Phenomenology and specificity of
61 Phenomenology and specificity of depressive symptoms
The only symptom clusters (i.e., groups of related symptoms clustered into
“syndromes” according to the criteria established for the PSE) (Wing et al. 1974) that were significantly different between patients with functional major depression and those with poststroke major depression were slowness (SL), which was more frequent in the stroke patients and loss of interest and concentration (IC), which was more frequent in the functional depression group (Fig. 7.1).
The fact that the symptom profiles only differed in 2 of 18 possible categories suggests that major depression following stroke is probably quite similar to the pri-mary depressive disorders (i.e., no brain injury) in the elderly.
Gainotti et al. (1997, 1999) also published studies comparing the phenomenol-ogy of poststroke depression with major depression in patients without brain injury. The diagnosis of poststroke depression was made using the scale devised by Gainotti et al. (1997) entitled the poststroke depression rating scale (PSDS). The
0 10 20 30 40 50 60 70 80 90 100
SD GA AF HM OV SL ED AG NG IR TE LE WO IT SU IC OD Symptom cluster
% of patients with syndrome
Patients with poststroke depression Patients with functional depression
Figure 7.1 Patients with major depression following acute stroke (N 43) were compared to age comparable patients hospitalized for functional primary depression (N 43). The symptom clusters are ”syndromes” derived from the semi-structured interview of the PSE.
SD: simple depression; GA: general anxiety; AF: affective flattening; HM: hypomania; OV:
overactivity; SL: slowness; ED: special features of depression; AG: agitation; NG: self-neglect; IR: ideas of reference; TE: tension; LE: lack of energy; WO: worrying; IT: irritability;
SU: social unease; IC: loss of interest and concentration; and OD: other symptoms of depression. Patients with primary and poststroke depressions showed the same frequency of all syndromes except SL (stroke patients showed a higher frequency) and IC (primary depression patients showed a higher frequency) (reprinted with permission from Lipsey et al. 1986).
PSDS consists of 10 sections examining the following symptoms: (1) depressed mood, (2) guilt feelings, (3) thoughts of death or suicide, (4) vegetative disorders, (5) apathy and loss of interest, (6) anxiety, (7) catastrophic reactions, (8) hyper emotionalism, (9) anhedonia (i.e., inability to enjoy pleasant experiences), and (10) diurnal mood variation. The section on diurnal mood variation is scored2, if there is both an unmotivated cause for depression and prominent increased sever-ity of depression in the early morning. A score of2, on the other hand, represents a clearly motivated cause for depression with the depression worsening during sit-uations that bring out handicaps and disabilities. Inter-rater reliability between a neurologist’s and a psychiatrist’s use of the PSDS was examined in 33 stroke patients who were independently examined on the same day in the morning and early after-noon. Spearman rho correlation coefficients for each of the 10 sections ranged from 0.92 for depressed mood to 0.62 for diurnal mood variation (Gainotti et al. 1997).
Using the PSDS, another group of 120 patients were examined using the PSDS and added to the original 33 (Gainotti et al. 1999). Dividing patients by time since stroke, 58 patients were examined within the first 2 months after stroke, 52 patients were examined between 2 and 4 months poststroke, and 43 were examined more than 4 months poststroke. These patients were compared with 30 patients hospital-ized for major depression without known brain injury (i.e., primary depression).
Statistical analysis of the mean scores obtained on each section of the PSDS showed a significantly higher score for patients with primary major depression compared to patients with poststroke major depression on depressed mood, feelings of guilt, sui-cidal thoughts, and anhedonia, while the patients with poststroke major depression had significantly higher scores on anxiety, catastrophic reactions, hyper emotional-ism, and diurnal mood variations compared to the patients with primary depres-sion. Furthermore, when Gainotti et al. examined time since stroke, there were no statistically significant differences in mean scores on the PSDS on any of the 10 sec-tions among patients who were less than 2 months, 2–4 months, and greater than 4 months poststroke. Validity of the PSDS was examined by correlating scores on the Hamilton depression (Ham-D)rating scale with scores on the PSDS for a few symp-toms including depressed mood, guilt feelings, suicidal thoughts, vegetative dis-orders, anhedonia, and anxiety. Spearman rho scores ranged from 0.41 for guilt feelings to 0.88 for vegetative disorders.
