University of Minnesota Ph.D. dissertation.August 2017. Major: Computer Science. Advisor: Nikolaos Papanikolopoulos. 1 computer file (PDF); viii, 99 pages.Mental health disorders are the leading cause of disability in the United States and Canada, accounting for 25 percent of all years of life lost to disability and premature mortality (Disability Adjusted Life Years or DALYs). Furthermore, in the United States alone, spending for mental disorder related care amounted to approximately $201 billion in 2013. Given these costs, significant effort has been spent on researching ways to mitigate the detrimental effects of mental illness. Commonly, observational studies are employed in research on mental disorders. However, observers must watch activities, either live or recorded, and then code the behavior. This process is often long and requires significant effort. Automating these kinds of labor intensive processes can allow these studies to be performed more effectively. This thesis presents efforts to use computer vision and modern interactive technologies to aid in the study of mental disorders. Motor stereotypies are a class of behavior known to co-occur in some patients diagnosed with autism spectrum disorders. Results are presented for activity classification in these behaviors. Behaviors in the context of environment, setup and task were also explored in relation to obsessive compulsive disorder (OCD). Cleaning compulsions are a known symptom of some persons with OCD. Techniques were created to automate coding of handwashing behavior as part of an OCD study to understand the difference between subjects of different diagnosis. Instrumenting the experiment and coding the videos was a limiting factor in this study. Varied and repeatable environments can be enabled through the use of virtual reality. An end-to-end platform was created to investigate this approach. This system allows the creation of immersive environments that are capable of eliciting symptoms. By controlling the stimulus presented and observing the reaction in a simulated system, new ways of assessment are developed. Evaluation was performed to measure the ability to monitor subject behavior and a protocol was established for the system's future use
