As I've written in earlier entries, symptoms of ADHD are shared by several psychiatric disorders, and parents are sometimes worried that their children are misdiagnosed with ADHD. In particular, depression in children shares several symptoms with ADHD and depressed children can look and behave much differently than depressed adults. Loss of interest, lack of energy, and fatigue are experienced in children who have depression.
These symptoms can appear similar to the hesitance to start activities that require sustained mental effort or inability to finish activities which are classic symptoms of ADHD in the class room. The lack of energy and the impairment in thinking that sometimes occurs with depression can be almost indistinguishable from difficulty organizing activities and thoughts associated with ADHD.
In depressed children, irritability can be more striking than depressed mood. Constant complaining in an agitated voice, difficulty tolerating frustration, and insomnia can overshadow feelings of guilt and worthlessness in depressed children leading parents and teachers to believe they have ADHD. It takes time and careful consideration to distinguish the excessive talking often seen in ADHD with the sometimes relentless, animated complaining that some depressed children engage in.
There are some features of depression that distinguish it from ADHD. Anorexia is not specifically a symptom of ADHD but can occur in childhood-onset depression, however it's important to note that stimulant medication can suppress appetite. While many children with depression appear hyperactive, symptoms like lack of speech, excessive fatigue, and a general slowness of movement, if present, are more suggestive of a mood disorder like depression rather than ADHD. Many children with ADHD have some guilt due to their hyperactive and inattentive behavior in the classroom and at home, however pervasive guilty feelings, particularly when they occur with serious thought of killing oneself is a sign that the child has a serious depression.
As you can guess, the task of determining whether a child is depressed or has ADHD can become complicated sometimes. A sizeable percentage of children with ADHD have a second psychiatric disorder like depression, and children with both disorders can be quite challenging for their families. The good news is that many good therapies and medications exist to treat these disorders. Anxiety disorders, autism, psychosis and sleep deprivation all have some symptoms which overlap with ADHD. Future entries may address these specific disorders; however I am interested in hearing your questions and comments.