Does the demonstration by Gainotti et al. of differences between patients with primary depression and poststroke depression in a number of symptom areas, indicate that the PSDS constitutes a better way of diagnosing poststroke depres-sion? To answer that question, I believe that each of the findings needs to be con-sidered. First, the increased frequency of symptoms such as catastrophic reactions, hyper emotionalism, emotion lability, anxiety, or diurnal variation among patients with poststroke depression that are not used in the diagnosis of major depressive 62 Poststroke depression
disorder must be shown to be an integral part of the syndrome of poststroke depression. In fact, the existing data on catastrophic reactions (Chapter 37), hyper emotionalism (Chapter 41), and anxiety (Chapter 30) demonstrate that these are comorbid disorders. Anxiety, catastrophic reactions, and emotional lability are all common disorders in patients with poststroke major depression. However, cata-strophic reactions, anxiety, and pathological emotions also occur frequently in patients without poststroke depression. Furthermore, the duration of these disor-ders and the clinical and pathological correlates are almost always different than those of poststroke major depression. Thus, these disorders are comorbid disor-ders rather than integral components of poststroke major depressive disorder.
Similarly, the fact that diurnal variation was scored based on whether the patient attributes their depression to the stroke-related disabilities only indicates that patients with poststroke depression tend to attribute their depression to their impairments regardless of whether or not this is truly the cause. The fact that there were no significant differences between patients with primary depression and poststroke depression in the frequency of vegetative symptoms and apathy (i.e., low energy) suggests similarities between these two kinds of depressive disorder.
The second major finding was that depressed mood, anhedonia, feelings of guilt, and suicidal thoughts had higher mean scores among primary depression com-pared with poststroke depression patients. This finding may have been the result of comparing patients who were hospitalized for endogenous depression with patients who were being treated for stroke not depression. These selection criteria inevitably lead to more severe depressions in the endogenous depression com-pared to the poststroke depression group.
Finally, an assessment of the Gainotti et al. data must address the issue that the PSDS are clearly in conflict with the well-established criteria for the diagnosis of major depression in Diagnostic and Statistical Manual of Mental Disorder-IV Text Revised (DSM-IV-TR: American Psychiatric Association 2000). The addition of symptoms such as catastrophic reactions and hyper emotionalism would clearly change the phenomenology of major depression as we know it. Altering the symp-toms that are widely accepted as criteria for major depression must be validated as defining a specific population of patients with a unique disorder. Validation of this new form of poststroke depressive disorder requires demonstration of a pre-dictable duration of the disorder, specific associated clinical and pathological cor-relates, and responses to treatment that are not found when standard criteria are used. Our data presented here, Spalletta’s data in Chapter 5, and the data of others in Chapter 8 on the course of depression, Chapter 23 on the treatment of poststroke depression, biological markers in Chapter 20, and the role of abnormalities of sero-tonergic function in Chapter 21 on the mechanism of poststroke depression, all suggest similarities rather than differences between endogenous and poststroke 63 Phenomenology and specificity of depressive symptoms
depression. It is possible, of course, that poststroke depression may have different mechanisms, and a different course than primary depression, but these differences have yet to be demonstrated. The large literature on primary depression in the eld-erly (Alexopoulos et al. 1997a, b; Krishnan et al. 1997) has shown that depression in the elderly is frequently associated with vascular ischemia seen as hyperintensi-ties on MRI. These and other findings such as decreased frequency of family his-tory of depression in the elderly (Hickie et al. 1995) suggest more similarities than differences in poststroke and primary major depression. I believe that the majority of current data supports the interpretation that poststroke depression is a form of major depression which is provoked in some patients by injury to strategic areas of the brain and others by social or psychological factors which involve the same final common pathways and pathophysiological changes as primary depression in the elderly. The next section will examine the specificity of symptoms used in the diag-nosis of depressive disorder in patients with acute medical illnesses such as stroke.
