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PRED I C T ING FURTHER SUIC I DAL BEHAVIOUR IN ATTEMPTED SUI C IDE PATI ENTS
A thes i s presen ted in pa r t i a l ful f i lment of the requi remen t s fo r the degree Doc to r of Phi lo s o phy in Psychology
at Massey Universi ty
Kei th James Pet ri e October , 1 983 .
ABSTRACT
Thi s study exami ned the psycho l o g i c a l determ i nan t s of fut u re s u i c i d a l behaviour and idea t i on i n attempted sui c ide patien t s . The approach taken was to iden t i fy pers ona l i ty variab les tha t i ns u la ted the s u i c i d e a t tempter agains t fu rther a t tempts and sui c i d a l tho ugh t s . Three
spe c i f i c a reas were focused on . F i rs t ly , pas t resea rch has shown a t tempters to be under con s i derable s t ress both befo re thei r a t tem p t and u p to two yea rs afterward s . Sel f es teem was tes ted here as a poten t i a l insu lator aga i ns t s t res s , and in part i c u l a r , l o w sel f esteem as an ind i c a t o r of fut u re su i c id a l behaviour . Sec ond l y , many s tud ies have no ted the int imate rela t ionship between dep ression and s u i c ide . Bec k (1 96 7 ) pos tulated tha t the cogn i t ive variable of hopelessness moderates the rel a t i onsh i p between depres s ion and sui c id e . Wh i l e
hopelessness has been imp l i ca ted i n pas t s tud ies o f sui c id a l i n ten t , the p resen t resea rch tes ted ho pelessness as a p red ic t o r o f s u i c i d a l behaviour and idea t i o n . A fu r ther cogn i t ive variab le , rigid i ty , has been found p reviously to be a character i s t i c o f suic idal i nd iv idual s . Th i s s tudy p red icted rig i d i ty i s m o re a fun c t i o n o f the dep res sed c ond i t ion of a t tempt ers , ra ther than bei ng d i re c t ly i nvolved i n sui c i dal behav iour . Thi rd ly , the fac t that sui c i d a l i nd ividuals lead s o c i a l ly i s o l a ted lives has been no ted by many res e a rc hers . The sui c i d e attempt e r ' s social relationships are general l y unsat i sfyi ng and a maj o r source of inte rpe rsonal fri c t i o n . This s tudy exam i ned the ro l e o f soc ial ski l l s i n the development of sui c id a l behaviour , pred i c t i ng l ow soc ial ski l l would be asso c iated w i th future suic i da l behav i o u r and ideati o n . Overa l l , the research i nvestigated the influence of cogni t ive , social ski l l and self esteem variab les on the development of
s u i c i d a l behavio u r .
A s we l l as the above the o r e t i c a l ques tions , the study a l s o examined the p re d ic t ive val i d i ty of the Zung I nd e x of Poten t i a l Sui c i d e . Thi s scale uses c l inical fac t o rs as opposed to the t rad i t ional
approach to pre d ic t ing sui c idal behaviour .
d emographic
The subj ects we re 6 7 at tempted suic ide pa ti ents adm i t ted to three New Zea l and general hospi ta l s . Eac h compl e ted persona l i ty measu res w i thin two days of the i r admission to ho spi t a l . All sub j e c t s we re con tac ted s i x months after the i r d i s charge and 46 completed a f o l low-up ques t i o nna ire . Thi s que s t i o nna i re measured c u rrent l ev e l of d e p res s i on , sui c idal idea t i on and whe the r any fu rthe r suic ide atte mpts had been mad e .
The resu l t s showed 37% o f a t tempters to hav e mad e at l east one further a t tempt and 17% to have been admi t te d to ho spi ta l for a repea t at temp t . Both low self est eem and high hope l e s sness significantly d i s t i nguished repea t e rs from first time at tempters at admissio n , and those pat i ents making a re peat at tempt over the six month fo l low-up period . Hopel e s sness was signifi cant ly rel a t e d to s u i c i d a l i d e a t i o n o n adm i s s i o n , whi l e self es teem was related to bo t h s u i c i d a l ideation and d e pre s s i on at fo l low-up . Poo r social ski l l s did no t pre d i c t fu t u re d e p res s i o n , sui c idal ideation o r a t t empting . The rel a t ionshi p between d epres s ion and the variab l e s of sui c idal ideation and the n umb e r of p re v io us suic i d e attempt s , was largely explained by hope lessnes s . As pred i c ted, cogni t i ve _rigi d i "Ly w:as-s.i-gnJ..fi-ean t1y-Fe-1atea-t-e --d-e-pre-s-si-on a t admi s s ion but not to suic i d a l behaviour o r idea t io n . The Zung Index
o f Poten t ia l Sui c i d e , wh ile s igni ficantly related to suic i da l idea t i o n and the number o f p rev ious suic ide at temp t s , was a very poo r pred i c to r o f fut u r e suicid�l joeation or behav iour.
