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COGNITIVE PROFILE OF FIRST DEGREE RELATIVES OF PATIENTS WITH SCHIZOPHRENIA

Sreelatha.P1Penzil Pinto2

1Asst.Prof.MJV Medical College and Research Hospital Banglore, 2Professor, Father Muller Medical Medical College Manglore.

 

 

ABSTRACT

BACKGROUND: *Schizophrenia is a clinical syndrome of variable psychopathology that involves cognition, emotion, perception and other aspects of behavior. There is compelling evidence, to prove that cognitive deficits are also present in the first-degree relatives of patients with schizophrenia. This study sets to evaluate the extent of the cognitive deficits in the relatives of patients with schizophrenia. degree relatives of patients with schizophrenia and 30 normal controls, matched for age, gender, education and socio-economic status. Tools used were SMMSE, BCRS, TMT-B, and DSS

MATERIALS AND METHODS

The objective of the study was to assess the cognitive dysfunction in first degree relatives of patients with schizophrenia and to compare the cognitive dysfunctions between the relatives of patients with schizophrenia and healthy controls. This is across-sectional study. Subjects for the study (cases) were a consecutive sample of 30 first-degree relatives of patients who have been diagnosed to have Schizophrenia from the in-patient and outpatient facility of Father Muller Medical College, Mangalore (Karnataka). 30 Controls for the study were the first-degree relatives of patients attending the medical outpatient facility of Father Muller Medical College who do not have a family history of Psychiatric illness. Controls were matched for age, gender andeducation. An informed consentwas obtained from those who were willing to participate inthe study after explaining the nature of study. Initialcontact was made in the hospital wards and outpatient facility and suitable subjects satisfying the inclusion and exclusion criteria were identified.

 

RESULTS: Relatives performed poorly in TMT-B and DSS and made more number of errors in both tests, which was statistically highly significant. Relatives also had very highly significant cognitive dysfunctions in the concentration, recent memory and past memory domains of BCRS as well as the registration, attention and recall domains of SMMSE.

KEY WORDS:Cognition,first-degree,family,schizophrenia

 

INTRODUCTION

Schizophrenia is a clinical syndrome that manifests with diverse

symptomsinvolving thought,emotion, perception and other aspects of behavior. It also is to variable degree is accompanied by cognitive impairment.[1]

Though it has been suggested that some of these cognitive deficits fluctuate with psychopathology, while others are relatively stable[2] it is generally agreed thatcognitiveimpairment is independent of clinical symptoms, antipsychotic medication and course of illness.

Cognitive measures have been studied in patients with schizophrenia and their relatives[3]. Cognitive impairments are found across most domains like attention/vigilance, working memory, verbal fluency, execution functions and verbal memory.[4]

One of the primary goals of research on schizophrenia is the identification of vulnerability factors related to increased risk for developing this disorder.In fact the risk of developing schizophrenia is directly associated with the degree of relatedness to an affected individual.[5]

Several variables are under scanner as potential vulnerability markers including soft neurological signs, minor physical anomalies, evoked potentials and cognitive measures.[6] Recent research is increasingly involving populations other than those with schizophrenia itself, including siblings or relatives of patients with schizophrenia, healthy volunteers, and subjects who are prodromal for schizophrenia in search to identify markers of the illness. Moreover studies of relatives are not confounded by neuroleptic treatment, chronic hospitalization and psychopathology.

A number of different studies[7],[8],[9],[10]have reported deficits in sustained attention, episodic memory, executive functions, disturbances in abstraction, verbal memory, working memory, psychomotor speed, among first-degree relatives of individuals with schizophrenia.[11],[12],[13]on the other hand no cognitive impairment have also been reported.[14]

The analyses of all these studies suggest that relatives of individuals with schizophrenia show impairment in multiple cognitive domains. Much research on cognitive dysfunction in relatives has been done in developed countries.

No extensive quantitative review of literature on cognitive test performance in relatives of schizophrenic patients exists in Indian studies. This study attempts to evaluate the deficits in different cognitive domains in first- degree relatives (parents, siblings, and children) of patients with schizophrenia and their relation to demographic and clinical variables.

