Table 2.
ADHD subtypes, symptom frequencies and age of symptom onset
| Number of symptoms * | Age at first symptom detection° | |||||||||||||||||
| Boys | ||||||||||||||||||
| Inattention | Hyperactivity/Impulsivity | Inattention | Hyperactivity/Impulsivity | |||||||||||||||
| Status | ADHD subtype | N | Mean t | CI low | CI up | Range | Mean t | CI low | CI up | Range | Mean t | CI low | CI up | Range | Mean t | CI low | CI up | Range |
| Siblings | No Diagnosis | 39 | 6.28 | 5.24 | 7.24 | 0 - 9 | 4.60 | 3.32 | 5.92 | 1 - 9 | 6.20 | 5.00 | 7.75 | 1 - 15 | 3.50 | 2.13 | 5.19 | 1 - 13 |
| Hyperactive/Impuslive | 15 | 4.33 | 3.56 | 5.00 | 1 - 5 | 7.89 | 6.89 | 8.56 | 6 - 9 | 4.75 | 3.63 | 5.75 | 1 - 9 | 2.89 | 2.11 | 3.78 | 1 - 6 | |
| Inattentive | 43 | 7.59 | 7.11 | 8.07 | 6 - 9 | 3.96 | 3.41 | 4.41 | 1 - 5 | 4.38 | 3.85 | 4.96 | 1 - 6 | 3.67 | 2.90 | 4.43 | 0 - 10 | |
| Combined | 118 | 8.47 | 8.21 | 8.69 | 6 - 9 | 8.40 | 8.17 | 8.56 | 6 - 9 | 4.06 | 3.63 | 4.44 | 1 - 10 | 2.94 | 2.49 | 3.39 | 1 - 7 | |
| All subtypes | 215 | 7.88 | 7.60 | 8.13 | 0 - 9 | 7.22 | 6.74 | 7.60 | 1 - 9 | 4.42 | 4.14 | 4.70 | 1 - 15 | 3.11 | 2.74 | 3.46 | 0 - 13 | |
| Probands | Combined | 938 | 8.50 | 8.42 | 8.58 | 6 - 9 | 8.47 | 8.39 | 8.55 | 6 - 9 | 4.23 | 4.10 | 4.35 | 0 - 12 | 2.41 | 2.27 | 2.55 | 0 - 11 |
| Girls | ||||||||||||||||||
| Inattention | Hyperactivity/Impulsivity | Inattention | Hyperactivity/Impulsivity | |||||||||||||||
| Status | ADHD subtype | N | Mean t | CI low | CI up | Range | Mean t | CI low | CI up | Range | Mean t | CI low | CI up | Range | Mean t | CI low | CI up | Range |
| Siblings | No Diagnosis | 40 | 4.21 | 3.33 | 5.17 | 0 - 9 | 3.04 | 2.21 | 3.83 | 0 - 9 | 6.32 | 5.32 | 7.63 | 1 - 16 | 4.71 | 2.86 | 7.29 | 1 - 15 |
| Hyperactive/Impuslive | 11 | 4.00 | 2.57 | 4.71 | 1 - 5 | 6.86 | 6.29 | 7.57 | 6 - 9 | 3.60 | 2.40 | 6.80 | 1 - 11 | 3.57 | 2.14 | 5.00 | 1 - 6 | |
| Inattentive | 33 | 7.38 | 6.95 | 7.86 | 6 - 9 | 3.24 | 2.43 | 3.90 | 1 - 5 | 5.26 | 4.74 | 5.74 | 1 - 6 | 3.40 | 2.20 | 4.60 | 1 - 6 | |
| Combined | 40 | 8.33 | 7.92 | 8.71 | 6 - 9 | 8.38 | 7.96 | 8.71 | 6 - 9 | 4.13 | 3.29 | 4.83 | 0 - 8 | 2.42 | 1.75 | 3.29 | 0 - 6 | |
| All subtypes | 124 | 6.76 | 6.22 | 7.30 | 0 - 9 | 5.20 | 4.50 | 5.88 | 0 - 9 | 4.91 | 4.49 | 5.31 | 0 - 16 | 3.16 | 2.53 | 3.81 | 0 - 15 | |
| Probands | Combined | 130 | 8.27 | 8.04 | 8.49 | 6 - 9 | 8.38 | 8.13 | 8.62 | 6 - 9 | 4.10 | 3.75 | 4.43 | 0 - 12 | 1.97 | 1.64 | 2.35 | 0 - 11 |
| All | ||||||||||||||||||
| Inattention | Hyperactivity/Impulsivity | Inattention | Hyperactivity/Impulsivity | |||||||||||||||
| Status | ADHD subtype | N | Mean t | CI low | CI up | Range | Mean t | CI low | CI up | Range | Mean t | CI low | CI up | Range | Mean t | CI low | CI up | Range |
| Siblings | No Diagnosis | 79 | 5.27 | 4.49 | 5.98 | 0 - 9 | 3.63 | 2.96 | 4.35 | 0 - 9 | 6.19 | 5.35 | 7.24 | 1 - 16 | 3.93 | 2.87 | 5.43 | 1 - 15 |
| Hyperactive/Impuslive | 26 | 4.19 | 3.50 | 4.69 | 1 - 5 | 7.38 | 6.81 | 8.06 | 6 - 9 | 4.31 | 3.38 | 5.46 | 1 - 11 | 3.13 | 2.38 | 3.94 | 1 - 6 | |
| Inattentive | 76 | 7.50 | 7.13 | 7.89 | 6 - 9 | 3.67 | 3.17 | 4.11 | 1 - 5 | 4.80 | 4.36 | 5.20 | 1 - 6 | 3.56 | 2.85 | 4.24 | 0 - 10 | |
| Combined | 158 | 8.44 | 8.23 | 8.66 | 6 - 9 | 8.40 | 8.19 | 8.55 | 6 - 9 | 4.07 | 3.73 | 4.44 | 0 - 10 | 2.81 | 2.41 | 3.22 | 0 - 7 | |
| All subtypes | 339 | 7.56 | 7.27 | 7.79 | 0 - 9 | 6.53 | 6.10 | 6.92 | 0 - 9 | 4.59 | 4.36 | 4.82 | 0 - 16 | 3.09 | 2.78 | 3.41 | 0 - 15 | |
| Probands | Combined | 1068 | 8.48 | 8.39 | 8.55 | 6 - 9 | 8.46 | 8.38 | 8.54 | 6 - 9 | 4.22 | 4.10 | 4.33 | 0 - 12 | 2.36 | 2.23 | 2.48 | 0 - 11 |
* Frequencies are based on the combination of the parental Interview (PACS) and the teacher questionnaire (CTRS)
° As reported by the PACS
Mean t 20% trimmed mean
CI low 95% confidence interval for trimmed mean (lower end)
CI up 95% confidence interval for trimmed mean (upper end)