Testing to Find the Cause of ADHD
Some studies have demonstrated that allergy and toxins that may cause ADHD may respond to the elimination of the toxin or allergy. Neurotransmitter testing can sometimes guide physicians in the use of stimulant vs. non-stimulant treatment, and functional MRI can sometimes identify specific areas in the brain that are undeveloped and would benefit from brain plasticity type exercises targeted to strengthen the underdeveloped brain area.
Most physicians who diagnose ADHD do not do any testing. They tend to use the stimulant therapy as first line treatment and only look for alternatives if the stimulants cause side effects or fail to address the symptoms of ADHD. This may be the fastest, most cost effective and least invasive approach as most people with ADHD will respond to stimulant treatment.
The reasons that physicians choose to treat first and test later is related to many factors that include cost, expediency, probabilities, and patient comfort. Whether this lack of testing is 'right' or 'wrong' is a complex question but I I see a parallel here to the current methods used in the evaluation and treatment of high blood pressure. I know that most of you are not reading this to learn about high blood pressure but please stay with me here for just a moment.
In about 90% of cases of hypertension the cause is unknown. This type of hypertension is called essential hypertension and researchers have found multiple drug treatments that effectively treat essential high blood pressure. Some factors make high blood pressure worse such as hardening of the arteries and fluid retention and some drug treatments for hypertension also address these contributing factors.
In the rest of the cases of hypertension, the high blood pressure is caused by an underlying problem such a kidney or heart abnormality or an adrenal tumor. This type of hypertension is called secondary hypertension and the best treatment for this type of high blood pressure is the treatment of the underlying problem.
Many physicians do not do adrenal scans or many other tests prior to placing patients on blood pressure medication for the same reasons that ADHD physicians don't. It is more cost effective, faster, and less invasive to just write a prescription and not bother to tease out the reason or cause of of the ADHD. The problem with this approach is that the diagnosis of secondary hypertension can be missed. This is especially true if the patient’s blood pressure responds well to the prescription medication. The underlying cause of secondary hypertension can go untreated for years until the patient develops more problems or worsens as a result of the real cause for the high blood pressure
I work in the health care field and I know that getting lab tests for allergy, neurotransmitters or toxins or getting scans and MRIs is far easier said than done. Some of the barriers to this type of testing involve costs. Insurance companies will rarely pay for these types of tests for ADHD. Another barrier is finding a physician willing to do and interpret these tests and yet another barrier is the willingness of patients and parents to submit to this type of testing.
For most patients with ADHD, the cause will be unknown even if they are tested. They have what I would call, using my hypertension model, "Primary ADHD". Many of these same patients will respond to lifestyle changes, dietary interventions, coaching, and/or medication.
But how about the folks with "Secondary ADHD"? The decision to routinely do more testing for the underlying causes of ADHD and to discover the individuals with "secondary ADHDs" ( and the logistics of implementing this type of testing universally) are complicated but I doubt that any one would argue that "Secondary ADHD" needs to be diagnosed and treated.
Ongoing research will likely guide us in answering these testing questions, until then I would love to hear your opinion on screening and evaluation tests for ADHD.