 

MATERIALS AND METHODS

The objective of the study was to assess the cognitive dysfunction in first degree relatives of patients with schizophrenia and to compare the cognitive dysfunctions between the relatives of patients with schizophrenia and healthy controls. This is across-sectional study.

Subjects for the study (cases) were a consecutive sample of 30 first-degree relatives of patients who have been diagnosed to have Schizophrenia from the in-patient and outpatient facility of Father Muller Medical College, Mangalore (Karnataka). 30 Controls for the study were the first-degree relatives of patients attending the medical outpatient facility of Father Muller Medical College who do not have a family history of Psychiatric illness. Controls were matched for age, gender and education. An informed consent was obtained from those who were willing to participate in the study after explaining the nature of study. Initial contact was made in the hospital wards and outpatient facility and suitable subjects satisfying the inclusion and exclusion criteria were identified.

Psychiatric evaluation of the subject was done by detailed clinical interview, corroborated with other family members and mental status examination. Diagnosis of schizophrenia was based on ICD-10 diagnostic criteria.

Tools for Assessment:

  1. Semi structured Performa specially designed for the study to collect details of Socio-demographic and clinical variables.
  2. Standardized Mini-Mental State Examination (SMMSE)
  3. Brief Cognitive Rating Scale (BCRS)
  4. Digit Symbol Substitution Test (DSST)
  5.  Trail Making Test – Part B (TMT-B)

cases and controls  areof age group of 18-55 yrs ,who finished their primary school education were included in the study. Patients having any psychiatric disorders, dementia, alcohol and drug abuse and patients with multiple chronic diseases causing cognitive impairment like neurodegenerative diseases, thyroid and adrenal disorders, renal disorders, cancer and stroke were excluded from the study. Controls with a first degree relative diagnosed with a psychotic disorder were excluded from study. This study was conducted from July 2006 to April 2008.

 

RESULTS

Table -1 shows the socio-demographic variables of cases in comparison with the control group. There is no significant difference between the case and control in the parameters of age,gender, marital status, education, occupation.

No

 

 

Cases (n=30)

Control(n=30)

1

Education

Secondary

46.7%

46.7%

Higher Secondary

30%

26.7%.

Graduate

23.3%

26.6%

2

Gender

Male

66.7%(20)

66.7%(20)

Female

33.3%(10)

33.3(10)

3

Domicile

Urban

63.3%

40

Semi Urban

30

50

Rural

6.7%

10

4

Marital Status

Married

93.3%

96.7%

Unmarried

6.3%

3.3%

5

Religion

Hindu

33

36.7%

Muslim

36.7%

36.7%

Others

60.01%

26.7%

6

Family Structure

Nuclear

 

 

Joint

 

 

7

Income

2500

3.3

3.3

2500-5000

20

20

5000-10,000

56.7

56.7%

>10,000

20.01

20.01%

8

Occupation

Executives

3.3%

3.3%

Business

36.7%

36.7%

Industry

26.7%

30%

Others

30

30%

Table-1

 

Standardized mini-mental status examination:

 

Group

Std. Deviation

t test

Orientation

Cases

.740

t(58) = 2.114, p=0.039, Sig

Control

.596

Registration

Cases

.450

t(58) = 3.247, p=0.002, HS

Control

.000

Attention

Cases

.759

t(58) = 7.703, p=0.000, HS

Control

.568

Recall

Cases

.254

t(58) = 6.537, p=0.000, HS

Control

.466

Language

Cases

1.278

t(58) = 1.000, p=0.321, NS

Control

.000

Construction

Cases

.504

t(58) = 2.316, p=0.024, Sig

Control

.379

Total Score SMMSE

Cases

1.903

t(58) = 7.592, p=0.000, HS

Control

1.129

Table-2

SMMSE scores indicated in table-2 shows that there were statistically significant differences between case and control, these differences were circumscribed to domains of attention, registration and recall,orientation and construction.

