By Srushti Rana, Farooq Ali Khan, Abhishek Kumar, Raamesh Gowri Raghavan, Somdatta Karak, and Sukant Khurana:
Attention deficit-hyperactivity disorder (ADHD) is characterized by the inability to marshal and sustain attention, modulate activity level, and moderate impulsive actions. The result is maladaptive behaviours that are inconsistent with age and developmental level. Three types of ADHD are diagnosed: combined inattentive, hyperactive, and impulsive (about 80% patients); predominantly inattentive (about10–15 percent) and predominantly hyperactivity and impulsive (about 5%). ADHD is a condition which is almost always associated with poor academic performance. Several studies have revealed that the development of anti-social personality as co-morbid with ADHD. Early identification and intervention of this multifactorial neuro-psychiatric condition in children will help them improve their academic performance and also prevent the development of co-morbid conditions. Recognition that ADHD can persist into adulthood did not occur until the 1970s, and the disorder is not nearly as well studied in adults as it is in children.
ADHD touches people of all ages, including adults, and all races. Among ethnic groups, the frequency is probably highest among African American children and lowest among Hispanic children, with white children being somewhere in between, in the United States alone .
Prevalence clearly varies, with risk factors including age, gender, chronic health problems, family dysfunction, low socioeconomic status, the presence of a developmental impairment and urban living. Current advances in cognitive neuroscience, neuroimaging, and behavioral and molecular genetics have provided evidence that ADHD is a complex neurobiological disorder. Many regions of the brain and several neurotransmitters have been implicated in ADHD. Biologically, the neurotransmitter dopamine has received considerable attention as being relevant to understanding ADHD. Neurologically, the prefrontal cortex seems to be relevant to understanding ADHD. The prefrontal cortex has a high requirement for dopamine, and plays a role in cognitive functions such as executive functions. The prefrontal cortex has many reciprocal connections with other brain regions, including the striatum (caudate nucleus, putamen), cerebellum and parietal cortex. Research has indicated that some of these brain regions are slightly smaller or have decreased activation in people with ADHD.
Other factors that affect ADHD patients are:
– Heredity: Studies show that 25% children have ADHD if at least one relative has ADHD.
– Altered brain functioning and anatomy: Two main neurotransmitters implicated to be involved in ADHD are dopamine and norepinephine. MRI findings in investigation are suggestive of some smaller brain parts in children with ADHD. These studies also document reduced blood flow to the frontal brain that regulates the executive functions.
– Prenatal causes: Mothers’ exposure to different chemicals (during pregnancy? ) is related to the occurrence of ADHD in their children. Smoking, alcohol and drug abuse contribute to the causes of ADHD.
A study conducted by Centers for Disease Control and Prevention (CDC) and the Health Resources and Service Administration (United States of America) found that an estimated 11% US school-aged children received an ADHD diagnosis by a health care provider by 2011. Boys (13.2%) were more likely than girls (5.6%) to have ever been diagnosed with ADHD.
The average age of ADHD diagnosis was 7 years of age, but children reported by their parents as having more severe ADHD were diagnosed earlier.
– 8 years of age was the average age of diagnosis for children reported as having mild ADHD
– 7 years of age was the average age of diagnosis for children reported as having moderate ADHD
– 5 years of age was the average age of diagnosis for children reported as having severe ADHD
Cutting edge in research:
Public health issues in ADHD can be divided into understanding three areas:
– how many children have ADHD and whether they are properly diagnosed
– impact of ADHD in the population
– treatments that are effective and are best for children of different ages and in different communities
CDC also conducts community-based studies to better understand the impact of ADHD. The Project to Learn about ADHD in Youth (PLAY) study methods have been implemented in four community sites. Information from the PLAY study helps us better understand ADHD as well as the needs of children and families living with ADHD.
CDC supports the National Resource Center on ADHD, a program of Children and Adults with Attention-Deficit/ Hyperactivity Disorder (CHADD), which is a Public Health Practice and Resource Center.
Several studies have identified the prevalence of ADHD. However, the major limitation of these studies is that they involve a sample consisting of clinically referred cases. The advantages of the current PLAY study over the previous ones are that it overcomes the above limitation as it consists of community sample. Selection of larger sample from four different schools including a wider age group of children aged between 6 and 11 years makes the sample more representative. This wider sample also enables us to compare the prevalence rates among different ages and to study the age wise distribution of ADHD.
Extremely low birth weight (less than 1kg) and environmental conditions such as excessive lead in the air and head trauma (brain injury) are also associated with symptoms of ADHD.
