| Etiopathogenics factors | Types and evidences |
| Molecular genetic studies | Twin studies |
| High heritability (70%) | |
| Psychiatric Genetics Consortium(PGC) | |
| First-degress relatives with ADHD | |
| Parental psychopathology | |
| Candidate-gene studies | DAT1, DRD4, 5-HTT, COMT, MAOA,SLC6A2/NET, DRD2, XKR4, NPSR1, CNR1, DCDC2, GRIN2B |
| Environmental risks | Expose to alcohol |
| Maternal smoking during pregnancy | |
| Prematurity | |
| Low weight birth | |
| Stressful life events | |
| Emotional deprivation | |
| Childhood maltreatment subtypes | |
| Overlap with genetic conditions | Genetic syndromes |
| Bipolar disorders | |
| Autism Spectrum Disorders | |
| Intellectual Disorders | |
| Languagem Disorders |