Core Symptoms of ADHD

Anyone who knows me says I'm not like other people but they don't really see the side that I struggle with, the mood swings and not completing things. I can be quite impulsive and I think about things a bit differently to other people. I look at things in a different way I suppose. When my tablets wear off I can have mood swings. It's hard sometimes, but I don't really notice it so much. It's more when I've got a lot going on...I get stressed easily. I can't multitask or get things completed on time.

The symptoms of ADHD are inattention, hyperactivity and impulsivity leading young people to present as disorganised, chaotic, restless and emotionally labile. They struggle with these behaviours more than other children their age, and may have difficulty with these behaviours across different areas of their life; home, school, social or leisure activities. Children and young people vary in their symptom presentation, leading to different diagnostic classifications, for example girls more frequently present with inattentive symptoms rather than disruptive behaviours and are thus classified as 'ADD' (predominantly inattentive type) [1] (see Module 1). As children mature there is often a shift in the way symptoms are expressed with hyperactivity and impulsivity modifying more than attentional symptoms [2]. In adolescents hyperactivity is more subtle than the overactive or boisterous behaviours seen in young children, such as rolling around the floor or running about recklessly and without purpose. It is experienced more as feelings of inner restlessness and fidgeting. This may have contributed to the misconception that ADHD only affects young children.


There are several different domains, or aspects, of attention. These include (1) selective attention, which is the ability to focus down on one particular thing (e.g. proof reading for errors); (2) divided attention, which is the ability to focus on two or more things at the same time (e.g. driving a car and having a conversation); (3) shifting attention, which involves moving focus between two or more things (e.g. following instructions to assemble flat-pack furniture); and (4) sustained attention, which is being able to focus on something for any length of time (e.g. revising for exams or doing homework).

If my mind's not being challenged you just end up doing nothing. If I don't plan or set my day up I'll literally just be sitting in a chair watching naff telly for a whole 7 hours... what a waste.

In today's society the ability to multitask is central to achievement in daily life, at school, work and at home, and this requires individuals to have good attentional control and information processing skills. Young children may benefit from structured school settings and teacher-parent collaborations that aim to maximise achievement by optimising the environment (e.g. sitting at the front of the class, one-to-one tuition, mentoring, support). However, this often changes in the teenage years when youngsters strive for more autonomy. At the same time the school environment becomes more challenging as they are required to take greater responsibility for self-management and organisation. At school, for example, they have to cope with more complex timetables involving room and staff changes, organise homework and school projects and meet competing deadlines. They also start to organise their own social activities; and many balance part-time work with other responsibilities and chores at home.

Individuals with ADHD often report that they are more able to maintain their focus if an activity holds a particular interest for them. This can be confusing for parents and teachers who do not understand why the child cannot complete an English assignment and turn this in on time yet can sit for hours on Facebook or arrange a fashion show as an extra-curricula activity. This may be perceived as a lack of cooperation or in some cases rebellious behaviour.

The key is to identify adaptive strategies that the young person can set and apply themselves to maintain motivation for tedious tasks or tasks that do not hold their interest. These may include setting goals, breaking tasks down into smaller steps, the introduction of pre-determined breaks, and incorporating immediate and longer term reward systems to reward achievement.