Symptoms of ADHD included in Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV):
– Fails to attend to details
– Difficulty sustaining attention
– Does not listen
– Difficulty organizing tasks
– Avoids tasks requiring sustained mental effort
– Often loses things
– Distracted by external stimuli
– Leaves seat inappropriately
– Runs about or climbs
– Difficulty playing quietly
– Talks incessantly
– Blurts out answers
– Difficulty awaiting turn
ADHD symptoms can appear as early as between the ages of 3 and 6 and can continue through adolescence and adulthood. Symptoms of ADHD can be mistaken for emotional or disciplinary problems or missed entirely in quiet, well-behaved children, leading to a delay in diagnosis.
Evidence from neuropsychological, pharmacologic, and brain-imaging studies implicates dopamine and norepinephrine neurotransmitter system in frontostriatal circuitry in the pathophysiology of the disorder . Genetic factors appear to play an important role . The diagnosis of ADHD requires the identification of specific behaviors that meet the criteria of the DSM-IV-revised.
– Child and Adolescent Behavioral Inventory (CABI) is a questionnaire designed to collect information from parents of children and adolescents, both for preparation of screening and epidemiological studies and for clinical evaluation . In the clinical population, scores at CABI were in agreement with clinical evaluation in 84% cases for depressive symptoms (compared to CBCL 66%), 53% for anxiety symptoms (CBCL 42%) and 87% for ODD (CBCL 69%), differences, however; without statistical significance (chi square).
– Vanderbilt Scales: The Vanderbilt ADHD Assessment Scale is a narrow-band tool that assesses four conditions associated with attention deficit disorders — inattention, hyperactivity/impulsiveness, a combination of the two, and oppositional defiant disorder.
– Conner’s Abbreviated Rating Scale (CARS) consists of several behavioral parameters for the diagnosis of ADHD. This was rated by the parents and the teachers.
– Children’s Behavior Questionnaire (CBQ, Rutter) was given to teachers of children identified in the study as having ADHD. It consists of two separate questionnaires, namely (i) CBQ-A, (ii) CBQ-B. CBQ-A is used for assessing their academic performance, reading and writing difficulties, and need for psychiatric guidance, and CBQ-B is used for assessing their behavioral difficulties, if any.
The most common type of medication used for treating ADHD is a stimulant. Although it may seem unusual to treat ADHD with a medication that is considered a stimulant, it works because it increases the brain chemicals dopamine and norepinephrine, which play essential roles in thinking and attention.
A few other ADHD medications are non-stimulants. These medications take longer to start working than stimulants, but can also improve focus, attention, and decrease impulsiveness in a person with ADHD. Doctors may prescribe a non-stimulant when a person has bothersome side effects from stimulants; when a stimulant was not effective; or in combination with a stimulant to increase effectiveness.
Psychotherapy also helps in coping with ADHD. Behavioral therapy is a type of psychotherapy that aims to help a person change his or her behavior. It might involve practical assistance, such as help organizing tasks or completing schoolwork, or working through emotionally difficult events.
– Reviewed treatments include the non-stimulant atomoxetine, three novel extended-release (XR) stimulant preparations: dexmethylphenidate, lisdexamfetamine dimesylate and the methylphenidate transdermal system (TDS), and the recently approved XR α2-adrenoceptor agonist, guanfacine.
– Lisdexamfetamine (lysine cleaved from d-amfetamine) was the first stimulant treatment approved as a prodrug, absorption generally resulting in up to an 11- to 13-hour benefit.
– Dexmethylphenidate XR is a stimulant treatment in a single isomer form, and has an efficacy and tolerability similar to two doses of immediate-release (IR).
– The methylphenidate TDS patch utilizes skin absorption to provide predictable and uniform delivery of methylphenidate when worn for 9 hours/day or osmotic-controlled release oral system (OROS®) methylphenidate, each provides benefit for about 11–12 hours. The disadvantages of TDS are frequent skin irritation and the need to remember to take the patch off.
– Atomoxetine is the first non-stimulant treatment approved by the FDA and employs weight-based dosing. Atomoxetine is the first non-stimulant treatment approved by the FDA and employs weight-based dosing guanfacine in XR form is the first α2-adrenoceptor agonist to gain approval to treat ADHD, approved for the treatment of 6- to 17-year olds.
The first challenge is related to the clinical complexity of the cases themselves; the vast majority of people with ADHD, both child and adult, have a comorbid psychiatric disorder (such as anxiety, depression, etc).
In the presence of significant comorbidity, complex combined treatments may be required, and the results may be frustrating. Diligent attempts to clarify the co-occurring conditions and related features (for example, poor social skills, low academic abilities) become essential in cases resistant to treatment.
Key public health questions yet to be answered include
– What are the causes, and the factors that increase the risk or severity of ADHD?
