Personality disorder, depression and functioning: results from the ODIN study

www.elsevier.com/locate/jad

Journal of Affective Disorders 82 (2004) 277–283

Brief Report

Personality disorder, depression and functioning:

results from the ODIN study

Patricia Caseya,*, Gail Birbeckb, Catherine McDonaghc,Ann Horgand, Chris Dowricke, Odd Dalgardf, Ville Lethineng,

Jose Luis Ayuso-Mateosh, Graham Dunni, Helen Page, Claire Wilkinsonj,Greg Wilkinsonk, Jose Luis Vazquez-Barquerol

The ODIN GroupaMater Misericordiae Hospital, Department of Psychiatry/University College Dublin, Eccles St., Dublin 7, Ireland

bNational Research Agency, The Penthouse, Bracken Court, Bracken Rd., Dublin 18, IrelandcSt. Davnet’s Hospital, Monaghan, Ireland

dTralee General Hospital, Co. Kerry, IrelandeDepartment of Primary Care, University of Liverpool, Liverpool, UK

fUniversity of Oslo, Oslo, NorwaygMental Health Unit, Turku, Finland

hUniversidad Autonoma de Madrid, Madrid, SpainiDeparment of Statistics, University of Manchester, Manchester, UK

jDepartment of General Practice, University of Wales College of Medicine, UKkDepartment of Psychiatry, University of Liverpool, Liverpool, UK

lUniversity Hospital Marques de Valdecilla, Santander, Spain

Received 28 July 2003; received in revised form 7 November 2003; accepted 13 November 2003

Abstract

Background: There is little information of the prevalence of personality disorder (PD) in those with depressive disorder in

community samples; neither is there any data on the impact of PD on service utilisation or outcome in this setting.Methods: A two

stage screening study to identify cases of depressive disorder using SCAN in five European countries. Personality assessed 6

months after the diagnostic interview. Follow-up for 1 year using symptom and social function measures. Results: Personality

disorder is present in 22% of a community sample with depressive disorders but the range varied from 13.7% to 33.3% across

countries. Cluster C formed 43% of the total. Long-term psychotropic drug use was more common in the PD group even after

depression was controlled. Those with PD had higher symptom scores at the outset and, although the PD group was more likely to

be cases at follow-up, this disappearedwhen the depression score was co-varied. Only initial social function predicted outcome at 6

and 12 months. Limitations: The use of a non-treatment seeking population may limit the application of the findings to clinical

populations. Conclusions: PD is common even in a non-treatment seeking population with depressive disorder. It impacts upon

0165-0327/$ - see front matter D 2003 Elsevier B.V. All rights reserved.

doi:10.1016/j.jad.2003.11.009

* Corresponding author. Tel.: +353-1-8032176; fax: +353-1-8309323.

E-mail address: [email protected] (P. Casey).1 Andres Arriaga, Lourdes Aznar, Trygve Borve, Andres Gomez del Barrio, Alfonso de la Calle, Maria Carnicero, Emma del Castillo,

Graham Dunn, Mette Finne, Fiona Ford, Clare Hayes, Andres Herran, Fiona Johnstone, Nicola Jones, Tarja Koffert, Lourdes Laza, Marja Lehtila,

Erin, Michalak, Christine Murphy, Anne Navra, Teija Nummelin, Armando Oviedo, Helen Page, Helena Rasi-Hakala and Britta Sohlman.

P. Casey et al. / Journal of Affective Disorders 82 (2004) 277–283278

outcome at 6 and 12 months but this is related to the initial severity of depressed mood. Social function is the only independent

predictor of outcome and should be assessed separately.

D 2003 Elsevier B.V. All rights reserved.

Keywords: Personality disorder; Social function; Depressive disorders; Community; Outcome

Depressive disorders and personality disorder (PD) 1. Methods

are often co-morbid although the strength of this

association varies with the treatment setting. For

example, in primary care, 25% of those with depres-

sive disorders were co-morbid for personality disorder

(Casey and Tyrer, 1990; Patience et al., 1995) and

among psychiatric out-patient attendees this co-mor-

bidity is even greater (Corruble et al., 1996). There is

agreement that the presence of a personality disorder

has an adverse effect on the outcome of, and GP

service utilization by, those with axis 1 disorders

(Patience et al., 1995; Moran et al., 2001), although

this view has recently been challenged (Mulder, 2002).

