoms and retrospective assessment to ensure appropriate diagnosis and evaluation. In a review on the diagnosis of adult ADHD, Primich and Iennaco (2012) discuss the risk for misdiagnosis and ineffective treatment because of the presence of symptoms and impairments held in common mood and anxiety disorders. Barkley (1990) writes that while children are typically referred to a clinician for diagnosis of ADHD by school officials and parents, most adult patients self-present which may explain the low percentage of adults receiving treatment for ADHD.
One of the major difficulties that clinicians face when assessing the adult is differentiating and understanding the presentation of inattention, impulsivity, and hyperactivity. Among adults, only 50% report symptoms of hyperactivity–impulsivity while 90% report prominent symptoms of inattention (Wilens & Dodson 2004). The common symptoms of hyperactivity found in children are less prominent in adults and evolve into a sense of inner restlessness, which can be demonstrated by shifting in seat, difficulty relaxing, and an inability to sit throughout a meeting (Primich & Iennaco, 2012). As the individual matures and ages, quantifiable problems that may have existed in their youth and adolescence, as measured by declining school performance, become more difficult to measure due to compensation of deficiencies. Primich and Iennaco (2012) write that direct and collateral information regarding such areas as the quality and character of interpersonal relationships, ability to routinely pay bills on time and keep promises and/or appointments can yield insight into the patient’s profile. Due to the retrospective criteria necessary for diagnosing an adult with ADHD, consulting family and friends of the individual as collateral can be helpful in determining the longitudinal scope of their symptoms and behavior.
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