Characteristics of the Study Cohort

CharacteristicEntire CohortChildren With ADHD at Time 2 (n = 62)Children Without ADHD at Time 2 (n = 26)Pa
Age at diagnosis, mo68.1311.3568.2511.7868.939.73.778
Age at time 2, mo150.8924.36150.2024.74153.0424.19.618
Percent living below poverty level8.558.499.088.927.045.73.202
Nonverbal cognitive composite93.1617.3690.0015.8795.1114.08.154
Income-to-needs ratio4.403.752.902.017.694.55<.001***
Presence of comorbid condition91/12075.8345/6272.5821/2680.77.418
At least 1 externalizing subscale with T score >7059/12049.2039/6262.906/2623.08.001**
At least 1 internalizing subscale with T score >7019/12015.8012/6219.352/267.69.172
Race (non-Hispanic white)64/8872.7342/6267.7422/2684.62.105
Maternal education (up to high school)18/8820.4516/6225.813/2611.54.138
Paternal education (up to high school)27/8830.6826/6241.944/2615.38.017*
Parental report of psychopathology77/17643.7568/12454.849/5217.31<.001***
Parental report of anxiety and/or depression60/17634.0954/12443.556/5211.54<.001***
Parental report of bipolar disorder10/1765.688/1246.452/523.85.496
Parental report of schizophrenia7/1763.986/1244.841/521.92.367
Parental report of substance abuse24/17613.6416/12412.908/5215.38.662
Parental report of ADHD93/17652.8482/12466.1311/5221.15<.001***
  • * P < .05, **P < .01, ***P < .001.

  • a To compare children with and without ADHD at time 2, t tests and χ2 statistics were used.