Dr. Grossi's Blog
In recent days I began to redesign the initial evaluation form used in the office for new patients entering the practice. As I began this project a friend of mine became gravely ill and is about to die. This sparked my thinking about the similarities between the methods used by the psychiatrist and those used by the historian. We both use the case history method in which the psychiatrist relies on the patient's report of his/her past whereas the historian relies on documents of various sorts to draw conclusions about either the psychological makeup of an alive patient or a dead historical figure. There are strengths and weaknesses with each approach.
For the purpose of the current psychiatric evaluation I am thinking in categorical terms mostly but some dimensional ones as well. What then are the pieces of evidence I seek to support the conclusions I reach and the treatment recommendations I make. First there are symptoms, sometimes referred to as complaints., These are often non-specific and this suggestive of certain disorders but nowhere hear definitive. Then there is the course of illness whose diagnostic importance is unappreciated by most mental health professionals. It generates many questions. What was the age of onset? Are the symptoms constant or episodic? Is the central problem over time one of mood? Is the central problem over time one of distorted thinking? Do thinking and mood problems co-occur at times? etc. etc. etc. Then there is the genetic window to peer through. Psychiatric problems tend to run in families and I often observe more assortative mating than I would expect in the families I see. Schizophrenia and bipolar disorder are highly heritable disorders. Unipolar depression is less heritable and the environment is a greater participant in producing the clinical presentation. The fourth area of evidence is drawn from treatment response. This area is more difficult to appraise because some people never seek treatment and others receive treatment which is inadequate thus making it problematic to draw a reasonably accurate and firm conclusion. Yet, there are circumstances when a startlingly effective and rapid response to treatment can clearly point to a diagnosis. We are looking at the drug or other intervention as a probe. In the case of medications, where this is easiest to see, we know how a drug works. When I see certain responses from drugs, I can reason backward to a condition because I usually know what the drug effects. For example, when using an antidepressant I might produce a phenomena known as switching, i.e., converting a depressed patient into a hypomanic or manic one. This would directly support a diagnosis of bipolar disorder and would help to clarify the distinction between unipolar depression and bipolar disorder or bipolar depression. In the case where some social engineering is involved, for example, in urging a patient to leave an unhealthy relationship, I might observe a reduced reliance on medication over time as well as greater happiness and productivity. The use of this framework allows for the making of a psychiatric diagnosis in keeping with the categorical schema set out in DSM5.
This case method and categorical diagnosis will gradually be giving way to diagnosis based on a constellation of symptoms PLUS various laboratory findings which could include blood values, genetic study findings, brain scanning and other brain study results etc. Indeed in the current DSM5 the B 2 and 3 criteria for narcolepsy cites hypocretin deficiency and nocturnal sleep study showing REM sleep latency of less than or equal to 15 minutes as diagnostic criteria. These are the first citations of laboratory values in the DSM series.
The Research Domain Criteria (RDoC) which I discussed in one of my earliest blogs, has as its goal building the linkage between symptom complexes and underlying pathological mechanisms. The RDoC will be attempting to link symptoms to more biological and less biologically restricted categorizations than is found in the DSM5. The RDoC framework includes dimensional concepts, e.g., negative valences,, positive valences, social processes, cognition and arousal that mesh psychological and biological phenomena. Several biological concepts in the RDoC include physiological and genetic concepts. The RDoC also includes psychological constructs and implicates the neural circuits that underlie them. This acts to narrow the focus of the DSM5 and therefore will allow better tracking of many clinical findings which vary throughout the population and become pathological only at the extremes of population distribution. The probable outcome of RDoC is a faster evolution than the DSM has produced thus far and a more robust generation of hypotheses linking genetics and observed findings to interacting brain domains in mapped brain areas produced by modern neuroscience. This is likely to result in hybrid concepts linking biological mechanisms with psychological findings. Many psychiatrists and psychiatric researchers believe that psychiatric syndromes, DSM5 categories, are the result of dysfunctrional connectivity and not receptor malfunction. Therefore identifying specific circuit dysfunction and relating it to clinically observable phenomena is an important goal of RDoc and is likely the way forward from categorical diagnosis.