Box 1: Symptoms of inattention [3]
  • Often fails to give close attention to detail: difficulty remembering where they put things. In work this may lead to costly errors. Tasks that require details are tedious (e.g. income tax returns) and become very stressful. This may include overly perfectionistic and rigid behaviour, needing too much time for tasks involving details in order to prevent forgetting any of them.
  • Often has difficulty sustaining attention: inability to complete tasks such as tidying room or mowing the lawn without forgetting the objective and starting something else. Inability to persist with boring jobs. Inability to sustain sufficient attention to read a book that is not of special interest, although there is no reading disorder. Inability to keep accounts, write letters or pay bills. Attention, however, can often be sustained during exciting, new or interesting activities (e.g. using the internet, chatting and computer games). This does not exclude the criterion when boring activities are not completed.
  • Often does not appear to listen when spoken to: adults receive complaints that they do not listen, and that it is difficult to gain their attention. Even where they appear to have heard, they forget what was said and follow through. These complaints reflect a sense that they are 'not always in the room', 'not all there' or 'not tuned in'.
  • Fails to follow through on instructions and complete tasks: adults may observe difficulty in following other people’s instructions. Inability to read or follow instructions in manual for appliances. Failure to keep commitments undertaken (e.g. work around the house).
  • Difficulty in organising tasks or activities: adults note recurrent errors (e.g. lateness, missed appointments or missing critical deadlines). Sometimes a deficit in this area is seen in the amount of delegation to others such as secretary at work or spouse at home.
  • Avoids or dislikes sustained mental effort: putting off tasks such as responding to letters, completing tax returns, organising old papers, paying bills or establishing a will. One can enquire about specifics then ask why particular tasks were not attended to. These adults often complain of procrastination.
  • Often loses things needed for tasks: misplacing purse, wallet, keys and assignments from work, where car is parked, tools and even children!
  • Easily distracted by extraneous stimuli: subjectively experience distractibility and describe ways in which they try to overcome this. This may include listening to white noise, multitasking, require absolute quiet or creating an emergency to achieve adequate states of arousal to complete tasks, many projects going on simultaneously and trouble with completion of tasks.
  • Forgetful in daily activities: may complain of memory problems. They head out to the supermarket with a list of things, but end up coming home having failed to complete their tasks or having purchased something else.


Younger children with ADHD typically present with greater behavioural disturbance and hyperactivity, for example they might race about the house, run across roads without looking, answer back or talk over others, not wait their turn, and get upset quickly over seemingly small things. They may find it difficult to sit still for long periods (e.g. at the dinner table, or in lessons or assembly at school).

As children grow up some impulsive behaviours and hyperactivity may diminish or become more purposeful (e.g. directed in sporting activities). Most commonly adolescents and adults describe feeling an inner restlessness and need to fidget, as opposed to the urge to run around aimlessly. Many also describe ceaseless mental activity, saying that their minds are always 'on the go'.

Box 2: Symptoms of hyperactivity [3]
  • Fidgets with hands or feet: this item may be observed, but it is also useful to ask about this. Fidgeting may include picking their fingers, shaking their knees, tapping their hands or feet and changing position. Fidgeting is most likely observed while waiting in the waiting area of the clinic.
  • Leaves seat in situations in which remaining seated is usual: adults may be restless. For example, they experience frustration with dinners out in restaurants and are unable to sit during conversations, meetings and conferences. This may also manifest as a strong internal feeling of restlessness when waiting.
  • Wanders or runs about excessively or frequently experience subjective feelings of restlessness: adults may describe their subjective sense of always needing to be 'on the go', or feeling more comfortable with stimulating activities (e.g. skiing) than with more sedentary types of recreation. They may pace during the [assessment] interview.
  • Difficulty engaging in leisure activities quietly: adults may describe an unwillingness/dislike to ever just stay home or engage in quiet activities. They may complain that they are workaholics, in which case detailed examples should be given.
  • Often 'on the go' or acts as if driven by a motor: significant others may have a sense of the exhausting and frenetic pace of these adults. ADHD adults will often appear to expect the same frenetic pace of others. Holidays may be described as draining since there is no opportunity for rest.
  • Talks excessively: excessive talking makes dialogue difficult. This may interfere with a spouse's sense of 'being heard' or achieving intimacy. This chatter may be experienced as nagging and may interfere with normal social interactions. Clowning, repartee or other means of dominating conversations may mask an inability to engage in give-and-take conversation.


Impulsivity can be classified as behavioural or cognitive, with individuals typically experiencing a combination of both. A difficulty with self-monitoring their own behaviour, or poor self-regulation, is a hallmark of ADHD that for many persists into adulthood.

