Schizophrenic patients with depression: Psychopathological profiles and relationship with negative symptoms

Schizophrenic Patients With Depression: Psychopathological Profiles and Relationship Negative Symptoms

With

Jean-Pierre Lindenmayer, Sandra Grochowski, and Stanley R. Kay? This study investigates the occurrence of depression and related psychopathological features in chronic schizophrenics and attempts to examine whether depressive symptoms are independent of negative symptoms. We found that 54% of our sample of 240 chronic schizophrenics exhibited moderate to severe depression. independent t tests showed that those high in depression tended to exhibit significantly more positive symptoms as defined by the Positive and Negative Syndrome Scale (PANSS). Those with high depression do not exhibit significantly worse negative symptoms compared with low depression, clearly differentiating depression from negative symptoms. Results and the relationship to a previous factor-analytic study of schizophrenic symptoms are discussed. Copyright

0 1991 by W.B. Saunders

Company

w

ILE PAST and recent investigators have pointed out the frequent occurrence of depression in schizophrenia and its implications for morbidity and mortality,‘.’ many studies have been hindered because of the difficulty in clearly separating depressive symptoms from negative symptoms in schizophrenic patients.3 The availability of newer assessment instruments for positive and negative symptoms has facilitated the exploration of the relationship of the negative syndrome with depression.4-” In a study of young, acute, schizophrenic patients,’ our own group found a high correlation of depressive features with negative symptoms at baseline using an operationalized assessment of psychopathology. However, at the 2-year follow-up, depressive and negative symptoms were no longer related. Similarly, Addington and Addington’ found a high degree of overlap between the measure of negative symptoms and the measures of depression in a sample of hospitalized acute schizophrenics. In contrast, a number of other studies found no significant correlation of negative symptoms with depressive symptoms in schizophrenics.9,“’ Some of these discrepancies are related to the phase (acute inpatients v stable outpatients) of illness and others to methodological shortcomings. The first phase of the present study, which has been described elsewhere,” concerned itself with an extensive factor analysis of the cross-sectional presentation of 240 chronic schizophrenics using the Positive and Negative Syndrome Scale (PANSS).12 Using an orthogonal principal component analysis to identify distinct clusters, we found that four statistically related, but not mutually exclusive orthogonal factors (components), accounted for 52% of the variance of the tota psychopathology. The findings confirmed the presence of independent positive

From the Department of Psychiatry, Albert Einstein College of MedicinelMontefiore Medical Center, Bronx Psychiatric Center, NY. TDeceased. Address reprint requests to Jean-Pierre Lindenmayer, M.D., Schizophrenia Research Unit, lSO0 Waters Place, Bronx, NY 10461. Copyright 0 1991 by W.B. Saunders Company OOIO-440X191/3206-0016$03.00/0 52%

Comprehensive

Psychiatry,

Vol. 32, No. 6 (November/December),

1991: pp 528-533

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WITH DEPRESSION

529

and negative syndromes, which accounted for the main share of variance (36.1%). However, the negative and positive syndromes were, in fact, not sufficient to describe schizophrenia. We found, in addition, a component associated mainly with excitement and impulsivity, and a depression component, which included symptoms of anxiety, guilt feelings, somatic concern, preoccupation, and depression (Table 1). The emergence of a distinct affective component, despite the diagnostic screening out of affective and schizoaffective patients, suggests that this is a bona fide aspect of schizophrenia, and one that receives too little attention from clinicians, researchers, and theoreticians, given the emphasis on positive and negative symptoms over the past several years. The present study was designed, therefore, to further explore the incidence of depression in a large sample of schizophrenic patients and its relationship to negative symptoms and other core features of the illness using a systematic and operationalized cross-sectional assessment of a broad range of psychopathology. METHOD Subjects were 240 schizophrenic inpatients selected from hospital settings in New York City, mainly within a state psychiatric center. All were initially screened for a chart-based diagnosis of schizophrenia and then were independently interviewed by a psychiatrist to ascertain whether they met DSM-III criteria for this diagnosis.Ii Those with major affective illness, schizoaffective disorder, organic brain syndrome, mental retardation, or any additional axis I diagnosis were specifically excluded from the study. This sample, gathered over the course of 7 years, had been recruited for purposes of research and training and included patients in both acute and chronic phases of illness who first provided informed consent. From the total of 240 subjects, 179 were men; ethnically, 106 were black, 60 white, 72 Hispanic, and two Asian. The age range was 18 to 68 years (mean, 33.1 2 10.21[SD]), and the duration since first psychiatric hospitalization was between 1 month and 42years (mean, 10.7 2 8.90). All but two patients were undergoing neuroleptic treatment at the time of study and all were experiencing a significant array of psychotic symptoms. PANSSIJ ratings were performed by consensus of one to three trained psychiatrists immediately after the specified 35. to 40-minute interview. The PANSS provided a standardized method of assessing 30 psychiatric symptoms using operationally defined ‘I-point scales. The sum of seven positive symptoms, such as delusions, hallucinations, and conceptual disorganization, constitutes the positive syndrome score; the sum of seven primary negative symptoms, such as blunted affect, passive/ apathetic social withdrawal, and difficulty in abstract thinking, constitutes a negative syndrome score. The total positive minus the negative score provides a bipolar composite index of the predominance of one syndrome in relation to the other. The remaining 16 items that cannot be definitely classified as positive or negative are summed to yield a general psychopathology score. In addition, since the PANSS incorporates the 18 items from the Brief Psychiatric Rating Scale (BPRS),l’ it can be similarly Table 1. Results of Principal Component Analysis of 30 Symptoms Patients (pre-rotated eigen values > 1)

