- What is Attention Deficit Hyperactivity Disorder in Adults (Adult ADHD)?
- Risk Factors
- Clinical Examination
- How is it Diagnosed
What is Attention Deficit Hyperactivity Disorder in Adults (Adult ADHD)?
Attention deficit hyperactivity disorder (ADHD) is a behavioural syndrome underpinned by differences in an individual’s brain shape and function, and characterised by hyperactivity, impulsivity and/or inattention. While these symptoms are experienced by all people from time to time, they are severe and persistent in those with ADHD, and therefore interfere with these individuals’ normal functioning.
Individuals who suffer from ADHD often have difficulty functioning in social, academic and occupational environments. They may struggle to follow directions, remember information, concentrate, organise tasks or complete work within time limits.
Although best known as a condition of children in preschool and early school years, the presence of ADHD is increasingly recognised in some adults as a remnant of their childhood conditions. Adult ADHD was first observed in 1976, and first recognised as a condition distinct from the childhood disorder, in 1987.
Between 30% and 70% of children with ADHD will continue to display symptoms of the disorder in adulthood. Conservative estimates of ADHD prevalence in adults suggest that nearly 1 in 20 adults in the general population have ADHD. However, other evidence suggests prevalence is actually much higher than this.
A large survey of households in the United States estimated the prevalence of ADHD to be 4.4% of adults aged 18–44. Based on Australian population figures, it is estimated that over 360,000 Australians between the ages of 18 and 44 have ADHD.
In 2003, less than 0.1% of the adult population (7 in 10,000 adults) were prescribed stimulant medication for ADHD, compared to an estimated 4.4% who exhibited ADHD symptoms. This suggests that many adults who exhibit symptoms of ADHD are not diagnosed or treated for the condition.
It is interesting to note that ADHD is equally prevalent in men and women later in life, whereas in children, 4 out of every 5 diagnosis are made in boys. As there is no evidence to suggest that boys are less likely than girls to carry their condition into adulthood, the different proportions of males and females who have ADHD in adulthood may reflect under-diagnosis of ADHD in girls.
It is also interesting that for every adult female on stimulant medication, there are 1.7 adult males on stimulants. As ADHD is equally prevalent in adult men and women, this shows the condition is undertreated in women.
For more information on ADHD in children, see Childhood ADHD.
ADHD is a persistent condition which arises in early childhood and continues into adulthood. Adults who were diagnosed with or experienced the symptoms of ADHD as children are more likely to have ADHD as adults. It is important to note, however, that an adult cannot develop ADHD; the condition is always present from childhood.
It has been found that a number of genes for the substances that transport messages from the brain do not work properly in individuals with ADHD, and these genes are inherited. Importantly, this genetic influence is believed to be more strongly associated in cases where ADHD persists to adulthood, as compared to individuals for whom symptoms subside after childhood.
Family studies show that 10–35% of immediate family members of children with ADHD are likely to have the disorder, and the risk to siblings is 35%. Identical twins are more likely to both be affected than non-identical twins.
That said, not all individuals with the genetic predisposition to ADHD will develop the disorder. Environmental factors also influence who does and does not develop ADHD.
Environmental and family factors
Exposure during pregnancy with cigarettes, alcohol and other substances (e.g. cocaine) may increase the risk of ADHD. Maternal stress during pregnancy also increases the risk of ADHD in children. Preschool children with higher levels of lead in their bodies are also at higher risk of developing ADHD.
Chaotic parenting may increase the risk of developing ADHD, but the relationship between ADHD and parenting may result from both negative aspects of the child influencing the parents’ behaviour, and of the parents influencing the child’s behaviour.The children of parents who are more demanding, aversive, negative, controlling, intrusive, disapproving, power assertive and less rewarding are at greater risk of ADHD.
Acquired brain injury and childhood illness can also increase the risk of ADHD.
Children from lower socioeconomic classes have higher rates of ADHD, and are more likely to be undertreated for their disorder. The increased rates of ADHD in poorer children is thought to relate to greater exposure to factors which increase the risk of ADHD (e.g. tobacco exposure during pregnancy, childhood lead exposure, complications of pregnancy and delivery). In addition, the negative impact of ADHD on social, academic and career outcomes may cause ADHD sufferers to cluster in lower socioeconomic groups.
Studies have shown a possible link between the use of cigarettes and alcohol during pregnancy, and the risk of ADHD in offspring. Maternal substance abuse (e.g. cocaine, nicotine) may also cause ADHD-like symptoms.
Brain structure factors
Some studies suggest that ADHD is caused by a compromised structure in areas of the brain that relate to inhibition and attention. There is also evidence that the size of parts of the brain in children with ADHD is slightly smaller than in children without ADHD.
ADHD symptoms may be a result of cognitive deregulation, where the child’s behaviour results from insufficient forethought, planning and control, and leads to impulsive responses and higher error rates.