Since physical illnesses, such as stroke, may produce symptoms such as fatigue, weight loss, or sleep disturbance which are also used for the diagnosis of depres-sion, we wanted to determine which “depressive” symptoms occurred as com-monly in non-depressed as in depressed patients. Alternatively, we also wanted to determine whether the medical condition might have been masking depressive symptoms that would result in a failure to diagnose depression. It is well known that some types of brain injury can lead to unawareness of deficit (i.e., anosog-nosia) (Starkstein et al. 1993) (see Chapter 36) and a severe physical illness can lead to a denial of illness. This analysis, however, was different than the comparisons shown in Chapter 5 where patients with diagnosed depressions were compared for symptom frequency.
Using a combination of Baltimore plus Iowa patients who were hospitalized with an acute stroke, there were 125 who acknowledged the presence of a depressed mood for most of the time since stroke (no other symptom of depression was required).
They were compared with 270 acute stroke patients without a depressed mood. The group with depressed mood was younger than the group without mood distur-bance (57.4 15 years versus 62.8 13 years, respectively, p 0.0004). They also had more impairment, as shown by their scores on the mini-mental state exam (MMSE) (22 6 versus 24 6, p 0.036) and activities of daily living scale (i.e., Johns Hopkins functioning inventory or JHFI) (7.5 5.4 versus 5.4 4.8, p 0.0001). Otherwise, there were no significant differences in the demographic characteristics or the level of impairment between the depressed and non-depressed groups. In order to examine a spectrum of depressive symptoms and not just the symptoms used in DSM-IV diagnostic criteria, we selected a number of psycholog-ical and vegetative depressive symptoms identified by Davidson and Turnbull (1986) as characteristic of depressive disorder.
64 Poststroke depression
65 Phenomenology and specificity of depressive symptoms
The frequencies of each psychological and autonomic (i.e., vegetative or physio-logical) symptoms of depression were then compared between depressed and non-depressed groups (Table 7.1). All symptoms except social withdrawal were significantly more frequent among patients with a depressed mood than in patients without a depressed mood (p 0.001).
The 125 patients with depressed mood had a significantly greater mean number of autonomic symptoms than the 270 patients without mood disturbance (3.2 1.9 versus 1.2 1.3) (p 0.001). The depressed patients also had significantly more psychological symptoms than the non-depressed patients (4.0 2.9 versus 1.2 1.6) (p 0.001). The frequency distributions for the total number of autonomic and
Table 7.1. Autonomic and psychological symptoms in acute stroke patients with and without depressed mood
Depressed mood Non-depressed mood
(n 125) (n 270)
Symptom N (%) N (%) 2 P value*
Autonomic
Anxiety 46 (37) 22 (8) 49.2 0.0001
Anxious foreboding 42 (34) 21 (8) 39.5 0.0001
Morning depression 81 (65) 19 (7) 147.3 0.0001
Weight loss 47 (39) 40 (15) 25.8 0.0001
Delayed sleep 50 (40) 37 (14) 32.5 0.0001
Subjective anergia 84 (67) 102 (38) 30.1 0.0001
Early awakening 41 (33) 41 (15) 14.0 0.0002
Loss of libido 33 (27) 30 (11) 14.0 0.0002
Psychological
Worrying 80 (64) 52 (19) 75.4 0.0001
Brooding 47 (38) 21 (8) 49.7 0.0001
Loss of interest 47 (38) 6 (2) 88.4 0.0001
Hopelessness 41 (48) 25 (9) 31.7 0.0001
Suicidal plans 55 (44) 3 (1) 125.1 0.0001
Social withdrawal 19 (15) 29 (11) 1.5 0.2146
Self-depreciation 30 (24) 21 (8) 18.6 0.0001
Lack of self-confidence 36 (29) 22 (8) 27.0 0.0001
Simple ideas of reference 40 (32) 40 (15) 14.8 0.0001
Guilty ideas of reference 26 (21) 20 (7) 13.8 0.0002
Pathological guilt 28 (23) 23 (9) 13.7 0.0002
Irritability 54 (43) 35 (13) 42.3 0.0001
*Bonferroni corrected p 0.001.