Little attention has been directed to those in the

community with depressive disorders and co-morbid

personality disorder and those studies that have incor-

porated evaluation of personality have limited it to the

antisocial category (Jenkins et al., 1997; Kessler et al.,

1994). It is therefore unclear if the adverse effect of

co-morbid axis 1 and axis 2 diagnoses is similar in

community and in clinical settings.

The study reported here is part of a larger two stage

screening study of depressive disorders, the Outcome

of Depression International Network (ODIN). Con-

ducted in five European countries, the overall aim was

to evaluate the prevalence and outcome of depressive

disorders in the general population.

The aim of the present paper is to report the

national trends in the five participating countries of

co-morbid personality and depressive disorders. It

also examines the impact of PD on the severity of

depressive disorders, on social functioning, medica-

tion and service utilization and on functional and

symptomatic outcome.

We tested the hypotheses that depressive disorder

when co-morbid with personality disorder would be

associated with greater symptomatic severity and func-

tional incapacity, and with greater use of the primary

care services and psychotropic medication when com-

pared to those with depressive disorder alone.

The methods for this study have been described in

detail elsewhere (Dowrick et al., 1998) but will be

summarised here for clarity.

1.1. Screening, diagnosis and risk factors

Adults aged between 18 and 64 were selected from

the census register in urban and rural sites in Ireland,

Britain, Norway, Finland and from an urban site only

in Spain. The sample was screened for depressive

disorder using the Beck Depression Inventory (BDI)

(Beck et al., 1961). Those scoring above the cut-off of

13 were then offered a diagnostic interview, using the

Schedule for Clinical Assessment in Neuropsychiatry

(SCAN)(WHO, 1994). The ICD-10 (WHO, 1992)

diagnoses of interest were single and recurrent de-

pressive episodes, bipolar and persistent mood disor-

ders and adjustment disorder with depressive features.

All SCAN cases were re-assessed 6 and 12 months

after the initial diagnostic interview.

Possible risk factors for these disorders were ex-

amined including social supports using the method of

Dalgard et al. (1995) and life events using the list of

life threatening experiences (Brugha et al., 1985).

Health service and medication use was measured

using the Client Service Receipt Inventory (Knapp

and Beecham, 1993).

1.2. Personality assessment

Personality was assessed using the Personality

Assessment Schedule (PAS) (Tyrer and Alexander,

1979). Only those who were SCAN positive for any

depressive disorder were assessed and this took place

at the time of the 2nd SCAN interview since a

sizeable proportion would have recovered by then,

minimising the possibility of contamination by axis 1

symptoms.

Table 1

Personality disorder by country and category

Country N PDa Total nb % PDc CI

Finland 16 80 20 11–28.7

Ireland 4 18 22.2 3–41

Norway 13 95 13.7 6.8–20.6

Spain 7 21 33.3 13–53

Britain 15 88 17 9–24.8

Total 55 302 22 13.9–22.6

a n PD= number with personality disorder.b Total n= total number interviewed.c % PD=% with personality disorder.

Table 2

Demographics by personality disorder

Variable Group PD

present

Total n Significance

Sex Male 20% 95 N/S

Female 23% 207

Age < 45 25% 142 N/S

>45 19% 160

Marital Single 30% 44 N/S

Status Marr/Wid 20% 198

Sep/Div 26% 58

Employment Employed 18% 158 N/S

Status Unemployed 25% 28

Location Urban 24% 170 N/S

Rural 20% 132

P. Casey et al. / Journal of Affective Disorders 82 (2004) 277–283 279

The PAS is a structured interview in which 24

personality traits are rated on a 9-point scale. A

computer programme generates a categorical diagnosis

for ICD-10 (1992). Questions in the schedule are

framed so that constant reference is made to pre-morbid

traits. Behavioural examples, noticeable to those out-

side the person’s immediate circle of friends/family, are

required to confirm the trait abnormality and thesemust

be consistent in a variety of settings prior to the onset of

any axis 1 episode.

1.3. Social function schedule

Social functionwasmeasured using the Social Func-

tioning Schedule (SFS) (Remington and Tyrer, 1979).

The interview takes about 15 min and 12 areas of

functioning are assessed on a visual analogue scale,

covering the previous month and generating a score

from 0 to 100 with a high score indicating impairment.

1.4. Training and quality assurance

All interviewers were trained in the use of the PAS

by one of the authors (PC) who had extensive expe-

rience in its use. This consisted of scoring videotaped

interviews prepared by one of the authors of the

schedule (PT) followed by a refresher course just

before the personality evaluation commenced.

