The fact that multiple psychiatric diagnoses are often given to one person is well known and of concern within the psychiatric community. This situation occurs at much higher rates than would be expected by chance. This is a sign that something is not defined properly.
In medicine (as opposed to psychiatry), diagnoses are validated. This means that the “boundaries” of the condition are defined to a degree, or in a manner, that proves it is unique and separate from other conditions. Often this comes from identifying a biomarker that, when present, means it must be this condition rather than that condition. Certainly there are medical conditions for which an accurate diagnosis is not yet known and assignment of the wrong diagnosis or no diagnosis is possible. But the overwhelming majority of diagnoses that are made are made with the confidence that comes from an evidence-based knowledge of the biology and/or physiology associated with the condition.
In contrast, only one or two out of the hundreds of psychiatric disorders have been validated. At this point in time, the rest are all still conceptual. The fact that simultaneous, or co-morbid, diagnoses are more the rule than the exception, or that a diagnosis given today by one clinician could be changed to something else tomorrow by another clinician, would seem to be proof that the boundaries of the different disorders remain quite unclear.
Further, the frequency of co-morbidity between certain disorders is greater than it is between other disorders. This “bundling” may indicate a commonality between the disorders that is not adequately interpreted under the current classification system.
Research pursued by investigators of the JBRF Research Consortium indicates that many of the symptoms of disorders considered co-morbid to bipolar disorder (mania, major depression, separation anxiety disorder, obsessive-compulsive disorder, oppositional defiant disorder, conduct disorder and attention deficit disorder) may actually belong under the umbrella of a single disorder which they call Fear of Harm (FOH). To put that backwards, symptoms of a single disorder have been cleaved apart into separate diagnoses. The fact that those symptoms, in essence, keep unifying themselves through co-morbidity suggests that they are not really separate at all: an assertion supported by the observation that when children described by FOH are effectively treated, the entire group of symptoms goes away and, when the treatment wears off, the entire set of symptoms return.
If it is true that the boundaries placed between conditions are wrong, the risks are twofold:
- treatment may never appropriately target the single illness that actually exists, and
- treatments selected to target one of the earlier emerging group of symptoms may be contraindicated for the symptoms that will emerge later.