Attention-deficit\/hyperactivity disorder (ADHD) is a condition that begins in childhood and produces varying combinations of classic symptoms such as a reduced ability to maintain attention, diminished behavior control, and unusual bouts of overactivity. Prior to May 2013, the American Psychiatric Association\u2019s Diagnostic and Statistical Manual of Mental Disorders (DSM) contained a definition for ADHD that was highly geared toward children. However, as a result of a new understanding regarding the effects of ADHD in adults, the newest version of the Diagnostic and Statistical Manual (DSM 5) also contains a modified ADHD definition for adult cases of the disorder. ADHD Basics ADHD comes in three basic forms or subtypes, the National Institute of Mental Health explains. Some people have predominantly hyperactive-impulsive ADHD, a condition that requires the presence of at least six hyperactive-impulsive symptoms for a childhood diagnosis. Examples of the required symptoms include extreme impatience, incessant talking, an inability to sit still or stop moving, an inability to control displays of emotion, frequent interruption of others, problems participating in quiet or silent situations, and a tendency to act without thinking. Other people have predominantly inattentive ADHD, a condition that requires the presence of at least six symptoms of inattention for a childhood diagnosis. Examples of the required symptoms include easy boredom, problems completing tasks or homework, problems focusing during tasks or conversations, difficulty carrying out instructions, lack of responsiveness during conversations, problems taking in new information, general distractibility, and a tendency to forget or fail to detect the fine points of a conversation or situation. The third subtype of ADHD, called combined hyperactive-impulsive and inattentive ADHD, features problems related to both of the disorder\u2019s other two subtypes. In order to qualify for a diagnosis, affected people must have at least six hyperactive-impulsive symptoms and at least six inattentive symptoms. In all cases, individuals diagnosed with ADHD must have levels of hyperactivity, impulsivity and\/or inattention that are unusual for their age. They must also experience the effects of their symptoms for a minimum of half a year. Adult ADHD Basics For a long time, doctors believed that ADHD occurs only in children, the Mayo Clinic explains. However, while the condition always begins in childhood, cases diagnosed in childhood sometimes produce effects that extend well into adulthood; in addition, some cases of the disorder go undiagnosed until an individual reaches adulthood. Apart from the problems commonly associated with childhood ADHD\u2014such as substandard academic performance and a poorly develop sense of self-respect\u2014adult ADHD can produce problems that include a reduced ability to get or keep a job, volatile personal relationships, unpredictable swings in mood or temperament, and a poor ability to deal with the everyday stresses of adult life. Since ADHD symptoms sometimes fade away over time, adults with the disorder often have fewer symptoms than children with the disorder. New DSM 5 Definition The definition for ADHD contained in the now obsolete fourth edition of the Diagnostic and Statistical Manual (DSM IV) follows the same general guidelines that doctors use outside of the mental health community. However, the DSM IV definition also adds several additional criteria. First, affected individuals must develop at least some of their ADHD symptoms before they reach their eighth birthdays. These symptoms must also significantly disrupt the ability to participate in one or more aspects of work life, school life, or general social interaction. In addition, people diagnosed with ADHD must not have symptoms that can be essentially explained by other mental health issues such as bipolar disorder, schizophrenia, a personality disorder, or a condition called a dissociative disorder. The DSM 5 definition for ADHD changes the DSM IV definition in several ways. First, while children age 17 or younger must still have six or more symptoms of hyperactivity, impulsivity and\/or inattention to qualify for a diagnosis, adults and teenagers over the age of 17 must only have five or more of any of these symptoms to qualify for a diagnosis. This change was made specifically to acknowledge the fact that adults can still be significantly affected by ADHD; it was also made to acknowledge the fact that adults with ADHD sometimes have fewer and\/or different symptoms than their child counterparts. The DSM 5 definition for attention-deficit\/hyperactivity disorder also raises the maximum age for the initial onset of symptoms from 7 to 14. While the new definition still requires that ADHD patients not have a number of other mental health problems that can potentially explain their symptoms, affected individuals can still receive an ADHD diagnosis if they have autism spectrum disorder.