The present specification discloses systems and computer implemented assessment methods including a system and method of assigning an individual to a group participating in a clinical study regarding a psychotic disorder, a system and method of determine whether and what type of psychotic disorder an individual may be suffering from; and a system and method of recommending a therapy to treat an individual with a psychotic disorder. All disclosed systems and computer implemented assessment methods use a non-invasive computational device-based test that uses a graphical user interface to measure a latent inhibition response of an individual to calculate a latent inhibition score and assess working memory. The latent inhibition score determines whether the individual exhibits an attenuated latent inhibition response, a normal latent inhibition response or an enhanced latent inhibition response.