The resu l ts sugges t psycho l o g i c a l v a riables o ffer cons i derable poten t i a l over demograph i c fac to rs in asses s i ng sui c i d a l risk . The d ifferent ia l effec t s of ho pelessness and sel f es t eem imply a d i v i s i o n in terms o f long and sho r t term sui c i da l risk i s appropri a te , w i th d i fferent variab l es involved over the two period s . The task fo r fu t u re resear c h i s to iden t i fy the spec i fi c components o f hopelessnes s a nd sel f es t eem as wel l as o ther psycho logical variab les i nvo lved i n sui c i d a l behaviou r .
AC KNOWLEDG EMENTS
I n bri nging thi s project to fru i t i o n there have been many people who have he l pe d along the way . I would l ike to thank my superv isors , Dave C larke and Kerry Chambe rlain , fo r the i r pa t i ent and tho ughtfu l c r i t i c i s m of my research as i t deve loped and was c omp le t ed . The i r sugge s t i o n s have contributed immeasurably to this the s i s . George Sho uksm i th p rov ided valuable depa r tmental suppo rt fo r the res e a rch . I would also l ike to acknowledge a grant from the New Zealand Men tal Hea l th Founda tion (#98 1 R52) whic h he l ped with travel l i ng costs . ·
Thanks go to the a t temp ted sui c id e pat i ents who were involved i n the resea rch , often pa rti c i pat ing i n the sincere ho pe they may hel p o the rs in s imi l ia r desperate s i t uations . Ju l i e Ma inland and John Kavanagh , Soc ia l Wo rkers a t Wa ikato Hospi t a l , together w i t h Jo Ba l lagh and Li z Chambe r l a i n at Hu t t Hos p i ta l , gave valuable as s i s tance i n ga the ri ng pat ient data . The i r hel p i s gra tefu lly acknowledged .
Dick (ever-smi l ing) Bro ok , as we l l as Ken McFarland , gave hel pfu l sugges t ions on data analys i s . Wal t Abe l l , who thinks at 78 but explains at 33 , p rovided i l l umina t i o n on compu t e r p ro c e s si ng of the data .
A spec i a l thanks to my friends fo r ge t t i ng me through this i n only a n i rreparably damaged state. " Honorary K iw i " R i c k Les ch at C SPP San F ranc i s co , t racked down mat e r i a l unava i lable i n N ew Zealand . Mary Jane Rothe ram a t Cal S tate , 1. A . has been throughly suppo r t i v e during tEe who l e proj e c t . Others who have kept a spring i n my s t e p and a s pa rk l e
i n the c o r t e x are ; A l i s ta i r Nicho l son , Jye Kang , Wendon and Iona Hutchins , A l an and Sal ly Merry , Hugh Kininmonth and Ma l c o lm Johnson .
F i na l ly I wo u l d like to ded i c a t e thi s the s i s to Dara lyn , my w i fe , who has wo rked so ha rd and hel ped so much .
Table of C o n tents
C HAPTER ONE : OVERV IE\V . . . • . . . • . . . • . . . . . 1
1 . 1 Inc idence . • . . . . . . . • . . . 1
1 . 2 A t t em p t e r Chara c t e ri s t i c s . . . . . . . . . . . • 3
1 . 3 Repea t a t tempts and suicide . . . 5
1 . 4 Probl ems i n ass e s s i ng sui c i d a l risk . . . ? 1 . 5 The o re t ic a l app roaches to sui c i d e pred i c tion • . . . 11
1 . 6 Improv ing risk pred i c t ion • . . . • . . . • . . . . . . • . . . . • . . . 13 1 . 7 Med i c a l co ntac ts of suicidal ind i vidua l s . . . . • . . . . • • . • . . . 14
1 .8 Summa ry and pro po sal . . . • . . . 1 6 C HAPTER TWO : DEPRESSION AND COGN I TIVE C ORRELATES OF SUI CIDAL BEHAVIOUR • • . . . • . . . • . . . • 18
2 . 1 Depres s io n in a t t empted sui c ides • . . . • . . . • . . . • . . . 19
2 . 2 Depre s s i o n and su i c idal death . . . • . . . • . . . • • . . . 20
2 . 3 Sui c i d e ra t es in psychia t r i c d i s o rders . . . 22
2 . 4 Beck ' s view of depre s s i on . . . • . . . . • . • . . . 24
2 . 5 Hope le s sness and sui c i dal behav i o u r . . . . • . . . 25
2 . 6 Cogni t ive rigid ity in su i c i d a l i nd i v i dua l s . . . .. .29
