What do we know about ADHD across the lifespan?
- ADHD is seen in 3-5% of children, and is the most common child diagnosis today.
- about 85% of those cases are boys and 15% are girls; however, Ingersoll argues that these estimates are based mostly on the hyperactive type of ADHD, and the inattentive type is under-estimated.
- there is a 10-35% chance a family member of an ADHD person will have it.
- heritability estimates (the percentage of the trait we think is genetically determined) are higher when based on mother’s reports than on teacher’s reports.
- concordance is 50-80% for identical twins (heritability of 55%), 0-33% for fraternal twins (heritability of 32%), but environmental factors contribute probably 40-50% of the variance.
ADHD or ADD can look very different at different points across the life span:
- Infants that grow up to be hyperactive are often difficult babies, with irregular eating, elimination, and especially sleep habits, as they may need less than other children. They tend to fuss and cry more than they coo and smile, and have difficulty adapting to changes in environments, light, and sound. They were very active even as infants; Ingersoll reports that many parents of ADHD youngsters reported that they kicked and bounced cribs apart, were able to escape from cribs, and were difficult to hold, making feeding and changing diapers a struggle. They may seem to get less enjoyment from cuddling and smiles, and may startle easily.
- Preschoolers show high levels of activity, and clumsiness and awkwardness coupled with a seemingly magical ability to thwart the best of child-proofing efforts is expected. They may seem strong-willed, difficult to discipline compared to other children, and prone to tantrums and crying spells. Likewise, their attention span is short, and while they may have walked early, they may show delays in motor control, toilet training, and speaking.
- During Middle Childhood, the child’s messy, frustrating, and inattentive style is more noticeable given the greater demands for self-control and cooperation made of school age children. Sitting still and remaining seated, waiting turns, and good behavior on field trips, in the hallway, and on the bus are all difficult. Parent-Teacher conferences, calls from parents of peers, and suggestions to “wait another year” before returning to Cub Scouts and sports are common. Stealing and fights may become serious problems. Parents may move into battlefields over homework, getting ready on time for school, and weekend activities. Self-esteem issues develop, as they have fewer friends, don’t understand their won role in peer and adult conflicts, and fall behind in sports, academics, and social skills.
- During Adolescence, symptoms may change. Therapists used to think children outgrew ADHD by adolescence, but most recent research indicates otherwise. Even though the hyperactivity may appear to have subsided, adolescents with ADHD tend to get into more trouble due to their impulsiveness and difficulty thinking ahead. Some have argued that taking Ritalin and other drugs increases their risk to try drugs and alcohol, but this may be more the result of impulsiveness. They may especially have trouble driving, leading to numerous fender benders and tickets. School and homework problems have taken their toll, resulting in failing grades (50% of ADHD teens have failed one grade, and 33% have failed more than one). Failing, lack of social sensitivity at times, and impulsiveness may lead to social rejection and isolation, and that to depression.
Adults are a special case covered in the next paper, ADHD and Adults
What are the common symptoms of ADHD?
Several authors describe the key symptoms of ADHD in both children and adults:
- difficulty ignoring distractions. This is the “key” to understanding ADHD. The disorder is not really an “attention deficit,” as we originally thought, but rather is a deficit in skills to resist distraction. Stimulant medication is thought to aid ADHD people in that it can stimulate the areas of the brain that allow us to ignore outside distractions, other lines of thought, intrusion of memories, etc…
- difficulty controlling impulses and thoughts. They have difficulty ignoring thoughts, fantasies, irrelevant trains of thought… and act before they realize that they haven’t thought things through. They describe it as like having a television in your head that is constantly changing channels. This “channel surfing” style of thinking makes it very hard to focus on a task. Sudderth and Kandel point out it can also lead to poor choices about safe sex, spending, and addictive habits like overeating, drinking, and smoking. It can also lead to “zoning out” in a conversation or being distracted by thoughts and ideas, and making others think you are paying attention to them.
- becoming overfocused in some areas. ADHD people can sometimes direct their attention to one area well, but then have difficulty studying or working with multiple forms of information. They are not “multitasking people.” Thus, reading the review questions on the board, listening while another student reads, and then considering answers to the questions on the board is very difficult. It requires keeping track of questions, reading, and listening too. Adults may learn to focus intently on one form of information, and may find minor noises, comments and interruptions from others, or differences in their work setting to be very frustrating. It also means remembering instructions while driving is sometimes impossible, as is keeping track of the time and meeting someone on time after shopping.
- being less responsive to rewards and punishments. This makes sense, in that they tend to spend less time considering their actions and the outcomes before and after acting, and thus need longer to learn from mistakes. However, delaying gratification for a treat, remembering how unpleasant negative outcomes were, and remembering the contingency rules (e.g., “Listen for 30 minutes and get a treat” or “Touch this and get a time out”) are harder.
