Since attention deficit disorder, or ADD, is a syndrome or collection of symptoms, it can be difficult to diagnose. Online tests are useful as a screening aid, but there is no single diagnostic test for attention deficit disorder, according to the Centers for Disease Control and Prevention.
If online test results are indicative of attention deficit disorder, consult an experienced professional such as a psychologist or psychiatrist for a detailed evaluation and treatment plan. The American Psychiatric Association's "Diagnostic and Statistical Manual of Mental Disorders" specifies a list of possible symptoms that may occur in different settings, notes the CDC. The manual is occasionally updated so diagnostic criteria may vary over time. In addition, it can be difficult to distinguish between attention deficit disorder and other problems such as anxiety or depression.