1. In an image recognition system comprising an image graph constructor and a comparison module, a method for detecting target disorders, comprising: optically scanning a plurality of writing samples for each of a plurality of known subjects; storing the optically scanned writing samples in a database; grouping the samples chronologically; analyzing the optical scanned writing samples to detect trends, wherein analyzing the optical scanned writing samples includes: converting the optical scanned writing samples into a plurality of image graphs comprising edges and vertices using the image graph constructor, traversing each of the plurality of image graphs to capture data related to various geometric features included in the graphs, and comparing the data related to the various geometric features for the plurality of image graphs using the comparison module and assigning a value to each geometric feature for each of the plurality of image graphs, the assigned values being used to determine whether a trend in the writing samples associated with a given target disorder can be discerned.