 

 

Brief cognitive rating scale

 

Group

Mean

Std. Deviation

 

Concentration

Cases

2.17

.461

t(58) = 6.185, p=000,

Control

1.40

.498

Recent memory

Cases

1.77

.430

t(58) = 4.802, p=000,

Control

1.23

.430

Past memory

Cases

1.53

.507

t(58) = 5.757, p=000,

Control

1.00

.000

Orientation

Cases

1.20

.484

t(58) = 2.262, p=0.027,

Control

1.00

.000

Functioning Self Care

Cases

1.10

.305

t(58) = 1.795, p=0.078,

Control

1.00

.000

Total Score BCRS

Cases

1.553

.2813

t(58) = 7.503, p=000,

Control

1.127

.1377

Table-3

 

Results pointed towards the presence of significant cognitive impairment in the case group as compared to the controlling BCRS as depicted in table-3

 

 

Trail making test – Part B (Time taken in sec):

 

Group

Mean

Std. Deviation

 

TMTT (in Sec)

Cases

247.83

56.868

t(58) = 9.023, p=0.000,

Control

145.33

25.255

Table-4

cases as compared to controls took more time  to complete the trail making test as shown in table-4

Trail making test part – B (no of errors):

 

Group

Mean

Std. Deviation

 

TMTE

Cases

6.17

1.085

t(58) = 17.606, p=0.000,

Control

1.67

.884

Table-5

In trail making test, the mean value of number of errors made by the cases was 6.17 with standard deviation of 1.085, while that in control was 1.67 and 0.884 respectively. The number of errors had an adverse impact in the total time taken to complete the test.

Digit symbol substitution test (time taken in seconds):

 

Group

Mean

Std. Deviation

 

DSST (in Sec)

Cases

468.20

77.006

t(58) = 10.484, p=0.000,

Control

283.00

58.584

Table-6

Digit Symbol Substitution Test (No. of errors)

 

Group

Mean

Std. Deviation

 

DSSE

Cases

7.07

1.507

t(58) = 13.945, p=0.000,

Control

1.67

1.066

       Table-7

As indicated in table-6&7 there was highly significant difference in the mean value of time taken to complete the DSST test for both controls as well as cases. Significant differences were noted in both cases and controls in errors made on DSST (P=0.036 in cases).

DISCUSSION

The current study has addressed the cognitive functions in first degree relatives matched against controls with respect to age, gender, education .

The study revealed that there is statistically significant cognitive impairment in first-degree relatives compared with controls.

The mean age in the present study was 41 for controls and 40.97 yrs for cases. Hence, findings of impaired cognitive functions are not confounded by extremes of age. To minimize possible confounding effects of age on neurocognitive variables, subjects were included in the study only if their age ranged from 18-55 yrs. Previous studies have shown cognitive deficits to be present in children of patients with schizophrenia also who were not included in this study.[15]

Majority of subjects in this study were males (66.7%). However, this was at odds with the female preponderance seen in certain other studies, females having performed poorly compared to males.[16]All participants in this study have completed their secondary school education. Previousstudies showed that higher education was associated with better performance in circumscribed cognitive functions. However, this study does not show any significant correlation between education and cognitive measures in cases. Earlier studies have also assessed the IQ of the subjects at the time of intake, which was not done in the current study.

Income has statistically significant impact on cognitive performance in both cases and controls in time taken to finish DSST test, lower income group having an impact on cognitive performance in both cases and controls.

Mini-Mental Status Examination developed by Folste in has widely been used as a measure of cognitive function and had proven to be a reliable and valid indicator of cognitive functions. In this study total mean score obtained by cases has 24.97 and a control is 28.03, a cut off score of less than 24 indicative of cognitive impairment. However highly significant differences have been obtained in individual domains of registration, attention and recall in cases when compared to the controls.

This study has applied BCRS, which has proved successful with results showing significant impairment in the domains of concentration, recent memory and past memory.