Behavioural Impulsivity

Behavioural impulsivity is observed in actions. A behaviourally impulsive person responds prematurely to situations; they act spontaneously without thinking. This may lead them to lash out at others verbally or physically; they may blurt out hurtful comments without being able to stop themselves, they may start fighting or damage property. They may put themselves at risk by engaging in reckless or dangerous behaviours such as driving at high speeds, promiscuity and unprotected sex.

Big paragraphs are so daunting, I don’t even like to tackle big paragraphs. They scare me, because I know when I get one sentence in, I won't even know what I've read. If I can't finish an exam properly, which affects my grades although I'm working as hard as I can, how the hell am I going to pass my university tests? And that scares me...I struggle to concentrate and listen to someone. How the hell am I supposed to learn while writing and listening? I don't know what I'm going to do, this is probably the first time I've talked about it. I am so scared. I really am.

By definition, impulsive behaviours occur without planning or malice, and without consideration of consequences. Nevertheless, this is commonly unacceptable to family, friends or school teachers for many reasons. It causes hurt and distress to people they care about, leads to conflict and confrontation in interpersonal relationships, and the behaviour may even put themselves and others at risk of harm.

Cognitive Impulsivity

Cognitive impulsivity is defined as only seeing the immediate short-term gain of an action. The tendency to jump to conclusions is debilitating because this is associated with 'errors' in thinking and erroneous assumptions. This usually results in poor decisionmaking as the person does the first thing that springs to mind which may not be the best.

Young people need to learn to engage in a functional process involving the generation and consideration of different potential solutions to a problem, weighing up the advantages and disadvantages of each solution, and applying a consequential thinking process. If a person learns to stop and think and generate several potential solutions to a problem, they give themselves 'choice' in the form of multiple options. If the first does not succeed, then they have others to try.

Impulsive symptoms may lead to negative consequences in adolescence. The persistence of hyperactivity/impulsivity can result in a pathway into inappropriate and/or reckless behaviours that often involve rule-breaking, substance use, and antisocial behaviour. Thus it is important to find effective ways to manage these symptoms.

Box 3: Symptoms of impulsivity [3]
  • Blurts out answers before questions have been completed: this will usually be observed during the [assessment] interview. This may also be experienced by probands as a subjective sense of other people talking too slowly and of finding it difficult to wait for them to finish. Tendency to say what comes to mind without considering timing or appropriateness.
  • Difficulty waiting in turn: adults find it difficult to wait for others to finish tasks at their own pace, such as children. They may feel irritated waiting in line at bank machines or in a restaurant. They may be aware of their own intense efforts to force themselves to wait. Some adults compensate by carrying something to do at all times.
  • Interrupts or intrudes on others: most often experienced by adults as social ineptness at social gatherings or even with close friends. An example might be an inability to watch others struggle with a task (e.g. opening a door with a key) without jumping in to try for themselves.

Emotional Lability

I think I'm probably more prone to feeling down....Even in a day I'll swing from being really happy and then the next minute being really, really down.

Many ADHD experts view mood instability, or emotional lability, to be the fourth 'symptom' of ADHD. This differs from anxiety, depression or bipolar disorders which are episodic in nature. In adult clinics emotional over-reactivity and temper outbursts are commonly a presenting complaint that responds to stimulant medication along with the 'core' ADHD symptoms [3].

In adolescence, teenagers may be especially volatile as, aside from puberty, they are developing their personal and social identity. They are vulnerable at this time for developing mood and anxiety disorders and, for those with unrecognised ADHD, the presence of these symptoms may mask the underlying ADHD syndrome. When conducting an assessment therefore it is important to be mindful that ADHD symptoms start early in life; they are persistent and non-episodic. They are more trait-like than symptom-like since there is no clear change from a premorbid state.

Negative Functioning

For a diagnosis of ADHD, the presenting individual must experience symptoms that negatively impact on their functioning in two or more settings (i.e. social, academic or occupational activities). Thus the symptoms must be pervasive and present in multiple domains.