Children with ADHD may also respond more impulsively in order to complete tasks more quickly, and therefore avoid delays.
In a situation where the child is not in control (e.g. in a classroom where they are expected to behave in a certain way), the child could achieve control by either daydreaming (inattention) or by fidgeting (hyperactivity).
ADHD has been linked to the intake of food additives, food colourings and refined sugar. These substances have been shown to exacerbate ADHD symptoms.
Diets that exclude foods containing substances which worsen behavioural problems, such as the Australian-developed FAILSAFE diet, have been used as treatments for ADHD since the 1980s.
While the association between diet and ADHD symptoms is clear, dietary interventions alone are not enough to treat the symptoms of ADHD, and are best used in combination with pharmacological and educational interventions.
Children with iron deficiency have more severe symptoms of ADHD than those without iron deficiency.
There is no evidence to suggest ADHD can develop during adulthood. Those who have ADHD later in life would have been experiencing persisting symptoms since they were a child. Some adults may grow up with ADHD that was diagnosed in childhood while others remain unaware that they have the disorder
Core behavioural symptoms of ADHD
The behavioural symptoms of ADHD can be classified by three core symptoms: inattention, hyperactivity and impulsivity. Many adults may not recognise these symptoms as ADHD symptoms. Rather, they may just think that their mind is wandering, they are always on the go, or they jump to decisions too quickly.
Adult ADHD and inattention
Inattention is a symptom which individuals eventually diagnosed with ADHD do not usually report to their doctors. Many adults have already developed strategies to reduce or overcome the resultant impairment in their daily functioning. Adults with ADHD are no longer in school, so many avoid situations which require sustained attention, to avoid inducing stress. Inattention may be perceived by the individual’s friends, employer or family to be neglectful behaviour, poor time management, poor concentration, or difficulties with motivation and arousal (difficulty starting, completing, or switching tasks).
Adult ADHD and hyperactivity
Hyperactivity presents differently in adults as opposed to children. Symptoms of hyperactivity without inattention symptoms are less common in adults. In children hyperactivity may be seen as excessive running and climbing but in adults it is more likely to result in excessive or rapid thoughts, or a constant or chronic restlessness or agitation. Many adults transform this into purposeful behaviour, such as being constantly busy, talking excessively, choosing an active job, working two jobs, or working long hours. Constant movements (e.g. leg twitching, picking at hair and the inside of their mouth, teeth grinding) are also symptoms of chronic restlessness or hyperactivity in ADHD adults.
Adult ADHD and impulsivity
Impulsivity can present not only in behaviour (e.g. difficulty waiting turn, low frustration tolerance, impatience), but also in thinking and emotional reactions. Impulsive thinking may present as making decisions without all the required information, jumping to conclusions, and acting without thinking of the consequences. Impulsivity may also mean that an individual has difficulty controlling their emotions. Such behaviours can present as poor problem solving, speeding whilst driving, impulsively spending money, and interrupting conversations. They can cause difficulty in interpersonal relationships, in the workplace and in the criminal justice system.
Other behavioural symptoms which are associated with ADHD
Adult ADHD and feeling overwhelmed
Adults with ADHD often feel overwhelmed by demands, tasks that involve working memory, general life pressures, relationship problems (both interpersonal and intimate), difficulties with stress management, or feeling that “things just aren’t right”.
It is common for adults with ADHD to lack focus and attention, be restless or stressed and/or emotionally sensitive. They may also have difficulty setting goals and achieving them, be disorganised, and experience constant turmoil or patterns of crisis in their daily functioning.
Adult ADHD and poor working memory
ADHD can cause difficulties with working memory, and this results in individuals forgetting instructions; having difficulty recalling information that was just read; forgetting or being late to appointments, meetings or social plans; and losing or misplacing items (e.g. wallet, keys, etc).
Adult ADHD and social relationships
An adult with ADHD may have difficulties in their social relationships, and is unlikely to recognise the underlying cause of these difficulties. They may talk excessively, interrupt conversations or be impulsive and this can cause frustration and annoyance amongst their friends, family members and workmates.
Adult ADHD, sleep problems and arousal
It is now recognised that individuals with ADHD may have chronic difficulties with sleep, particularly getting to sleep, feeling lethargic when they wake up, and maintaining alertness during the day despite adequate hours of sleep. Feeling lethargic in the morning and late afternoon is common, as is a tendency to consume stimulants (e.g. nicotine, caffeine, sugar) to combat the lethargy.
Adult ADHD and mood regulation
Adults with ADHD are likely to have difficulty regulating their mood. The may report rapid mood changes, for example changing quickly from being in a low mood to being very excited. Mood changes can occur with or without environmental stimuli (e.g. seeing something exciting).