– How many children have ADHD? Is the rate increasing?
– How many children have ADHD and other conditions at the same time?
– What social and economic impacts does ADHD have on families, schools, the workforce, and the judicial and health systems?
– Are ADHD and other co-occurring conditions conditions being appropriately diagnosed and treated?
– Are people with ADHD able to access appropriate and timely treatment?
– How effective are the treatments and what are their long-term effects?
Sample case studies of ADHD:
This is a cross sectional study of school aged children selected from four different schools in Coimbatore district, India. Seven hundred seventy children aged between 6 and 11 years were selected from four schools in Coimbatore district after obtaining informed consent from their parents. The presence of ADHD was assessed by using Conner’s Abbreviated Rating Scale (CARS) given to parents and teachers. This is a rating scale that consists of several behavioral parameters for the diagnosis of ADHD. This was rated by the parents and the teachers). The children identified as having ADHD were assessed for the presence of any co-morbid factors by administering Children’s Behavioural Questionnaire (CBQ) to the teachers and Personal Information Questionnaire to the parents (Children’s Behavior Questionnaire (CBQ, Rutter) This questionnaire was given to the teachers of the children identified in the study as having ADHD. It consists of two separate questionnaires, namely (i) CBQ-A, (ii) CBQ-B. CBQ-A is used for assessing their academic performance, reading and writing difficulties, and need for psychiatric guidance, and CBQ-B is used for assessing their behavioral difficulties, (if any).
Results: The prevalence of ADHD among primary school children was found to be 11.32%. Prevalence was found to be higher among the males (66.7%) as compared to that of females (33.3%). The prevalence among lower socio-economic group was found to be 16.33% and that among middle socio-economic group was 6.84%. The prevalence was highest in the age group 9 and 10 years.
The case story presented here is about a 42-year old woman, facing marital issues. The patient’s child had been diagnosed of ADHD in his or her adolescence. Some important symptoms that were noted during her first visit to the psychotherapist:
– Speech issues
– Difficulty in school
– Inattention and disorganized
– Sketchy and sloppy work
– Memory issues
– Tardiness, can’t reach a meeting on time
– Restless of routine and monotonous surroundings (changes the home décor every 2 weeks)
– Not social
– Smokes 2 packs every day, slowing down on alcohol, caffeinated coffee all day, used to do drugs in college
– Lost interest in everyday activities, and the things she used to have interest in prior to diagnosis
These are signs and symptoms that would suggest the diagnosis of ADHD in this adult patient, but not all of them appear in the DSM-IV. The physician feels that the patient fulfills the DSM–IV diagnostic criteria more than well enough to make the diagnosis of ADHD. When this is explained to the patient she protests, having heard that ADHD is treated with “speed,” one of many drugs she had tried and given up in college. Psychiatric comorbidity is much more common in adults than in children, further muddying the diagnostic waters. The majority of adults with ADHD will have one of these concomitant diagnoses: an anxiety disorder; a mood disturbance, including dysthymia, major depression, or bipolar disorder; an antisocial disorder; or a substance use disorder.
Did the therapy help?
The patient was put on stimulants that are approved by the FDA. The patient and the husband both agreed that for the first time for as long as they could remember the patient did not go out for a smoke during dinner or during a movie. It was also seen that she was more patient with children, with support of her husband who made sure she doesn’t miss a dose. Being on therapy for a few weeks (which also involved changing medications in the time), the patient is said to have improved her emotional quotient as well, and exclaimed that “she might even quit smoking”. Apart from the medication prescribed to her, the patient is also dedicated to an exercise program which has helped her shed a few pounds. To help with the marital problems, the physician has advised the couple to see a marriage counselor.
Noteworthy observations while dealing with adult ADHD patients:
It is necessary to keep a check on cardiovascular activities such as heart rate and blood pressure, since it wouldn’t be clinically significant. For co-morbid ADHD patients, stimulants usually induce tic-disorders. Hence, if the situation is said to worsen, non-stimulants are advisable.
ADHD is a difficult diagnosis to make accurately, not only because of the many comorbid conditions, but also because of the real lack of specificity of the symptoms. And along with drug treatments, a lot of behavioral therapies that have also shown to increase effectiveness and hence, are usually a part of the treatment procedure.
Dr. Sukant Khurana runs an academic research lab and several tech companies. He is also a known artist, author, and speaker. You can learn more about Sukant at www.brainnart.com or www.dataisnotjustdata.com and if you wish to work on biomedical research, neuroscience, sustainable development, artificial intelligence or data science projects for public good, you can contact him at firstname.lastname@example.org or by reaching out to him on linkedin https://www.linkedin.com/in/sukant-khurana-755a2343/.