2 . 7 Summa ry . . . • . . • . . . . . . . 30
C HAPTER THRE E : SOC IAL SKILLS AND SUI C I DAL BEHAV IOUR . • . . . 32
3 . 1 Social isolation and sui c idal behaviour . . . . • . . . • . • 33
3 . 2 S o c i a l ski l l s and sui c i d a l behavi o ur . . . 36
3 . 3 The soc i a l bas i s of suicidal beha v iour . . . 39 CHAPTER FOUR : STRESS AND SUIC IDAL BEHAVIOUR . . . • . . . • . . . 42
4 . 1 S t re s s i n the l ives of attempted sui c ide . . . 42
4 . 2 Personal i ty fac t o rs as modera t o r variables . . . • . . . 44
4 . 3 Self e s teem as a stress insu lato r . . . • . . . 45
4 . 4 Summa ry . . . . . . • . . . . . . . • • • . . . • . . • . . . • • • . . • . . . 4 7 CHAPTER F IVE : SCALES FOR PREDICTING SUIC IDAL BEHAVIOUR . . • • . . • . . . 48
5 . 1 Pre v i o us approaches . • . . . • . • . . . • . . • . . . . • . • . . . • . . . • 48
5 . 2 Sui c i d a l d eath pred i c t io n scales • • . . . • . . . • • . . . • 49
5 . 3 Pred i c t ing furthe r suic idal behav iour i n at t empted sui c ides . . . . 64
5·4 Innov a t i ve approaches . . . • . . • . . . • . • • • • . . . • . . . . • . . . • 70
5 . 5 Summary and proposal • • • . . . • . • . • • . • . . • • • • . . . . • • . • • • . . • • . . . • . 71
C HAPTER S IX : SUMJI1ARY AND HYPOTHESES • • . • . . . • . . . . • . • . . • • . • • • • . . . · · · 73
6 . 1 Theor e t i c a l fllodel . . . • . . . • • . . . • • • . . . • . . . • • • • • • • • . • • . • • . . . . • . 73
6 . 2 Hypotheses • . . . • . • . • . • • • . . • • . • • . . . • . • . . . • . . . • . • • • • . . . . • • . 77
CHAPTER SEVEN : METHOD . • • • • • • • . . . • • • • • • • • . . • • . • . . . • • . • . . • . . • . • • • . . • • . • 79
7 . 1 Sub j e c t s . . . 79
-7�roc e ure . . . 79
7.3 Ins t ruments . . . 81
CHAPTER E IGHT : RESULTS . . . • • • . . . • . . . • . . . . • • . . • . . . 93
8 . 1 Overv iew of the res u l ts . . . • •. . . . • . . . • . • . . . • . . . 93
PART I ; THE ATTEMPTER AT ADMISS ION . . . • . • . . . • . . . • . . . . • . 94
8 . 2 Pa t i e n t ques t i o nnaire rel iab i l i ty and valid i ty . • . . . • . . . 95
8 . 3 Ho pe l e s sness , d e pression and sui c idal behaviour • . . • . . . . • . • . • . . . 97
8 . 4 Pred i c ting sui c i8a l idea t i o n at adm is s i o n . • . . . . . . . • . . . 98
8 . 5 Di s c ri minating fi rs t at t empt ers and repea t e rs • • . • . . . • • . . 103
PART I I ; THE SIX M ONTH FOLLOW-UP . . . . • . . . • • • . . . • . . . • . . . . • . . . 1 05 8 . 6 Pred i c t i ng depression level a t the s i x month fo l low-up • . . . 1 09 8 . 7 Pre d i c t i ng sui c id a l idea t i o n a t the six mon th fo l low-up . . . 1 1 1 8 . 8 Di s c riminating rea t t empters aft e r six months . . . • . . . • . . . 1 1 1 8 . 9 Raw s c o res of repeate rs and non- repea t e rs . . . . • . . . • . • . . . 1 1 5 8 . 1 0 The valid ity of the Zung Index of Po ten tial Sui c id e . . . • . . . 1 1 6 8 . 1 1 Summa ry . . • . . . • • • . . . • . . . • . • . . . 1 2 1 C HAPTER NINE : DISCUSSION • • . . . • . . . • . . . • • . . • . . . 1 2 3 9 . 1 The o re t i ca l imp l i c a t ions . . . • . . . • . • • . . . • . . • . . • . . . . • . • . . • . • • . . 1 23 9 . 2 Limi t a t i ons . . . • . . . • . . . . . . . • . . . • • . • . • . • • . • . . . 1 28 9 . 3 Imp l i c a t ions fo r assessment of a t t empted sui c ides . . . 130 9.4 Imp l i c a t ions fo r fu rthe r res earch . . . • . . . • . . . 1 32 9 . 5 Summ a ry and conc lusi ons . . . • . . . . • . . . • . . . . • . . . • . . . 1 34 APPENDI C ES . . . . . . . • . . . . • . . . • . . . • . . . . . • . . • . . . 1 36 REFERENCES . . . • . . . • • . . • . • . . . • . . . 1 58
LIST OF TABLES
1. Co r re l a t i o n s among variab l e s in pas t stud ies of hope l e s s ne s s , depress i o n and sui c idal intent .
