How should depression be diagnosed in patients with stroke?

For many years, the issue of how to diagnose depression among patients with physical illness has been the focus of numerous publications. CohenCole and Kauffman (1) proposed four methods for diagnosing depression among the physically ill. These included: i) diagnosing depression using only symptoms that were shown to be significantly more frequent in patients with depression plus a specific physical illness compared with patients with this physical illness, but without depression (i.e. specific symptoms method), ii) substituting psychological symptoms for somatic symptoms (i.e. substitutive method), iii) having clinicians make judgments about whether symptoms are due to the physical illness or to depression (i.e. clinical judgment method) and iv) using symptoms for the diagnoses of depression regardless of whether they appear to be related to the physical illness or not (i.e. the inclusive method) (1). In the field of poststroke depression, this debate has taken the form of over diagnosis. For example, House et al. (2) suggested that poststroke depression was being substantially over diagnosed because pathological emotion (i.e. spontaneous crying) was being misinterpreted as depressive disorder (3), while Staub & Bogousslavsky (4) proposed that loss of energy as a diagnostic symptom of poststroke depression was being confused with poststroke fatigue. Because the etiology of psychiatric disorders is largely unknown, our diagnostic nosology has been focused on clinical manifestations, duration of disorders and interference with daily function. Thus, we continue to assess the utility of our current diagnostic system based on studies of reliability and validity of the diagnostic symptoms used to define our categories. As part of this effort, our research groups have examined this issue of the validity of using DSM diagnostic criteria for major depression among patients with stroke (5–7). These studies have demonstrated that almost all of the diagnostic symptoms for major depression following stroke are significantly more common among depressed, compared with non-depressed patients (5, 7). The only symptom that has been found to be of doubtful validity in the diagnosis of poststroke depression is, paradoxically, a psychological symptom of depression, that is feelings of guilt (5, 7). Thus, the phenomenology of depressive disorders in patients with stroke is very similar to the phenomenology described in the symptom criterion of Diagnostic and Statistical Manual (DSM) (8) major depressive disorder among patients without brain injury (9). The study by Cummings et al.(10), in the current issue of Acta Psychiatrica Scandinavica, is a constructive addition to this literature and is the largest and latest study to examine DSM depressive symptoms among 50 (out of 149 stroke patients) with a diagnosis of poststroke major depressive disorder, dysthymia, or depressive disorder not otherwise specified, compared to 97 patients (primarily without brain injury) with a similar mix of depressive disorders, among 745 patients examined in community settings. Despite the mix of diagnostic categories and the fact that 17% of the stroke patients and only 8% of the nonstroke depressive patients had major depression, a factor analysis of 10 depressive symptoms in each group demonstrated no significant differences between poststroke depression and non-brain injury related depression for either psychological or physiological symptoms of depression. The only symptom that was statistically and significantly different among the non-brain injured patients, compared with the poststroke depression patients, was the inability to feel (presumably reflecting anhedonia). Based on the studies which have examined poststroke depressions, compared with non-brain injury depressions or stroke patients without depression, it appears that poststroke depression is phenomenologically similar to depression without brain injury, and no modification or, possibly, only small adjustments, of the DSM-IV criteria is needed for diagnosis. Paradiso et al. (7), in fact, demonstrated that using a semistructured mental status examination applied to DSM-IV criteria for depression due to stroke with major depression like episode done within 2 weeks following stroke, Acta Psychiatr Scand 2010: 121: 401–403 All rights reserved DOI: 10.1111/j.1600-0447.2010. 01569.x 2010 John Wiley & Sons A/S