Adults with ADHD have often been in trouble with the criminal justice system, are likely to report substance use disorders, and have significant difficulty in interpersonal relationships and personal finances. At times, rapid speech, irritability, agitation, and flightiness of thoughts and behaviours may be apparent.
Feelings of dysphoria in adult ADHD often appear as discontent or boredom, rather than depression. However, depression is also commonly experienced by ADHD sufferers.
Adult ADHD and anger management
Adults with ADHD often also have difficulty controlling anger. Anger outbursts are often excessive and explosive, but individuals usually calm down quite quickly between outbursts. Some individuals may ‘hyperfocus’ on their anger and have difficulty ‘letting go’. Some individuals with ADHD are thus chronically irritable, frightened when they lose control, and have difficulty understanding and making assessments of their outbursts.
Adult ADHD and anxiety
Agitation and restlessness, which are common with adult ADHD, may lead to an anxiety disorder. In addition, trying to keep track of thoughts and having difficulty managing and organising daily routines also increases feelings of anxiety and panic. Research shows that many adults with ADHD also experience anxiety disorders.
Adult ADHD and substance abuse
There is a particularly high incidence of substance use disorders in adults with ADHD. Adults with ADHD who use substances are more likely to develop a substance use disorder, than adults without ADHD.
Adult ADHD and problem gambling
Research shows that up to 1 in 3 problem gamblers meet criteria for ADHD. It suggests that a neurological dysfunction which causes impulsivity and difficulty sustaining attention, also assists in the development of problem gambling. Individuals with both ADHD and problem gambling are likely to have significantly more difficulty controlling gambling urges, due to high impulsivity. In addition, gambling provides immediate reward and reinforcement, which acts as a relief or escape from perceived negative mood states (e.g. chronic boredom, low self-esteem, low mood, anxiety).
This information will be collected for educational purposes, however it will remain anonymous.
If a doctor suspects an individual has ADHD, they will ask them to undergo a physical examination and psychological tests. This will allow the doctor to determine whether or not the individual has ADHD or if they have another condition with similar symptoms to ADHD. Other health conditions that can mimic the symptoms of ADHD include, but are not limited to:
- Past acquired brain injury (e.g. serious head injury);
- Sleep disorders;
- Hormone disorders (e.g. hypothyroidism, hyperthyroidism).
Health problems which might arise as a result of ADHD include:
- Substance abuse;
- Poor nutrition;
- Fractures; and
- Poor sleep hygiene (that is behavioural and environmental factors which may interfere with sleep).
How is it Diagnosed
Diagnosing ADHD in an adult can be difficult, because people will typically not recognise the symptoms of ADHD and report them to a doctor. Most will simply feel unable to function in a way that allows them to accomplish in everyday life. Because the symptoms of ADHD are often also common in other disorders, an ADHD diagnosis must be made by a specialist with expertise in attention deficit.
The diagnosis of ADHD in adults is based on similar criteria to childhood ADHD. Diagnosis usually begins with an assessment of symptoms the patient has experienced in the past six months. This assessment is typically carried out using a questionnaire, which categorises symptoms as those of inattention or hyper-activity/impulsivity. These criteria allow for diagnoses of three different types of ADHD, that is:
- ADHD characterised predominately by inattention;
- ADHD characterised predominately by hyperactivity/impulsivity (relatively rare in adults);
- ADHD with combined inattention and hyperactivity symptoms.
A doctor who suspects a person to have ADHD is likely to ask them to complete a questionnaire, on which they rate how often they have experienced various symptoms of ADHD, using rating scale: 0- never or not at all; 1- sometimes or somewhat; 2- often or pretty much; 3- very often or very much. The symptoms are:
- Not paying close attention and making careless mistakes;
- Finding it difficult to pay attention;
- Finding it difficult to following verbal instructions;
- Not finishing tasks;
- Avoiding doing things that require a lot of concentration;
- Misplacing things;
- Being easily distracted;
- Being forgetful.
- Finding it difficult to sitting still;
- Being restless and jittery;
- Having trouble doing things quietly;
- Being always “on the go”;
- Talking too much;
- Acting before thinking things through;
- Getting frustrated when having to wait;
In order for a diagnosis of ADHD-inattentive or hyperactive to be made, the individual must have rated the frequency of at least 6 (3 for patients over 50 years) of the inattention or hyperactivity symptoms as occurring “often” or “very often”, in the past 6 months. In order for diagnosis of ADHD with both inattention and hyperactivity to be made, the person must rate at least 6 items on both of the scales as occurring “often” or “very often”.
A friend or relative who is aware of the behavioural patterns of individuals with suspected ADHD (e.g. someone that they live with or spend considerable time with), often also completes the questionnaire.
