Utilization behaviour is thought to occur because an action is initiated when an object is seen, but patients with DES lack the central executive control to inhibit acting it out at inappropriate times.Perseveration is also often seen in patients with DES. Perseveration is the repetition of thoughts, behaviours, or actions after they have already been completed. For instance, continually blowing out a match, after it is no longer lit is an example of perseveration behaviour. There are three types of perseveration: continuous perseveration, stuck-in-set perseveration, and recurrent perseveration. Stuck-in-set perseveration is most often seen in dysexecutive syndrome. This type of perseveration refers to when a patient cannot get out of a specific frame of mind, such as when asked to name animals they can only name one. If you ask them to then name colours, they may still give you animals. Perseveration may explain why some patients appear to have obsessive-compulsive disorder. Comorbid disorders
DES often occurs with other disorders, which is known as comorbidity. Many studies have examined the presence of DES in patients with schizophrenia. Results of schizophrenic patients on the Behavioural Assessment of the Dysexecutive Syndrome (BADS) test (discussed below) are comparable to brain injured patients. Further, results of BADS have been shown to correlate with phases of schizophrenia. Patients in the chronic phase of the disorder have significantly lower scores than those who are acute. This is logical due to the similarities in executive disruptions that make everyday life difficult for those with  schizophrenia and symptoms that form DES.
The lack of everyday application of traditional tests is known as low ecological validity. Behavioural
The Behavioural Assessment of the Dysexecutive Syndrome (BADS) was designed to address the problems of traditional tests and evaluate the everyday problems arising from DES. BADS is designed around six subtests and ends with the Dysexecutive Questionnaire (DEX). These tests assess executive functioning in more complex, real-life situations, which improves their ability to predict day-to-day difficulties of DES. The six tests are as follows:Rule Shift Cards - Assesses the subjects ability to ignore a prior rule after being given a new rule to follow. Action Program - This test requires the use of problem solving to accomplish a new, practical task. Key Search - This test reflects the real-life situation of needing to find something that has been lost. It assesses  the patients ability to plan how to accomplish the task and monitor their own progress. Temporal Judgment - Patients are asked to make estimated guesses to a series of questions such as, "how fast do racehorses gallop?". It tests the ability to make sensible guesses. Zoo Map - Tests the ability to plan while following a set of rules. Modified Six Elements - This test assesses the subjects ability to plan, organize and monitor behaviour.The Dysexecutive Questionnaire (DEX) is a 20-item questionnaire designed to sample emotional, motivational, behavioural and cognitive changes in a subject with DES.