66 Poststroke depression
psychological symptoms are shown in Fig. 7.2. These bar graphs also show a smooth exponential decline in the percentage of non-depressed patients with psychological or vegetative symptoms of depression. Less than 5% of the non-depressed patients had three or more depressive symptoms. Depressed patients, on the other hand, appeared to have a biphasic distribution of symptoms. There were peaks in the percent of patients who had two symptoms or greater than five symp-toms. This may suggest that there are two groups of depressions that differ in their number of associated psychological and autonomic symptoms.
The adequacy of DSM-IV criteria for major depression in this group of med-ically ill patients was assessed first by determining whether major depression was over diagnosed. There were 79 of the 395 patients who were assigned a DSM-IV
Autonomic symptoms
0 10 20 30 40 50
0 2 5 5
Number of symptoms
% with symptoms
1 3 4
Number of symptoms Psychological symptoms
0 20 40 60
% with symptoms
0 1 2 3 4 5 5
Depressed (n 79) Non-depressed (n 316)
Figure 7.2 The percent of patients hospitalized with acute stroke who acknowledge autonomic (vegetative) symptoms (top panel) depression (see Table 7.1 for list of symptoms).
Patients without depressed mood do acknowledge some vegetative and psychological symptoms of depression but significantly fewer than the depressed mood patients (3.6 2.1 SD versus 1.0 1.1, p 0.001 for autonomic symptoms and 4.1 2.8 SD versus 0.9 1.2, p 0.001 for psychological symptoms). Of the 29 patients with five or more autonomic symptoms, 27 had major and two had minor depression.
diagnosis of major depression. Since vegetative or autonomic symptoms (e.g., sleep disturbance) would be the symptoms expected to occur as a non-specific result of an acute medical illness, we adjusted diagnostic criteria to account for the mean rate (i.e., 1.0) of autonomic symptoms in the non-depressed patients. One extra autonomic or psychological symptom (taken from the list of symptoms in Table 7.1) was required in addition to the symptoms required by DSM-IV (i.e., patients had to have one additional depressive symptom beyond the mini-mum five symptoms required for major depression). This requirement changed the diagnosis from major depression to no major depression in only 3 of 79 patients. Requiring two extra symptoms changed the diagnosis in seven patients.
Thus, the rate of major depression according to standard DSM-IV criteria was 20%. This rate of depression declined by 1% if one additional symptom was required and it declined by 2.5% if two additional symptoms were required. This finding suggests that standard DSM-IV criteria will not substantially over diagnose major depression in patients with acute stroke even though they have some
“depressive” symptoms that may result from acute stroke or hospitalization rather than depression.
Cohen-Cole and Stoudemire (1987) reported that four approaches have been used to assess depression in the physically ill. These approaches are the “inclusive approach” in which depressive diagnostic symptoms are counted regardless of whether they may be related to physical illness (Rifkin et al. 1985), the “etiological approach” in which a symptom is counted only if the diagnostician feels it is not caused by the physical illness (Rapp and Vrana 1989), the “substitutive approach”
of Endicott (1984) in which other psychological symptoms of depression replace the vegetative symptoms and the “exclusive approach” in which symptoms are removed from the diagnostic criteria if they are not found to be more frequent in depressed than non-depressed patients (Bukberg et al. 1984).
We examined the longitudinal course of the specificity of depressive symptoms among patients with depression following stroke compared to non-depressed patients who were examined at 3, 6, 12, or 24 months following stroke. Among 395 patients with acute stroke described in the previous study, 142 patients were fol-lowed up for examination at 3, 6, 12, or 24 months following stroke. The patients who were not included in the follow-up had either died, could not be located or follow-up was not planned. Of 142 patients with follow-up, 60 (42%) reported the presence of a depressed mood (depressed group) while they were in hospital and the remaining 82 patients were non-depressed (Paradiso et al. 1997). There were no significant differences in the background characteristics between the depressed and non-depressed group except that the depressed group was significantly younger (p 0.006) and had a significantly higher frequency of personal history of psychiatric disorder (p 0.04).
