Table 2. Summary of some of the studies used in reviewing the comorbidity of ADHD, ODD, and CD.

ADHD: attention deficit hyperactivity disorder, ODD: oppositional defiant disorder, CD: conduct disorder

Author name	Year of publication	Study design	Sample size (if applicable)	Conclusions
Van Lier et al. [28]	2007	Observational study (cross-sectional)	2,076	ADHD commonly occurs with CD. The presence of ODD predicts this occurrence in children and adolescents. There is a gender difference in the occurrence of CD.
Ghosh et al. [29]	2012	Case report	3	ADHD, ODD, and CD share common developmental pathways and symptoms; therefore, these findings suggest a common psychopathological spectrum in these disorders.
Ahuja et al. [30]	2013	Observational study (cross-sectional)	1,029	Children with ADHD and intellectual disability have high rates for comorbid CD and ODD.
Padhy et al. [11]	2015	Review	Not applicable	Reading disability commonly occurs with psychological comorbidities, such as internalizing disorders (depression and suicide) and externalizing disorders (ADHD, ODD, and CD).