In the earlier studies, battery of neuropsychological tests was performed including Stroop Color Word Test (SCWT), Wisconsin Card Sorting Test (WCST). Continuous Performance Tasks, Tower of London test (TOL). These tests seem to have tapped the circumscribed and subtle cognitive impairments, which are much more likely to occur in the relatives of patients with Schizophrenia. To overcome this drawback current study employed two domain specific tests, TMT-B and DSST to assess cognitive function,TMT-B, a test of attention, visual scanning, sequential abilities and executive function revealed very highly significant difference between the cases and control groups. Cases also made more errors than the controls. These findings are consistent with results of previous studies.

DSST, a timed test of attention, psychomotor performance and perceptual organization was significantly affected in the cases as compared to the control group. Results show that TMTT, DSST measures were significantly impaired in the parent group. This result highlights a very important finding, as the parents have crossed the age at risk to develop schizophrenia. It can be concluded therefore that cognitive deficiencies are not solely predictive of later illness, but also exist in relatives that will never be affected.

First-degree relatives of individual with schizophrenia have an increased risk for development of schizotypal personality disorder / symptoms, this might in turn influence the cognitive functioning in this group. In this study, the psychopathology of all participants has been screened in a clinical interview, but in depth analysis, using any of the available assessment tools has not been done. Therefore, it cannot be predicted that any undetected subtle psychopathology could have affected the cognitive functioning.

The current study is a cross-sectional study of the cognitive measure, which cannot analyze the stability of the cognitive deficits measure. Therefore, longitudinal studies assessing cognitive deficits are recommended.

Several previous studies have often combined more than one class of relative in their first-degree sample.[17],[18],[19],[20] Classes of relatives differ on several factors, such as age, genes and environmental insults that could influence their neuropsychological performance. This study has investigated the presence of cognitive deficits in the first-degree relatives but combining multiple relative classes may cloud attempts to detect genetic liability to schizophrenia. Previous studies have compared the cognitive deficits in relatives, controls with patients with schizophrenia, cognitive deficits in relatives were found to be intermediate between relatives with higher deficits and controls. This study could not assess the severity of deficits in relatives in relation to the deficits found in the affected probe and. This study has used cognitive measures that have shown statistically significant impairment. This is strongly correlated with the earlier studies, which have found deficits pronounced in the domains of verbal memory, executive functioning and attention.[21],[22],[23]

CONCLUSION

The study has concluded that cognitive dysfunctions are present in the first-degree relatives of patients with schizophrenia. Deficits were significant in the parent group who have crossed the at risk age for developing schizophrenia, implying that cognitive deficits are present in the relatives of patients with schizophrenia and are independent of their risk of later developing schizophrenia.

REFERENCES

1)Reichenberg.A. The assessment of neuropsychological

Functioning in schizophrenia.Dialogues ClinNeurosci. 2010;12:383-392.

2) Brewer.W.J,  Wood.S.J,  Phillips.L.J,  Francey.S.M,  Pantelis.C,Yung.A.R,et al.Generalized andSpecific Cognitive Performance in Clinical High-Risk Cohorts: AReview HighlightingPotential Vulnerability Markers for Psychosis. Schizophrenia Bulletin 2006;vol. 32 no. 3 pp. 538–555, 2006

3)Thompson JL, Watson JR, Steinhauer SR, et al. Indicators of genetic liability to schizophrenia : a sibling study of neuropsychological performance. Schizophrenia Bulletin 2005; 31(1): 85-96.

4)Wilk CM, Gold JM, McMohan RP. No, it is not possible to be schizophrenic yet neuropsychologically normal. Neuropsychology 2005; 19(6): 778-786.

5) Gottesman II. Schizophrenia Genesis: The origin of madness. New York, NY: Freeman; 1991.

6)Solanki.R.K, Swami.M.K, Singh.P,Gupta.S.Identification ofVulnerability among First-degree Relatives of Patients with Schizophrenia. East Asian Arch Psychiatry.2012;22:118-25

7)Delewalk Z, Barch DM, Fisher JL, Thomeson ES, Hanewinkel MJ, Thompson PA, Csernansky JG. Factors mediating cognitive deficits and psychopathology among siblings of individuals with schizophrenia. Schizophr Bull. 2006; 32 (3): 525-537.

