AS many as 5% of adults have ADHD. The diagnosis implies that the disorder was present since childhood. One study has found that anxiety is a condition with a prevalence of almost 34% in ADHD. In fact, anxiety and ADHD can occur together in 28% boys and 33% girls. This is far higher than the prevalence in children without this condition.
Adults with persistent ADHD have anxiety disorders in over 40% and 50% in men and women, respectively. One in eight of these patients has generalized anxiety disorder (GAD). The converse is also true. Adults with depression or anxiety have a much higher prevalence of ADHD than controls. But are these truly comorbid conditions, that is, psychiatric conditions, which occur in the same patient, but have no other relation?
It is now known that these are no independently arising conditions in many patients. Instead, the anxiety is usually a result of ADHD, which impairs the adult’s functioning seriously to a level where the individual can no longer function without great stress. Thus it is a partial consequence of the ADHD in many cases, a result of the individual’s feeling of helplessness and inability to escape from the ADHD-induced social, occupational and personal incompetence. The chronic feeling of failure removes all motivation or ability to do any better.
In most cases, the presence of coincident anxiety can be ruled out using the Structured Clinical Interview for DSM-IV Axis I Disorders. Another set of conditions is not consistent with the criteria for anxiety, but causes subjective feelings of poor functioning known to be due to the ADHD. This may form a whirlpool of anxiety, which further worsens executive functioning and attention, eventually obscuring the cause altogether. The content of anxious feelings in ADHD-induced anxiety is usually related to their inability to meet the demands they face, because of their ADHD-associated inefficiency. Unlike that of a primary anxiety disorder, this is not unrealistic or non-existent fear, but one with a real content.
The implication of the present state of knowledge of these co-occurring conditions is that treatment needs to be focused on the ADHD rather than on the overlying anxiety, as the former choice will effectively eliminate both. Any other mode of therapy runs the risk of treating the wrong end of the problem.
A second reason to focus on treating the ADHD first before the anxiety is the much faster and stronger positive response to the former, making it far more cost-effective and providing the answer to the question, which to treat first.
Again, it is essential to screen all anxious patients for ADHD as well, as the latter is a marker for conditions including the former.
Treatment of ADHD usually begins with medications, of which one very effective drug to date has been found to be methylphenidate. How much the presence of anxiety alters the patient’s response is still unknown. Available data suggests a worse response in children with ADHD and anxiety, and a higher susceptibility to the development of side effects such as tics. The analysis of this data is further complicated by the fact that improvement in either condition will of course lead to a corresponding improvement in the other, because of the close relationship of many symptoms of either.
A classic instance is the reduction in inattention and forgetfulness when a constant worrying state is relieved by appropriate pharmacotherapy. Another problem is that most scales to measure the effect of treatment in ADHD complicated by anxiety focus on measures not specific to anxiety, such as sleep or digestive complaints, rather than worry-related complaints, which are pathognomonic of the condition. For example, social anxiety could be either due to fear of what others may think of them, which is more characteristic of true anxiety, or because of a history of social embarrassment and upsets caused by ADHD behaviors. More precise scales, which exclude ADHD-induced complaints, are therefore necessary to assess the results of intervention in this combined disorder.
Combinations of selective serotonin reuptake inhibitors (SSRIs) or buspirone for anxiety, with stimulants such as methylphenidate, are often used. However, cognitive behavioral therapy seems to have an equal effect on relieving both anxiety and ADHD manifestations in these children, even though the treatment focuses on only ADHD symptoms. It has been found that combination treatment has a higher risk of adverse reactions and psychiatric events than when a single drug was used. Combining one drug with psychosocial interventions for anxiety as well as some features of ADHD may be the best treatment modality for one subcategory in this group of children.
ADHD often acts as a roadblock in the internalization or practice of CBT in patients who have both this condition and anxiety, until the former is controlled. CBT acts especially well in adult ADHD patients who have better insight into their deficits and the problems they face as a result, which provides great motivation and need for the treatment. Combined with executive skill training, it helps these patients to learn how to do better work more easily by using strategy, planning, and organizing skills in their tasks, in order of priority.