- trouble noticing signs and posted rules, as well as remembering and remembering when to apply stated rules. They may often engage in behaviors that break a rule without realizing it, or act out in a way that would be acceptable in other situations but not in the current one because they didn’t realize the rules changed. However, no one likes to be nagged, and so when others continually prompt them to pay attention, don’t do something, remember to do something else, sit up, keep track of their things… they are likely to become more frustrated and annoyed, impairing their ability to attend to matters at hand even more.
- trouble applying what they learn in one setting to other settings; thus, teaching them how to manage one kind of task (e.g., figuring out division problems at home) will not necessarily lead to improvement in similar kinds of tasks (e.g., figuring out multiplication problems at school) without additional instruction in those tasks too.
- an impulsivity that impairs organizational skills, and makes holding on to thoughts very difficult. This often leads to blurting out statements, when others would say the client should have thought before they spoke. It also makes it hard to build a “mental filing cabinet” to hold important information for later use. That is in part why ADHD people seem so forgetful.
Which causes of ADHD are supported by evidence, and which are myths?
Bad Parenting: There is little evidence to support this, as ADHD children show problems early in life, across numerous situations, and with numerous adults. Difficult pregnancies, childhood illnesses, learning problems, and various physical and neurological differences are common. Parents may well respond to ADHD children differently, due to their greater negativity and disobedience, and may show more efforts to control and negatively monitor an ADHD child. However, while bad parenting does not cause ADHD, it may exacerbate the impairment it causes.
Sugar and Additives: There is little replicated evidence that ADHD is due to sugar intake, food dyes and additives in food, and allergies. There is more evidence to support some genetic predisposition, with siblings having higher rates of ADHD when one is diagnosed, whether they are raised together or apart by different parents. Other psychiatric issues (like depression, alcoholism, and anti-social behaviors) are also more common in biological relatives of children with ADHD.
Many other ideas have gained some popularity in the past, like carbohydrate intake, viruses, low birth weight (LBW is seen in 22-34% of ADHD kids, but only 8% normal kids), cigarette smoking in pregnant mothers (22% of ADHD children had mothers who smoked a pack a day during pregnancy, versus 8% of normals)…. Bradley and Golden (2001), after a detailed review of the published literature, concluded that there was some limited data on dietary substances, toxins, and allergies, little of it has been replicated. Most ADHD children probably won’t be helped by diet changes. Of course, this is not to say that you can ignore your child’s allergies, that children are never more active after eating a lot of candy, or that bad parenting makes no difference. Rather, these are not adequate explanations for what causes ADHD.
Sudderth and Kandel make a point to discredit Social Construction theory, proposed by some who argue that ADHD is an “excuse” for lazy people and marks poor motivation and willingness to work. They cite one author who claims ADHD is a covert way to support special education and explain away educational deficits of minority children. They offer that this subtle “irrelevant racial slant” has little research to support it, and encourage that ADHD be taken seriously.
Several theories supported by research for what does cause ADHD include:
Catecholamine theory: Catecholamines are a subgroup of neurotransmitters that include Dopamine, Serotonin, and Norepinephrine. These chemicals carry messages from one neuron in your brain to another one. It is thought, and some studies clearly support, that when a person has ADHD, they have too little of a neurotransmitter called Dopamine. Drugs like Ritalin help your body reuse Dopamine, and thus may help mitigate the effects of the disorder. Other theorists point to a problem with too much of the neurotransmitter norepinephrine, which results in the brain being “keyed up,” as if a chemical messenger is constantly sending the brain the message to be ready for anything.
Frontal Lobe Functioning: There are many documented cases of an adult who suffered damage to the prefrontal cortex (the very, very front of your brain) and then began to show symptoms like those seen in ADHD clients. This theory holds that a difference in the prefrontal lobes from birth (rather than damage to the area suffered later) results in poorer planning skills, impaired processing of information, and the apparent inability to “think before you act” commonly seen in ADHD people. Anatomical differences, changes in the individual’s ability to use sugar to power neurons, and unusual blood flow to the brain have all been seen in ADHD clients.
For more information, see Biological Contributions to the Presentation and Understanding of Attention-Deficit/Hyperactivity Disorder: A Review 2001, by Bradley and Golden, published in Clinical Psychology Review, volume 21, issue 6, pages 907-929.
