Imaging and signal processing technologies play a critical role in many medical diagnoses. However, these tools have not yet been utilized to aid in the clinical diagnosis or treatment of neurocognitive disorders such as Attention Deficit Hyperactivity Disorder (ADHD). This paper reviews research literature investigating the potential ADHD diagnosis and treatment efficacy of various imaging and signal processing modalities. The benefits and drawbacks of each modality are then summarized and compared by a decision matrix wherein the viability of a computer vision modality is highlighted. Finally, the paper suggests a general system design for a modality that uses computer vision and that can be used along with neuropsychological assessments for the diagnosis and treatment of ADHD.