Executive Function & ADHD

The executive system controls both input – whether we attend to an event or ignore it,  and output – whether we initiate a response or inhibit it.  You may have heard of attention deficit/hyperactivity disorder, or ADHD (I’d be surprised if you hadn’t!), or “executive dysfunction.” Both involve problems with control – poor concentration and distractibility, and poor impulse control, or impulsivity.  I am concerned that this “diagnosis” is tremendously overused (as are the stimulant medications prescribed to treat it), and that problems with executive function are poorly understood. The Executive system is very vulnerable, because it requires optimal functioning. We have to be at our best, “firing all cylinders” for it to work well. If we are tired, sick, anxious or depressed, we can’t focus, and we can’t plan, we can’t get started, and we can’t problem solve. So executive dysfunction is actually a symptom of lots of different things. A primary deficit of executive function deficit, that is, not caused by another condition, is actually quite rare.

How Attention works and why it often doesn’t

There are two sources of input to the brain via the Sensory system – from the external environment (the world) and the internal environment (the body). The brain’s job is to integrate this information so that the needs of the body can be matched with the opportunities in the environment.  Because we humans are highly evolved organisms who navigate a very complex environment, we need to filter much of the information available and prioritize our needs. It is the job of the Executive system – the process of attention – to enable us to ignore unimportant events (like the hum of the refrigerator) and focus on the most important event (making the sandwich).  And, if a grisly bear were to step into the kitchen, our Affective system would quickly downgrade the priority of the sandwich – in light of the bear – resulting in a shift of both our attention and our behavior. So the Affective system drives the Executive system – emotion directs attention.  The result is that we have great difficulty paying attention to something if it is not the most emotionally important thing going on.  The problem is that much of the time we are not in control – or even aware – of what is most emotionally important to us at a given moment.