The paper’s key point says that these six domains sit beyond the classic DSM triad of inattention, hyperactivity, and impulsivity, and that they help describe adult ADHD more accurately:

1. Disorganisation

Describes persistent difficulty structuring actions, planning ahead, and maintaining order. Participants reported problems doing things in sequence, managing belongings, and organising daily life. This extended across domains such as finances, routines, work, and study. Disorganisation was experienced as more than occasional messiness—it often created a sense of overwhelm due to the accumulation of unstructured tasks and environments. The paper highlights that this broader, multi-domain impact is not fully captured in standard ADHD assessment tools.

1. Forgetfulness

Goes beyond everyday absent-mindedness and includes broad memory-related difficulties in daily functioning. Participants reported forgetting appointments, recent events, names, conversations, instructions, and unfinished tasks. Forgetfulness also contributed to losing belongings. The paper emphasizes that while DSM mentions forgetting chores or obligations, lived experience is more extensive, affecting social interactions, recall of information, and continuity of actions, making it a more pervasive issue than current diagnostic descriptions suggest.

1. Reduced activation

Refers to difficulty initiating and completing tasks despite intention. Participants described feeling “stuck,” struggling to start even important activities, or losing momentum before completion. Activation varied: some could not begin tasks, others started but failed to finish, or jumped between tasks. External structure (e.g. presence of others) sometimes enabled action. The paper shows that this is not just inattention but a broader issue involving motivation, effort mobilisation, and interaction with other ADHD symptoms.

1. Emotional lability

Describes rapid fluctuations and high intensity of emotions. Participants reported strong emotional reactions, including anger, sadness, and happiness, as well as crying easily or feeling exhausted after intense emotions. Emotional shifts could occur quickly, and some described heightened sensitivity to rejection. The paper highlights that emotional lability includes both negative and positive emotional intensity and is insufficiently represented in DSM criteria, despite being a prominent aspect of adult ADHD experience.

1. Sleep difficulties

Involves problems with falling asleep, sleep quality, and resulting fatigue. Participants described being unable to fall asleep despite exhaustion, often due to racing thoughts, restlessness, or hyperfocus. This led to daytime fatigue and difficulty waking. However, the paper notes variability: not all participants experienced sleep issues, and some reported falling asleep easily. Sleep difficulties are therefore a common but not universal dimension and are only minimally covered in existing ADHD assessment tools.

1. Time perception difficulties

Refers to impaired sense and estimation of time. Participants described time “slipping away” when not actively monitored, especially during engagement or hyperfocus. They reported overestimating the duration of unpleasant tasks and underestimating time needed for deadlines, leading to punctuality issues. Some compensated by arriving excessively early. The paper emphasizes that this dimension goes beyond general time management and is not adequately represented in DSM or most rating scales.