Attention-deficit/hyperactivity disorder (ADHD) often occurs with coexisting conditions. Fifty percent to 60% of children with ADHD have at least one coexisting condition. More than 10% of children with ADHD have 3 or more coexisting conditions. Disruptive behavior disorders (disorders involving behavior and conduct problems), anxiety and depressive disorders, learning disabilities, and language impairments are the most common.
Coexisting conditions may share many of the same symptoms or mimic the symptoms of ADHD. Coexisting conditions in young children with ADHD are particularly hard to identify correctly because children’s behavior changes quickly and certain conditions only become diagnosable over time. What seemed at 4 years of age to be a developing mood disorder may turn out to be aspects of ADHD.
In addition to diagnosed disorders, many children with ADHD experience coexisting “problems”—functioning difficulties that are not formally defined as disabilities but that still require special attention. For example, up to 60% of children with ADHD experience some form of academic problem in school subjects (reading, math, social studies, etc), skills (such as handwriting), or productivity (completing assignments accurately and on time), and most of these children do not have learning disorders.
In many cases—as with learning disorders that impede school performance—a coexisting condition or problem may affect your child’s functioning in ways that require changes in his education or treatment plan. Sometimes, as can be the case with major depressive disorder (MDD), the symptoms of the coexisting condition may be more problematic than those of the ADHD and must be treated first, even if the ADHD was the original cause of your child’s referral for treatment. In addition, a child’s environment may play an important role. The behavior of a child with ADHD may, at times, cause stress within the family or may reflect stress within the family, resulting in greater severity of the child’s symptoms.
Some conditions, such as conduct disorder, which involves extreme defiance and flaunting of rules, carry increased risks for substance abuse, criminal behavior, or other difficulties later in life—risks that may be diminished or even avoided if the condition is identified early and treated. For all of these reasons, it is always necessary to consider whether any of these coexisting conditions are present when your child is being evaluated for ADHD, and a comprehensive evaluation and ongoing monitoring are needed to diagnose any additional conditions and problems that can accompany ADHD. Continued monitoring is vital throughout childhood and adolescence because some coexisting conditions may develop long after the original ADHD diagnosis and others may diminish over time. In this chapter you will find information on how best to recognize and treat the types of coexisting conditions that most commonly accompany ADHD, including
Disruptive behavior disorders, including oppositional defiant disorder (ODD) and conduct disorder (CD)
Anxiety disorders, such as generalized anxiety disorder, separation anxiety disorder, phobias, and post-traumatic stress disorders
Mood disorders, including MDD, dysthymia, and bipolar disorder
Tics, Tourette disorder, and obsessive-compulsive disorder (OCD)
Learning, motor skills, and communication disorders
Intellectual disability (formerly called mental retardation)
Autism spectrum disorders (ASDs), pervasive developmental disorders (PPDs), such as autism and related disorders
Coexisting problems that, while not reaching the severity required for a specific diagnosis, may still significantly stand in the way of your child’s progress
There are other problems that might either look very similar to ADHD, or make the symptoms of ADHD stand out more. These include
Sensory deficits, such as hearing or vision problems
Sleep deprivation
Bereavement
Certain physical illnesses (eg, thyroid disease, hypoglycemia, hyperglycemia, side effects of medications, and endocrine tumors)
Substance use or withdrawal from substances
Exposure to adverse childhood experiences
When viewed all together, this list of disorders may seem daunting, and even frightening. Keep in mind, however, that although concurrent conditions occur in most children and adolescents with ADHD, no child has all of these conditions, and most are treatable. With early identification and a systematic evidence-based treatment program, you and your child may be able to avoid or minimize many of the effects of disorders that do appear. Furthermore, the strengths of your child and family are important factors in increasing the likelihood that he will function well, despite these conditions.