Component Negative Positive Excited Depressive Cognitive Suspicious/persecutory Stereotyped thinking

for 240 Schizophrenic

Eigen Value

Variance (%)

Cumulative %

7.06 3.74 2.55 2.32 1.56 1.08 1.08

23.61 12.48 8.50 7.73 5.21 3.62 3.59

23.61 36.10 44.59 52.32 57.53 61.15 64.73

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scored to assess the five BPRS factors: anergia, thought disturbance, activation, paranoid belligerence, and depression. Data on the validation and standardization have been described elsewhere.4,16The interrater reliability (Pearson r) on subsets of this sample ranged from 81 to 89 for the component scales.” As previously reported,” the 30 PANSS symptoms were then subjected to principal component analysis using equimax rotation to identify the distinct clusters. This type of analysis yields latent hypothetical variables that are closely tied to the original variables, so that component scores can later be used instead of the original variables without any loss of information. The principal component analysis disclosed seven components with eigen values greater than 1 that could account for 64.7% of the total variance (Table 1)” Of these seven, the first four embraced a substantial set of symptoms (five or more) and had eigen values greater than 2. The clearly distinct and statistically unrelated components included a negative syndrome, a positive syndrome, an excitement syndrome, and a depression syndrome. To further ascertain the validity of our depression component, we examined its relationship with scores from the Hamilton Depression Scale.” Our depression component, consisting of PANSSderived depression, anxiety, guilt, somatic concern, and preoccupation, correlated significantly (r = .62, P I .OOl)with the Hamilton Depression Scale,” which was administered in conjunction with the PANSS on a subset of 28 patients from our sample. There were no significant differences in age, years of illness, education, or PANSS scores between the subset and the full sample of 240 chronic schizophrenics, indicating that our depression component score has construct validity and is clinically meaningful. Using the depression component score (mean, 12.01 2 4.28), we separated patients with low depression (n = 16, depression component 16, scoring - 2 SD below the mean), from those with high depression (n = 20, depression component 2 19, scoring - 2 SD above the mean). To contrast those schizophrenics with a high depression and those with a low depression, independent t tests, two-tailed with alpha set at .05, were performed to test differences between the means of those with a high depression component and patients with a low depression component.

RESULTS

As defined by the depression component score, 5% of our 240 chronic schizophrenics showed severe depression (depression component L 19), 52% evidenced a mild to moderate degree of depression (depression component range, 11 to 18), and 41% reported a minimal or no degree of depression (depression component < 11). Examining patients with high and low depression components using independent t tests, we found that schizophrenics with a high depression component score exhibited significantly greater positive syndrome features (t = 3.67, P I .OOl) (Table 2). Those who scored high in depression did not show a significant difference in negative syndrome features as compared to those with a low depression component score. The positive syndrome association with depression was further supported by significantly higher mean ratings of delusions (t = 3.87 P 5 .OOl), hallucinations conceptual disorder (t = 2.66, P I .Ol), and suspiciousness (t = 3.11, P I .005, (t = 2.66 P s .Ol) in the high depression group. The BPRS-defined thought disturbance factor, extracted from the PANSS rating, was also significantly higher among the depressed group, supporting the association of depression with florid psychopathology. Among the individual negative symptoms, only stereotyped thinking was significantly different between the high and low depression groups; those with a high depression component score tended to exhibit greater amounts of stereotyped thinking (t = 3.37, P I .005). Age and years of illness did not differ in regard to the amount of observer-rated depression.