Practitioners must bear in mind that achievement and/or function is relative to potential. Some people may appear to function quite well, for example, by obtaining mid-range GCSE qualifications, leaving school and finding unskilled employment. However this may be disproportionate to a high IQ and family expectations, with siblings attending university and gaining professional occupations.

Some young people, especially those with high IQ's, may cope by applying strategies (e.g. making lists) that limit functional impairments. These may work in some circumstances but not others such as social settings. Others apply dysfunctional strategies, e.g. alcohol and substance misuse. Asherson (2005) [3] has provided guidance for assessment of impairment in young people and adults (see Box 4).

Box 4: Assessment of impairment [2]

Impairment is a requirement for a diagnosis of ADHD. The clinician needs to assess whether an individual is impaired relative to his or her own potential, or relative to expected norms. Some very bright individuals are not impaired relative to expected norms, but reveal unequivocal impairment relative to their own potential. It is important to enquire into different areas of life since someone with ADHD may be brilliant at some sorts of work while feeling totally inadequate because of their inability to be organised or to do work around the house.

  • Quality of life: mood lability, a short fuse and constant efforts to correct scatterbrained mistakes are frustrating and demoralising.
  • Family life: even where an adult with ADHD feels fine, interviewing the patient's spouse/family may reveal significant dysfunction.
  • Work: while some ADHD individuals find work that is compatible with their symptoms, they may be impaired by not being able to move in new directions in which they would otherwise have desired to move. Others may be functioning in attention-demanding professions, but at great emotional cost and without much success. Work may not be commensurate with their intelligence and educational background. This is usually experienced as underachievement.
  • Love: ADHD is hard on relationships and some adults with ADHD give up on their capacity for intimacy and lead an isolated existence. They may be unaware of the ways in which their ADHDcaused behaviour patterns have contributed to relationship failures.
  • Education: many adults with ADHD are impeded from obtaining an education appropriate to their potential (usually assessed by IQ). A history of academic underachievement or erratic performance represents academic impairment.
  • Activities of daily life (ADL): even a high-functioning individual with ADHD may have difficulties with ADL, such as shopping, cleaning, dressing or managing money. The deficit is not observed in what the individual can do, but in what they actually do, so direct observation or an informant is required to assess this correctly.

Symptom Remission

For some, core symptoms may start to decline during the adolescent years. This is not a uniform remission but a heterogeneous progression with some individuals experiencing full remission by adulthood, some partial remission and others none at all [4,5]. In adolescence and early adulthood, symptoms of inattention typically persist to a greater degree than hyperactivity or impulsivity (see Figure 1), and around 65% of ADHD children will experience some persisting symptoms as young adults that will be associated with significant impairment [4].

Age-related changes have been investigated in a cross-sectional study of a clinical sample diagnosed with ADHD and divided into four groups based on decade of life and matched for childhood ADHD severity [6]. Symptoms improved according to objective measures (informant ratings and neuropsychological assessment), however inattentive symptoms increased with age according to self-ratings. Thus the subjective experience of people with ADHD was that their symptoms worsen as they become older, and it was found that this may be associated with an increase in symptoms of depression. The study highlights the importance of affective symptoms in older persons with ADHD and the potential for misdiagnosis.


Gender Differences

In the general population, more boys than girls have ADHD with a ratio of approximately 4:1 in children [7]. However the gender difference becomes far less skewed with age as more adult females are identified and diagnosed [8]. This may be explained by females having fewer externalizing problems, hyperactivity, aggression and conduct problems than boys. They suffer more from internalizing problems and inattention, and thus are less likely to present with overt behavioural problems and to be referred for treatment. With maturity a change in referral pattern may also influence the gender ratio within clinical populations as more adult women seek help from psychiatrists than men (most commonly for mood and anxiety disorders).

