The current version of the Diagnostic and Statistical Manual of Mental Disorders, 5th ed. (DSM-5), is atheoretical, which means that it . does not speculate as to the causes of an individual's behavior does not require that the disorder symptoms interfere with a person's ability to function undermines the complex biopsychosocial nature of the causes of mental illness fails to indicate the length of time that a person must show the symptoms to qualify for a diagnosis