Disease | Shared features | Differences |
Oppositional defiant disorder (ODD) | Resisting work or school tasks | Due to negativity, hostility and defiance (ODD) Due to difficulty in sustaining mental effort, forgetting instruction and impulsivity (ADHD) |
Intermittent explosive disorder (IED) | High level of impulsive behaviour | Serious aggression towards others; no attention problems (IED) Less aggression; prominent attention problems (ADHD) |
Autism Spectrum Disorder (ASD) | Dysfunctional motor behaviours | Fixed and repetitive stereotypic movements (ASD) Fidgetiness and restlessness (ADHD) |
Specific learning disorder (LD) | Learning problems | Not impaired outside of academic work (LD) Due to inattention due to frustration or lack of interest (ADHD) |
Intellectual disability (ID) | Inappropriate and low intellectual ability in academic setting | In all other life activities (ID) Not evident during non-academic tasks (ADHD) |
ASD | Inattention, social dysfunction and behavioural outbursts | Due to inability to tolerate a change from their expected course of events (ASD) Due to impulsivity or poor self-control (ADHD) |
Reactive attachment disorder (RAD) | Social disinhibition | Lack of enduring relationships; no full ADHD symptom cluster (RAD) No lack of enduring relationships; full ADHD symptom cluster (ADHD) |
Anxiety disorders (Anx) | Inattention | Due to worry and rumination (Anx)Due to attraction to external stimuli, including new or enjoyable activities (ADHD) |
Depressive disorders (Dep) | Inability to concentrate | Prominent only during depressive episode (Dep) Always present (not episodic) (ADHD) |
Bipolar disorder (BD) | Increased activity, poor concentration and impulsivity | Accompanied by elevated mood and grandiosity occurring in episodes that last a minimum of several days; rare in preadolescence (BD) Significant mood change within same day (ADHD) |
Personality disorders (PD) | Disorganisation, social intrusiveness, emotional dysregulation and cognitive dysregulation | Other clinical feature of borderline, narcissistic and other personality disorders (PD) No fear of abandonment, self-injury or extreme ambivalence (ADHD) |
Concussion (CC) | Poor concentration, memory deficits and mood fluctuation | Decline in neurocognitive testing after head injury compared with baseline (CC) No change of neurocognitive function in tests (ADHD) |