ADHD diagnosis is a rather difficult task for the clinician, although there are established guidelines and universally accepted diagnostic criteria for it. The reason is that many of the symptoms of the disorder overlap with those of comorbids and hinder the diagnostic procedure. Because of this heterogeneity of ADHD symptoms, the diagnosis should be made as early as possible by a specialized multidisciplinary team, in collaboration with the family and educators. This approach gives the chance to the health care providers to consider all the behavioral parameters of the child, the environment and the underlying conditions that may be associated with ADHD or be a result thereof.
The clinical picture of ADHD is variable, according to the individual’s developmental stage. The pre-school age (3-5 years) is characterized by hyperactivity, difficulty in cooperating with peers and inability to comply with adults’ recommendations. During the school age (6-12 years), besides the core symptoms, e.g. inattention, hyperactivity, and impulsivity, children with ADHD often present with oppositional disorder, conflicts with peers and problems at school. In puberty, hyperactivity starts declining in some cases; however conflicts and often a high a risk behavior appear. In adulthood, the excessive motion is progressively declining, though the inattention and the impulsivity remain, therefore, the impact of the disorder on the dysfunctioning family is obvious.
Τo diagnose a child or an adolescent as having ADHD he or she should display at least 6 of the core symptoms described in the taxonomic systems for at least 6 months, before the age of 7 years, and he/she should not suffer from any other medical or mental disorder which could explain such a behavior. The behaviors must occur and negatively affect at least two areas of a child's life, e.g. school, home, day-care settings, or friendships.
The diagnosis of the adult ADHD is a rather complicated procedure and requires specialized methodology. Unfortunately, the experience in the field of diagnosis and treatment is limited amongst adult psychiatrists and other health care personnel. For the proper clinical diagnosis of adult ADHD, the pre-existing history of childhood ADHD, as well as the coexistence of one or more comorbidities in childhood and adulthood is of major importance.