ADHD represents a persistent pattern of developmentally inappropriate levels of inattention, hyperactivity, and/or impulsivity [10, 11]. Although estimates vary, research conducted in the last decade indicates that, on average, 55% of children and adolescents diagnosed with ADHD in childhood will continue to have the disorder in adulthood [888]. Attentional difficulties in particular are more likely to persist into adulthood, whilst impulsivity and hyperactivity tend to diminish over time [889]. Adult symptoms are expressed differently to the way in which they are expressed in childhood, and may include [10, 11]:
- Difficulties paying close attention to detail.
- Difficulties maintaining focus.
- Easily distracted.
- Difficulties completing tasks or projects.
- Disorganisation.
- Procrastination.
- Lack of motivation.
- Difficulties concentrating or studying (which may present as academic underachievement).
- Occupational or workplace difficulties.
- Forgetfulness, including the frequent loss of possessions.
- Restlessness.
- Difficulties with time management.
- Difficulties sleeping, and/or fatigue.
- Irritability, frustration, or anger.
- Problems forming and maintaining relationships.
- Difficulty obtaining and/or maintaining stable employment.
- History of imprisonment or frequent contact with police.
Some symptoms which clients may present with, such as problems sleeping, irritability and fatigue, are not unique to ADHD, but are common to many mental disorders.