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Table 2. Comparison

531

of Chronic Schizophrenic Patients With High Versus Low Depression Components (N = 240)

Continuous Variable

Age Years ill BPRS Anergia Activation Thought disturbance Positive Syndrome (PAN%) Delusions Hallucinations Conceptual disorganization Excitement Grandiosity Suspiciousness Hostility Negative Syndrome (PANSS) Blunted affect Emotional withdrawal Poor rapport Passive/apathetic social withdrawal Abstract thinking Poverty of thought Stereotyped thinking

Alpha set

at .05. *P I

.Ol;

tP

I

,005: SP

I

Low Depression (n = 16)

High Depression (n = 20)

Mean

(SD)

Mean

(SD)

31.13 7.94

(9.47) (8.60)

31.50 10.35

(7.92) (7.02)

0.13 0.93

8.79 4.29 8.21

(2.08) (1.73) (3.49)

11.70 7.85 13.55

(3.61) (2.32) (4.08)

2.97* 4.87% 3.97s

14.94 2.13 1.88 2.63 1.81 2.06 2.31 2.00

(5.67) (1.46) (1.63) (1.20) (1.22) (1.48) (1.01) (1.32)

21.80 4.00 3.40 3.90 2.40 2.70 3.30 2.10

(5.50) (1.38) (1.31) (1.59) (1.23) (1.75) (1.17) (1.07)

3.67$ 3.87$ 3.11t 2.66* 1.43 1.16 2.66* 0.25

19.63 3.13 2.81 2.87 2.50 3.44 2.87 2.19

(7.84) (1.03) (1.17) (1.60) (1.23) (1.46) (1.89) (1.42)

23.80 3.45 3.60 2.65 3.30 4.35 2.85 3.60

(6.89) (1.28) (1.27) (1.50) (1.26) (1.42) (1.63) (1.10)

1.70 0.83 1.91 0.41 1.84 1.89 0.03 3.37t

t

.OOl.

DISCUSSION

This group of chronic schizophrenics exhibited a fairly high incidence of depression, attesting to its importance as a syndromal part of schizophrenic psychopathology. Similarly, Owens and Johnston,” in a diagnostically more heterogenous sample, reported that 35% of schizophrenics are clinically depressed to a mild or moderate degree. These investigators reviewed other studies and found a range of depression reported from 22% to 59.7%; the higher figure associated with inpatient samples, while studies performed on outpatients reported fewer patients with depression. However, the assessment of depression in these studies is quite variable. The fact that the present sample is also an inpatient sample may account in part for the relatively high incidence of patients exhibiting at least a mild to moderate degree of depression. A potential contamination of the results by extrapyramidally induced akinesia is possible given the association of depression with the BPRS-defined anergia factor; however, this contamination may be negotiable, since the anergia factor includes only motor retardation as a symptom affected by psychopharmacological therapy. Patients high in depression tended to exhibit greater amounts of positive symptoms, particularly in the area of delusions, hallucinations, and conceptual disorganization. It appears that in this subgroup of depressed schizophrenics, the presentation is more a floridly psychotic one, despite the fact that patients with schizoaffective disorder have been excluded. This same group of high depression

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AND KAY

patients exhibits relatively equal amounts of negative symptoms when compared with those with low depression. Clearly, depressive symptoms can be differentiated from negative symptoms in this sample of chronic schizophrenics as demonstrated in the post-acute phase of our previous study.’ This finding also argues against the interpretation that depressed patients are necessarily more deficit-ridden, since our high depression schizophrenics do not show significant association with negative symptoms. This finding is consistent with the studies of Pogue-Geile and Harrow’ and others.‘9-2’ High depression schizophrenics who show more positive symptoms may in fact have more overall affective capacities, allowing them to express depression, compared with a low depression group, which may have a more restricted affect. This interpretation is supported by the results of our factor-analytic study” regarding the interrelationship of positive and depressive components. Based on this study, we argue that patients with a high degree of positive and depression symptoms may correspond to the JSraeplinian subtype of paranoid schizophrenia,” a subtype viewed as having a higher level of functioning and as being cognitively more intact compared with other schizophrenic subtypes. Zigler and Glick23 also link paranoid schizophrenia and depression, arguing that projection is an important defense mechanism against depression and that both sets of psychopathological syndromes can be expected to occur together at certain stages during the course of paranoid schizophrenia. The importance of including syndromal assessments other than positive and negative syndromes in the analysis of schizophrenic psychopathology, in particular the assessment of depression, is thus reinforced by the present study. The presence of depression may have important implications as to the course and treatment of these patients. ACKNOWLEDGMENT The authors wish to acknowledge the participants in various phases of the study, including the work of Lewis A. Opler, M.D., Ph.D., Abraham Fizbein, M.D., and Lisa M. Murrill, M.A.

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