Table 1.

Symptomatology of attention-deficit/hyperactivity disorder and the corresponding areas of functional impairment

The symptoms
Inattention	• Failing to pay close attention to details and making careless mistakes at work or other activities • Difficulty sustaining attention • Seemingly ‘not listening’ when spoken to directly • Often failing to follow through on given instructions and finding it hard to finish chores or duties in the workplace • Having problems organizing tasks and activities • Being reluctant to engage in tasks that require sustained mental effort • Often losing things that are necessary for given tasks or activities • Being easily distracted by irrelevant stimuli or unrelated thoughts (‘wandering mind’) • Often being forgetful in daily activities
Hyperactivity and impulsivity	• Often fidgeting with or tapping hands or feet / squirming in one’s seat • Often leaving one’s seat in situations in which one is expected to remain seated • Often feeling restless (or agitated inside; finding it hard to relax) • Finding it hard to engage in leisure activities quietly • Often ‘being on the go’; acting as if ‘driven by a motor’ • Talking excessively • Often blurting out answers before a question has been completed • Often finding it difficult (frustrating) while awaiting one’s turn (e.g., waiting in line) • Often interrupting or intruding on others
The likely areas of impairment (with examples)
Health problems and psychiatric comorbidities	• Specific learning disorders and executive dysfunctions • Developmental coordination disorders • Speech and language disorders • Mood and anxiety disorders • Autism spectrum disorders • Obsessive–compulsive disorder • Tic disorder • Substance use disorders • Overweight, obesity and related metabolic disorders • Accidents (including driving safety issues) and related injuries • Suicidality
Other reasons for functional impairment	• Undermined sense of well-being (i.e., lower quality of life) • Emotional dysregulation:*    − Problems with temper control (i.e., pronounced irritability with frequent, yet short-lived, outbursts of anger)    − Emotional over-reactivity (i.e., noticeable problems with managing ‘everyday stressors’, leading to the pervasive sense of being overwhelmed)    − Mood lability (i.e., typically swinging from normal mood, to sadness, to mild excitement – and back again…)
Academic and occupational challenges	• Under-performing at school or at work • ‘Staying back’ (e.g., repeating classes), as a consequence of problems related to inattention • Special education needs • School expulsion / dropping out
Social/interpersonal problems	• Inadequate social skills • Long-term pattern of impaired family / intimate relationships

^* Reduced ability to modulate the current emotional state in a contextually adequate and goal-directed manner

Adapted from American Psychiatric Association (2013), Volkow and Swanson (2013), Shaw et al. (2014), Faraone et al. (2015), Moukhtarian et al. (2018), Kooij et al. (2019b) and Boedhoe et al. (2020)