Myths about ADHD
There are many myths about ADHD and Ritalin including:
- Medication for ADHD stunts a child’s growth, results in aggressiveness, and increases risk to abuse drugs and alcohol in adolescence and adulthood
- Stimulants are the only medication for ADHD children, and the only effective treatment, but they lose their effectiveness when the child reaches puberty
- Using a child’s age, height, and weight, the doctor can find the exact dosage of medication a child needs
- Medication treats all aspects of ADHD, and stimulants are “miracle” drugs
- There are too many children medicated for ADHD
- Since the medication only effects the child’s ability to learn, there’s no need to give it during the summer or after school
- Trying Ritalin or another drug with a child is the best way to see if a child is ADHD
These myths are discussed below briefly, but Garber and colleagues, and Ingersoll all discuss these points in greater details:
- long term studies have not supported the stunted growth myth, as studies of adults who took Ritalin as children show no differences in height and weight. A short-term change might be noted, but over the course of three years, children treated with stimulants showed no differences compared to peers. Some of the side-effects are unpleasant or worrisome to parents (e.g., decreased appetite and sleep disruptions), but many of the side-effects of Ritalin and other stimulants are dose-related. Sometimes small decreases in the dose can decrease the side-effects tremendously without too much of a drop in the desired effects of the drug.
- irritability and impulsivity, which can lead to aggressiveness, are symptoms of the disorder itself, and so it is hard to blame the medication for this. Sometimes coming off the medication in the afternoons results in more hyperactivity than is seen without the medication. A small decrease in the morning dose, compensated for by a small afternoon dose, may resolve some of this. Further, experiencing chronic school difficulties and failures, having limited social skills and support, and feeling constantly nagged and supervised by adults can lead to resentment and rebellion that cause more problems that do not really stem from the medication.
- ADHD children, even on medication, remain more impulsive than most children, and if their medication is reduced or halted at puberty, their natural impulsivity and poor judgment may be more the reason for their experimentation with drugs than a history of Ritalin usage under a physician or psychiatrist’s monitoring. Likewise, an impulsive personality style can lead to some reckless or poorly thought out behaviors, leading to problems with authority figures, difficulties driving and attending to all the information a careful driver must notice.
- Some do advocate “drug holidays” over the weekends and summer, but others argue that this reduces ADHD to a “school disorder” and stimulants to “school drugs,” ignoring the social and self-esteem aspects of the disorder.
- Periodic re-evaluations of the medication are recommended. For example, in late winter and spring, when teachers and other adults know the child’s routines and personality well, the children can go off of the medication. If going without the medication for two weeks produces numerous and intolerable changes in behavior, mood, and functioning, then you know the medication is still needed.
- Medications, when given in the right dose, can produce changes in behavior within 20 to 30 minutes. However, determining the right dose for a child or adult is not based on weight, age, and height charts as with other drugs, and it takes some experimentation. Likewise, a person who does not respond to one stimulant may respond to another, and a child who is non-responsive at one age may be responsive in another year or two. Likewise, a parent or adult administering the medication can increase its effectiveness, as there are less likely to be “forgotten” doses.
- Insomnia is often a problematic side-effect, but giving medication earlier in the day, or decreasing it may help with this. Some parents complain of weight loss, and giving medication with meals, or making bedtime milkshakes with some dietary supplement can help overcome this.
Diagnosing the Problem
If you want to make sure that you are correctly diagnosing ADHD, or that your child is correctly diagnosed, here are several points to keep in mind:
- read about different medical, learning, and psychological problems that might mimic ADHD (e.g., drug and alcohol problems, steroid use, bipolar disorder, and anxiety disorders). Also, learn about ADHD. A professional that says children outgrow ADHD, thinks Ritalin is a “magic pill,” or who does not see the need for therapy for a child with ADHD is likely out of date and unable to treat ADHD with the most effective means.
- rule out medical problems and medication side-effects. Sometimes “inattentive” children have a vision or hearing problem, which explains their difficulties listening to instructions and reading homework assignments off the board. Likewise, medications for asthma often produce a sense of being “wired” and anxious that can impact a child’s behavior even more than that of adults.
- rule out emotional problems, such as anxiety, depression, and family stress, which can produce many of the same symptoms as ADHD. Many of the children seen in my practice have been referred by teachers due to behavior problems in the classroom, which are based not on neurological conditions like ADHD, but instead on extended emotional stresses at home, like impending divorce, financial stresses, or the anniversary of a death of a loved one.
- assess for learning disabilities, which can frustrate a child and make them appear to have some of the symptoms of ADHD, like impulsivity, inattentiveness, and poor motivation to learn. Psychologists are typically best suited to do this.
- follow the criteria for diagnosing the different types of ADHD (inattentive, hyperactive/impulsive, and mixed types) closely, and obtain data on behavior from multiple people in multiple settings to assure the diagnosis is accurate. Use of unstructured interviews as well as formal rating sheets is often helpful.
- formally test attention, concentration, decision-making, and learning processes, especially for children, as structured and well-researched and designed tests can often reveal what casual observation in the classroom can not.
- be prepared for the doctor patient interview, and openly discuss where you got information about ADHD and other disorders, why you think you or your child has it, what specific symptoms you show that you think indicate ADHD, and in what circumstances these symptoms are noticeable. Be willing to talk honestly about your feelings on taking medication for this, or trying other treatment approaches.