8) Chen WJ, Liu SK,Chang CJ, Lien YJ, Chang YH, Hwu HG. Sustained attention deficit and schizotypal personality features in non psychotic relatives of schizophrenic patients. Am J. Psychiatry .1998; 155: 1214-1220.

9)Liu Z, Zhao J, Tam WCC.Attention and executive function impairments in unaffected siblings of patients with schizophrenia. Hong Kong J Psychiatry. 2003; 13 (2): 8-11.

10) Byrne M, Hodges A, Grant E, Owens C, Johnstone EC. Neuropsychological assessment of young people at high genetic risk for developing schizophrenia compared with controls:preliminary findings of the Edinburgh High Risk Study. Psychol Med. 1999;29:1161–1173

11) Egan MF, Goldberg TE, Gscheidle T, Weirich M, Bigelow LB, Weinberger DR. Relative risk of attention deficits in siblings of patients with schizophrenia. Am J Psychiatry. 2000; 157: 1309-1316.

12) Klemm S, Schmidt B, Knappe S, Blanz B. Impaired working speed and executive functions as frontal lobe dysfunctions in young first-degree relatives of schizophrenic patients. EurChidlAdolesc Psychiatry .2006; 15: 400-408.

13) Faraone SV, Seidman LJ, Kremen WS, Toomey R. Pepple JR, Tsuang MT. Neuropsychological functioning among the nonpsychotic relatives of schizophrenic patients: the effect of genetic loading. Biol Psychiatry. 2000; 48: 120-126.

14)Stratta P,Daneluzzo E, Mattei P,Bustini M, Casacchia M, Rossi A. No deficitin Wisconsin Card Sorting Test performance of schizophrenic patients first-degree relatives. Schizophr Res 1997;26:147–151.

15) Cannon, Tyrone .D, Bearden, Carrie E, Hollister, Megginson.J.et al.

Childhood cognitive functioningin schizophrenia patients and their unaffected siblings: Aprospective cohort study. Schizophrenia Bulletin, Vol 26(2), 2000, 379-393

16)Faraone.S.V,Seidman.L.J,Kremen.W.S,Toomey.R,Pepple.J.R,Tsuang.M.T.Neuropsychologicfunctioning among the nonpsychotic relatives of schizophrenic patients: the effect of genetic loading. Biological Psychiatry,Vol48(2).2000,120-126

17)Thompson JL, Watson JR, Steinhauer SR, et al. Indicators of genetic liability to schizophrenia : a sibling study of neuropsychological performance. Schizophrenia Bulletin 2005; 31(1): 85-96.

18)Mirsky AF, Yardley SL, Jones BP, Walsh D, Kendler KS. Analysis of the Attention Deficit in Schizophrenia: A study of patients and their relatives in Ireland, J. Psychiat. Res. 1995, Vol. 29, No.1, 23-42.

19) McIntosh AM, Harrison LK, Forrester K, Laurie SM, Johnstone EC. Neuropsychological impairments in people with schizophrenia or bipolar disorder and their unaffected relative. British Journal of Psychiatry 2005; 186: 276-385.

20) Trandafir A, Meary A, Schurhoff F, Leboyer M, Szoke A. Memory tests in first-degree adult relatives of schizophrenic patients: a meta analysis. Schizophr Res. 2006; 81 (2-3): 217-226.

21) MacDonald AW, Pogue – Geile MF, Johnson MK, Carter CS. A specific deficit in contest processing in the unaffected siblings of patients with schizophrenia. Arch Gen Psychiatry. 2003; 60: 57-65.

22) Tsuang HC, Lin SH, Liu SK, Hsieh MH, Huang TJ, Liu CM, Hwu HG, Chen WJ. More severe sustained attention deficits in nonpsychotic sibling of multiplex schizophrenia families than in those of simplex ones. Schizophrenia Research .2006 Oct; 87 (1-3): 172-80.

23)Conklin HM, Curtis CE, Katsanis J, Lacono WG. Verbal working memory impairment in schizophrenia patients and their first-degree relatives: Evidence from the digit span task. Am J Psychiatry. 2000; 157: 275-277.