Key Points from Module 2

Box 5: Key points from Module 2 – Symptoms of ADHD
  • ADHD symptoms of inattention, impulsivity and hyperactivity affect young people who may present as disorganised, chaotic, reckless and emotionally labile.
  • One difficulty with assessing ADHD in young adults is that the symptom classification was developed with children in mind which may not correspond well with older age-groups.
  • In the adolescent years, teenagers may be especially volatile in mood as, aside from puberty, this is a time when they are developing their personal and social identity.
  • For a diagnosis of ADHD, symptoms must cause negative functioning in two or more settings (e.g. home, school, work). Impairment should be considered relative to potential.
  • Around two-thirds of ADHD children will continue to experience significant impairment as young adults.
  • In adolescence symptoms of inattention typically persist to a greater degree than hyperactivity and impulsivity.
  • A gradual pattern of decline in symptoms is seen as individual’s move into middle adulthood. Subjectively however symptoms of inattention may be perceived to become worse and this may be due to comorbid mood disorders.


[1] Biederman, J., Mick, E., Faraone, S,V., Braaten, E., Doyle, A., Spencer, T., Wilens, T.E., Frazier, E., & Johnson, M.A. (2012). Influence of gender on Attention Deficit Hyperactivity Disorder in children referred to a psychiatric clinic. The American Journal of Psychiatry, 159(1), 36-42.

[2] Marsh, P.J., & Williams, L.M. (2004). An investigation of individual typologies of attention-deficit hyperactivity disorder using cluster analysis of DSM–IV criteria. Personality and Individual Differences, 36(5), 1187-1195.

[3] Asherson, P. (2005). Clinical assessment and treatment of attention deficit hyperactivity disorder in adults. Expert Review of Neurotherapeutics, 5(4), 525-539.

[4] Faraone, S., Biederman, J., & Mick, E. (2006). The age-dependent decline of attention deficit hyperactivity disorder:A meta-analysis of follow-up studies. Psychological Medicine, 36(2), 159-165.

[5] Young, S., & Gudjonsson, G. (2008). Growing out of Attention-Deficit/Hyperactivity Disorder:the relationship between functioning and symptoms. Journal of Attention Disorders, 12(2), 162-169.

[6] Bramham, J., Murphy, D., Xenitidis, K., Asherson, P., Hopkin, G., & Young, S. (2012). Adults with ADHD; An investigation of age-related differences in behavioural symptoms, neuropsychological function and comorbidity. Psychological Medicine, 42, 2225-2234.

[7] Ford, T., Goodman, R., & Meltzer, H. (2003). The British Child and Adolescent Mental Health Survey 1999: the prevalence of DSM-IV disorders. Journal of the American Academy of Child and Adolescent Psychiatry, 42(10), 1203-1211.

[8] Kessler, R.C., Adler, L., Berkley, R., Biederman, J., Conners, C.K., Demler, O. ... Zaslavsky, A.M. (2006). The prevalence and correlates of adult ADHD in the United States: Results from the National Comorbidity Survey Replication. American Journal of Psychiatry, 163(4), 716-723.

Further Reading and Useful Resources

National Institute for Clinical Excellence. (2009). Attention deficit hyperactivity disorder: Diagnosis and management of ADHD in children, young people and adults. NICE clinical guideline 72. London.

Young, S., Murphy, C.M., & Coghill, D.(2011). Avoiding the 'twilight zone': Guidance and recommendations on ADHD and the transition between child and adult services. BMC Psychiatry. 11:174, dx.doi. org/10.1186/1471-244X-11-174

Young, S., & Bramham, J. (2012). Cognitive Behavioural Therapy for ADHD Adolescents and Adults: A Psychological Guide to Practice, Second Edition. Chichester: John Wiley & Sons.

Young, S. (2013). The 'RAPID' cognitive behavioral therapy program for inattentive children: preliminary findings. Journal of Attention Disorders, 17(6), 519-526.

Young, S., Fitzgerald, M., & Postma, M.J. (2013). ADHD: making the invisible visible An Expert White Paper on attention-deficit hyperactivity disorder (ADHD): policy solutions to address the societal impact, costs and long term outcomes, in support of affected individuals,