2. Scale fo r ass e s s i ng sui c id e risk i n a t t empted sui c i des
Page
27
( Tuckman and Youngman , 1968). SO
3. Sui c i d e potential scale ( Dean e t a l , 1967).
4 . The su i c id e risk assessm ent scale ( Mo t to , 1982).
5 . Po st a t t empt re l ea s e ass essment scales ( Pall i s , 1983).
6 . The neu ro psychia t r ic ho s p i t a l sui c ide pred i c t i o n sched u l e ( Farb e row and Mac K innon , 1974).
7 . An ins trument fo r evalua t i ng sui c id e potent i a l ( Cohen e t a l , 1966).
8. Naval rec rui t sui c i d e pre d i c tion scal e (Hoiberg and Garfein, 1976).
9. Al pha coe ffici ents for Patient Qu-e stionna ire scal e s.
10.Inte rcorrelations among_measuPes-in-Pa:ti.ent Questionnai re.
52
'55
62
66
68
97
1 1 . Fu l l and pa r tial c o r re l a tions for sui c id a l variables with ho pe lessness and depres s ion , contro l l ing social d es i rabil i ty .
12. Varimax ro tated fac t o r ma t r i x fo r Pa t i ent Qu e s t io nnai re scales .
1 3 . Mul ti ple reg re s s i on equa t i o n pred ic t ing sui c i d a l i d ea t ion .
1 4 . Stepwise s e l e c t i o n of fac t o rs in d i s c riminant func t i o n analys i s fo r c las sify ing repe a t e rs and f i r s t attempters a t adm iss i o n .
1 5 . Stand ard d i s c rim inant fun c t ion coeff i c i ents for the fou r se l ec ted fac t o rs .
1 6 . C lassifica t i on re s u l t s for the d i s c riminant func t io n .
1 7 . C r o s s - tabu l a t i o n of first and repea t a t t empters a t adm ission with non- repe a t e rs and repeat e rs aft e r s i x mon ths .
1 8 . Mul tiple regr e s s i o n equ a t i o n pred ic t ing sui c i d a l idea t i on at fo l low-up .
1 9 . Mul ti p l e regres s i o n equa t i o n pred i c t ing sui c i d a l idea t i o n a t fo l l ow-up .
20. S t e pwise selg_c ti_o_n__ e-f- -fae-to rs- in u:lsc rimi nant func t i o n anal ys i s fo r c lass i fy i ng repeat e rs and non- repea t e rs a t
101
102
105
105
109
110
112
fo l low-up .
2 1 . Standa rd d i s c riminant func t i on fo r the two s e l e c ted fac tors .
2 2 . C lass i fi c a t i o n resu l t s fo r the d i scriminant func t ion .
2 3 . Raw s c o res o f repe a t e rs and non- repeaters a t adm i s s i on and s ix mon th fo l l ow-up .
24 . Cronbach alpha re l iab i l i ty coeffi c i ents for the Zung Index o f Po ten t i a l Su i c i d e subsca l e s .
2 5 . Pea rson corre l a t i ons between the Zung Ind ex o f Po t en t i a l Su i c id e and measu res o f s u i c i d a l idea t ion and behaviour .
26 . Pearson corre l a t i o ns be tween the Emo t iona l S t a t u s i tems o f the Zung IPS and sui c i d a l idea t i o n and behav io u r .
1 13
115
117
118
119
1?0
LIST OF FIGURES
1. Number o f suicides and a t tempted sui c i d es in New Zea l and 1 960-- 1 980 .
2. Rat e of s u i c i d e and a t t empted sui cide by age i n New Zealand fo r 1980.
3 . Numbe r o f repo rted fu rther a t tempts a ft e r s i x mon t h fo l l ow-up .
4. Number o f repeaters fo l low-up .
hospi t a l i sed a f t e r s ix month
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108