A doctor will also ask the individual about their history of symptoms during childhood. It may be necessary to obtain information from sources other than the patient, including school reports cardsand interviews the person’s parents, or other relatives or long term friends who may have witnessed the person’s behaviour as a child. At least some symptoms of ADHD must have been experienced during childhood for the condition to be diagnosed in an adult.
It is then necessary for the doctor to assess the degree to which ADHD impairs the individual’s functioning, which arise from ADHD symptoms in various settings such as the individual’s work, home and social life. Adult ADHD symptoms may be most apparent at work, as opposed to at school for children. However, as for diagnosis of the condition in childhood, functional impairment must occur in at least two different environments, and impair functioning to a significant degree, for a diagnosis of ADHD to be made. The symptoms must also occur independently of the symptoms of other developmental (e.g. schizophrenia) and mood (e.g. anxiety disorder) disorders.
The doctor will then ask the person about their developmental history, including their mother’s pregnancy, their childhood and educational history.
Questions about the mother’s pregnancy are likely to include:
- Maternal substance use;
- Pregnancy complications including diabetes and pre-eclampsia;
- Complications of childbirth including cord around the neck, breech delivery and lack of oxygen.
The doctor will also probably ask about the following aspects of the person’s childhood:
- Serious trauma, requiring hospitalisation;
- Verbal, physical and emotional abuse;
- Exposure to violence or other serious emotional trauma;
- Loss of consciousness.
With regard to the person’s education, the doctor might ask about:
- Academic achievement including grades throughout primary and secondary school, consistency of achievement, teachers’ comments, repeating a grade, dropping out and tertiary education;
- Disciplinary misconduct including suspension or expulsion;
- History of learning disability, special difficulty with reading, writing or maths, or learning assistance.
The person and their family’s psychiatric history is also likely to be investigated including:
- Substance abuse;
- Learning disability;
- Behavioural problems;
- Suicidal or self-harming behaviour.
30–70% of children with ADHD will continue to have troublesome symptoms of inattention or impulsivity as adults. Adult and childhood ADHD demonstrate similar responses to treatment and evidence shows that more than 50% of adults resolve ADHD symptoms by taking stimulant medication.
Studies have indicated that people diagnosed with ADHD tend to achieve poorer results in school, are less likely to graduate from high school or university and are less likely to continue postgraduate study. Accordingly ADHD is associated with lower employment rates and lower income for the individual.
A combined approach to the treatment of ADHD is recommended. Combined approaches involve medication intervention and well as psychosocial.
Psychosocial management may include:
- Psychotherapy for other psychiatric disorders, for example depression;
- Attending support groups;
- Drug and alcohol counseling;
- Behaviour management programs (e.g. day planning, developing meal routines); and
- Education for individuals, partners and family members about ADHD and its effects on behaviour, self-esteem, social skills, learning and functioning within the family.
Although psychosocial interventions can help individuals cope with the symptoms of ADHD, they cannot cure them. Treatment with medication is the mainstay of ADHD and generally involves treatment with stimulant medication. Stimulant medication is not addictive in adults with no other substance abuse disorders. Amongst individuals who abuse substances, there is evidence that stimulant therapy can reduce additional substance abuse. However doctors will prescribe stimulants for these individuals with caution, as they may interact with other drugs.
The side effects of stimulant medication can be quite severe in some individuals, but they usually reduce in the first three months of treatment. Individuals who are treated with stimulant medications will be asked to return to the doctor for regular check ups throughout this period.
Individuals who cannot take stimulants may be treated with anti-depressant medication.
Research has shown that using both medication and psychosocial strategies together is more effective in treating ADHD than either strategy used alone. The doctor will develop an individual treatment plan for each individual diagnosed with the condition.
New and emerging therapies
Future goals of ADHD research include developing treatments that are more specifically catered for the individual. This means that people who will respond poorly to a specific therapy will be identified early and this treatment can therefore be avoided and a better option explored. This will help decrease the symptom severity as well as decreasing the side effects of the medication. The extensive genetic research that is currently underway into ADHD will help this to become a possibility.
Organisations which offer assistance
The Learning and Attentional Disorders Society of WA (LADS) is a support, information and advocacy agency for people with ADHD and associated conditions. The Mission of LADS is to provide support, advocacy and accurate information to individuals, parents, families and all people affected by ADHD and associated conditions. For more information on this group, see LADS.
ADDults with ADHD (NSW) Inc. is the only registered charity in Australia that supports adults with ADHD, their partners and families. ADDults with ADHD is largely managed and advised by a team of psychologists and psychiatrists. They regularly update a referral register of experts in adult ADHD that health professionals may access. ADDults with ADHD support health professionals by aligning their organisation with evidence-based practice based on clinical research. For more information on this group, see ADDults with ADHD.
|For more information on the symptoms of ADHD and its medications, and some useful tools and animations, see Adult ADHD.|
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