67 Phenomenology and specificity of depressive symptoms
68 Poststroke depression
The frequency of psychological and vegetative symptoms in hospital and at each of the follow-up visits is shown in Figs 7.3 and 7.4. Throughout the 2-year follow-up, depressed patients showed a higher frequency both of vegetative and psychological symptoms compared with the non-depressed patients. The only symptoms which were not more frequent in the depressed compared to non-depressed patients were:
weight loss and early awakening at the initial evaluation; weight loss, delayed sleep, and early morning awakening at 3 months; weight loss and early morning awakening at 6 months; weight loss, early morning awakening, anxious foreboding, and loss of libido at 1 year; and weight loss and loss of libido at 2 years (Fig. 7.3). Among the psychological symptoms, the depressed patients had a higher frequency of most psychological symptoms throughout the 2-year follow-up (Fig. 7.4). The only psy-chological symptoms that were not significantly more frequent in the depressed than in the non-depressed group were suicidal plans, simple ideas of reference and pathological guilt at 3 months, pathological guilt at 6 months, pathological guilt, suicidal plans, guilty ideas of reference and irritability at 1 year, and pathological guilt and self-depreciation at 2 years (Fig. 7.4).
We examined the effect of using each of the proposed alternative diagnostic methods for poststroke depression using DSM-IV criteria (Paradiso et al. 1997).
The initial diagnoses were based on the inclusive criteria (i.e., symptoms that the patients acknowledged were included as positive even if there was some suspicion that the symptom may have been related to the physical illness). During the in-hospital evaluation, 27 patients (19%) met DSM-IV diagnostic criteria for major depression. We then modified DSM-IV diagnostic criteria by requiring five or more specific symptoms (i.e., we excluded weight loss and early morning awaken-ing from DSM-IV diagnostic criteria because they were not significantly more fre-quent in the depressed than non-depressed patients). Of 27 patients with major depression, three were excluded. Compared to diagnoses based solely on the existence of five or more specific symptoms for the diagnosis of DSM-IV major depression, diagnoses based on unmodified symptoms (i.e., early awakening and weight loss included) had a specificity of 98% and a sensitivity of 100%.
We then modified DSM-IV criteria to examine the substitutive approach (i.e., all vegetative symptoms were eliminated and the presence of four symptoms plus depressed mood was required for the diagnosis of major depression). Using this approach, none of the original 27 patients with major depression were excluded.
Finally, there were four patients who presented with four or more specific symp-toms of major depression but denied the presence of a depressed mood. These cases may represent “masked” depression.
At 3-month follow-up, use of the exclusive approach, which requires only spe-cific symptoms (i.e., weight loss, insomnia, and suicidal ideation were eliminated) led to one of 12 patients (16%) with major depression being excluded. Using
6-month follow-up
Vegetative depressive symptoms 010203040506070
% of patients
% of patients
010
20
30
40
50
60
70
Autonomic anxiety Anxious foreboding Morning depression Weight loss Sleep disturbance Anergia Early awake Loss libido Autonomic anxiety Anxious foreboding Morning depression Weight loss Sleep disturbance Anergia Early awake Loss libido
Autonomic anxiety Anxious foreboding Morning depression Weight loss Sleep disturbance Anergia Early awake Loss libido
Autonomic anxiety Anxious foreboding Morning depression Weight loss Sleep disturbance Anergia Early awake Loss libido
Depressed Non-depressed p 0.05
% of patients
010
20
30
40
50
60
70
80 2-year follow-up
Autonomic anxiety Anxious foreboding Morning depression Weight loss Sleep disturbance Anergia Early awake Loss libido
In-hospital evaluation 1-year follow-up
010
20
30
40
50
60 3-month follow-up
% of patients
% of patients
010
20
30
40
50
60
70
80 Figure 7.3 The frequency of vegetative symptoms of depression in patients with depressed mood and without depressed mood following stroke. Symptom frequency is shown over the 2-year follow-up. Morning depression (i.e., diurnal mood variation) and anergia were associated with depression throughout the entire 2-year period. Loss of libido was only seen early in the follow-up while early morning awakening was only seen late in the follow-up. These findings suggest changes over time in both the effects of chronic medical illness and the phenomenology of depression following stroke (Data taken from Paradiso et al. 1997).
Psychological depressive symptoms 020406080
100 6-month follow-up
020
40
60
80 In-hospital evaluation
% of patients % of patients
Worrying Hopelessness
Loss of interest Suicidal plan Social withdrawal Lack of confidence Idea of reference
Self-depreciation Pathological guilt
Guilty of reference Irritability
Brooding
Worrying Hopelessness
Loss of interest Suicidal plan Social withdrawal Lack of confidence Idea of reference
Self-depreciation Pathological guilt
Guilty of reference Irritability
Brooding
Worrying Hopelessness
Loss of interest Suicidal plan Social withdrawal Lack of confidence Idea of reference
Self-depreciation Pathological guilt
Guilty of reference Irritability
Brooding Worrying
Hopelessness Loss of interest Suicidal plan Social withdrawal Lack of confidence Idea of reference
Self-depreciation Pathological guilt
Guilty of reference Irritability
Brooding
020
40
60
80 1-year follow-up3-month follow-up
020
40
60
80
% of patients
% of patients
Worrying Hopelessness
Loss of interest Suicidal plan Social withdrawal Lack of confidence Idea of reference
Self-depreciation Pathological guilt
Guilty of reference Irritability
Brooding
020
40
60
80 2-year follow-up
% of patients
Figure 7.4 The frequency of psychological symptoms of depression in patients with depressed mood and without depressed mood following stroke. Symptom frequency is shown over the 2-year follow-up. Most symptoms (i.e., worrying, brooding, loss of interest, hopelessness, social withdrawal, lack of self- confidence, self-depreciation, ideas of reference, and irritability) were more frequent in depressed patients through the 2 years following stroke. Feelings of self-blame (self-depreciation and pathological guilt) were less common after the first year poststroke (Data taken from Paradiso et al. 1997).
diagnoses based on specific symptoms as the gold standard, unmodified DSM-IV criteria had 100% sensitivity and 97% specificity. Using the substitutive approach requiring depression plus four psychological symptoms, none of the 12 patients would have been excluded. There was one patient who had four or more specific symptoms of depression but denied the presence of a depressed mood.
At 6-month follow-up, the exclusive approach (i.e., weight loss and insomnia were excluded) resulted in 3 out of 15 patients no longer meeting the criteria for major depression. Using the specific symptoms as the gold standard, the unmodi-fied DSM-IV criteria (i.e., using unmodiunmodi-fied criteria and not differentiating between depression related to physical-illness-related symptoms) had 100% sensi-tivity and 95% specificity. Using the substitutive approach, none of the 15 patients with major depression would have been excluded. There were two patients who presented with four or more specific symptoms of major depression but denied the presence of depressed mood.
At 1-year follow-up, the exclusive approach (weight loss, difficulty concentrat-ing, and suicidal ideation were excluded) resulted in three out of seven patients no longer meeting diagnostic criteria. Using specific symptom diagnosis as the gold standard, unmodified DSM-IV criteria had 100% sensitivity and 95% specificity.
The substitutive approach resulted in none of the seven patients being excluded.
There were two patients who presented with four or more specific symptoms of major depression but who denied the presence of a depressed mood.
At 2-year follow-up, the exclusive approach (i.e., weight loss was excluded) resulted in 2 out of 16 patients with major depression being excluded. Unmodified DSM-IV criteria had 100% sensitivity and 96% specificity. The substitutive approach excluded none of the 16 patients and one patient who presented with four or more symptoms of major depression denied the presence of depressed mood.
Kathol et al. (1990) concluded that the substitutive approach was the best approach given our current knowledge. However, the inclusive approach had a 100% sensitivity and 95% specificity compared with the exclusive (only specific symptoms) approach. Moreover, our 2-year study of the specificity of depressive symptoms found that three vegetative symptoms (autonomic anxiety, morning depression, and subjective anergia) were significantly more frequent in depressed than non-depressed patients at all time points throughout the 2-year period. The vegetative symptom of loss of libido was no longer significantly more common in depressed than non-depressed patients after 6 months and similarly, self-depreciation was no longer more common after 1 year. In contrast, early morning awakening was more frequent in the depressed group only at 2-year follow-up. Weight loss was the only symptom that was not significantly more frequent in depressed than non-depressed patients over the entire 2-year period. Autonomic symptoms of anxiety, anxious foreboding, and worrying were significantly associated with 71 Phenomenology and specificity of depressive symptoms
depression throughout the entire first 2 years following stroke. In the present study, the sensitivity of unmodified DSM-IV criteria consistently showed a sensi-tivity of 100% and a specificity that ranged from 95% to 98% compared to criteria only using specific symptoms. Thus, one could reasonably conclude that modify-ing DSM-IV criteria because of the existence of an acute medical illness is proba-bly unnecessary.
These findings also suggest that the nature of poststroke depression may be changing over time. Since the symptoms that were specific to depression changed over time, this may reflect an alteration in the underlying etiology of poststroke depression associated with early onset depression compared to the late or chronic poststroke period. Early onset depression was found to be characterized by anxious foreboding, loss of libido, and feelings of guilt which may have been more biolog-ically determined, while symptoms such as early morning awakening and social withdrawal, which were found to be significantly different in depressed compared with non-depressed patients only during the 1- or 2-year follow-up may charac-terize forms of depression that are related to psychosocial or other factors.
Another question we tried to address (Fedoroff et al. 1991) was whether major depression might be under diagnosed because some patients were unable or unwill-ing to acknowledge their depressed mood. To answer this question, we determined how many patients would have met diagnostic criteria for major depression except they had not denied having a depressed mood. In the initial study of 395 patients in-hospital, there were 19 such patients. The background characteristics of these patients, compared to those of the patients who met the standard DSM-IV criteria for major depression (i.e., they acknowledged a depressed mood) are shown in Table 7.2. There were no significant differences in background characteristics between the groups with major depression and major depression without depressed mood. The mean scores for the major depression and no depressed mood groups on the MMSE were 22 6 (SD) and 23 7, respectively, and on the JHFI they were 8 6 (SD) and 8 5, respectively. These scores were not significantly dif-ferent. However, the 77 patients who met all of the criteria for major depression had more severe depressive symptoms as measured by the mean Ham-D score com-pared with patients without a depressed mood (18 7 versus 15 5) (NS). In addition, there was a significantly higher frequency of right hemisphere lesions in the patients with no depressed mood compared to those in the group with major depression (Table 7.2).
Although a number of explanations might be proposed to understand these findings, one explanation is that these19 patients had an inability to recognize their depressed mood as well as other symptoms of depression such as hopelessness or guilt. These patients, therefore, had less severe depressions. This failure to recog-nize depressive symptoms is associated with right hemisphere lesions. Future 72 Poststroke depression
73 Phenomenology and specificity of depressive symptoms
studies may examine the longitudinal course of these patients or their response to treatment to determine whether they are truly masked depressions.
In summary, the phenomenology of major depressive disorder in patients with stroke appears to be similar to that found in patients with primary mood disorders.
In addition, the presence of an acute cerebral infarction does not appear to lead to a significant number of incorrectly diagnosed cases of depression. Perhaps 1–2% of cases may be over diagnosed based on symptoms that result from physical illness.
On the other hand, a small percentage of patients may be under diagnosed based on their failure to acknowledge having a depressed mood. Although these problems of evaluating depressive symptoms in acutely ill-stroke patients may lead to a small proportion of patients being over diagnosed or under diagnosed, the presence of an acute physical illness does not appear to necessitate the development of an entirely new method for diagnosing major depression in this population.
R E F E R E N C ES
Alexopoulos, G. S., Meyers, B. S., Young, R. C., et al. Vascular depression hypothesis. Arch Gen Psychiatr (1997a) 54:915–922.
Alexopoulos, G. S., Meyers, B. S., Young, R. C., et al. Clinically defined vascular depression. Am J Psychiatr (1997b) 154:562–565.
American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorder-DSM-IV-TR. American Psychiatric Association, Washington, 2000.
Table 7.2. Characteristics of acute stroke patients who met all DSM-III criteria for major depression or all DSM-III criteria except depressed mood
Met all criteria except Met all criteria depressed mood
(n 77) (n 19)
Characteristic N % N %
Male 40 52 8 42
Black 28 36 6 32
Married 37 48 10 53
Hollingshead social Class I–III 19 25 6 32
Lesion location
Left hemisphere 27 38 3 18
Right hemisphere* 30 42 13 76
Other (multiple, brain stem, or cerebellar) 15 21 1 6
*The difference between groups was significant (Fisher’s exact p 0.0142).