1.5. Statistical analysis

Data was analysed using SPSS for windows (8.0).

Since the vast majority of the patients providing date

(297 out of 302) were initially from the screen

positive sample, sampling weights were not used in

the analyses reported in this paper.

2. Results

2.1. Descriptive data

Three hundred and two people with depressive

disorders were interviewed of whom 55 (22%) had

personality disorder although it is clear from Table 1

that there is wide variation between countries, the

proportion being highest in Spain and lowest in

Britain.

Table 2 shows the demographic breakdown as well

as the employment status of those with and without

personality disorder.

2.2. Symptoms and social functioning

The mean BDI and social functioning scores of

those depressives with and without personality disor-

der as well as their trajectory over the 1-year follow-

up period are shown in Fig. 1.

Only the BDI score at time 1 is significantly

higher for the personality disorder group. Neither

social function nor the BDI score at any other time

point differs between the personality disorder

groups.

2.3. Treatment and outcome

The effect of personality disorder on referral to

psychiatric services at any time during the study period,

as well as antidepressant prescribing and psychotropic

medication use is shown in Tables 3 and 4 and a few

Fig. 1. Box plot of BDI and social functioning scores by personality disorder over time (mean and inter-quartile range).


significant findings emerge; the use of psychotropic

medication at first assessment is significantly higher in

thosewith personality disorder although this disappears

when co-varied for severity of depression. The use of

psychotropic medication at 1-year follow-up is also

significantly higher in the personality-disordered group

and this remains even after co-varying for severity of

depression.

Table 3

Effect of personality disorder on outcome

Outcome PD+N (%) PD-N (%) Crude OR (CI) Adjusted ORa (CI)

Referral to psychiatric services 14 (25.5) 4 (17.4%) 0.62 (0.31–1.23) 1.3 (0.63–2.77)

Any medication at 1st interview 36 (65.5%) 128 (51.8%) 1.76 (0.96–3.2) 1.35 (0.7–2.55)

Any medication at 1 year 23 (65.7%) 107 (72.3%) 0.73 (0.33–1.6) 0.45 (0.19–1.09)

Psychotropics at 1st interview 29 (80.6%) 77 (60.2%) 2.7 (1.12–6.4) 2.48 (0.98–6.27)

Psychotropics at 1 year 20 (87%) 61 (57%) 5.0 (1.4–17.9) 4.7 (1.29–17.25)

Antidepressants at 1st interview 22 (75.9%) 55 (71.4%) 1.25 (0.47–3.3) 0.96 (0.33–2.78)

Antidepressants at 1 year 17 (85%) 47 (77%) 1.69 (0.43–6.6) 0.92 (0.21–4)

Caseness at 6 months 36 (65.5%) 109 (44.5%) 2.36 (1.28–4.35) 1.83 (0.97–3.46)

Caseness at 1 year 24 (51.1%) 87 (39.4%) 1.6 (0.85–3.03) 1.26 (0.65–2.45)

a Co-varying for BDI score at initial interview.


Those with personality disorder were also more

likely to be ‘‘cases’’ at 6-month follow-up but this no

longer pertains when the severity of initial depression

is co-varied. Logistic regression analysis was used to

evaluate the factors influencing the outcome at 6

months and 1 year.

At 6-month follow-up life events, severity of

depression and social functioning at time 1, all

contributed significantly to caseness, but by 1 year

neither life events nor depression severity at time 1

were significant and only social functioning contin-

ued to significantly influence outcome. In view of

the recognised relationship between personality dis-

order and social function the possibility of an

interaction between personality disorder and social

functioning in determining ‘‘caseness’’ at follow-up

was explored but none emerged either at 6 months

(OR 0.79, CI 0.54–1.16) or 1 year follow-up (OR

1.05, CI 0.69–1.61).

Table 4

Logistic regression for caseness at 6 months and 1 year by risk

factors

Variable 6 months 1 year

ORa CIb ORa CIb

Social support 0.76 0.42–1.35 1.2 0.68–2.3

Life eventsz 1 2.18 1.19–3.95 0.87 0.48–1.6

Agez 45 0.72 0.42–1.21 0.77 0.44–1.3

Personality disorder 1.6 0.78–3.2 1 0.49–2.1

Social function (time 1) 1.29 1.07–1.55 1.2 1.1–1.5

BDI score (time 1) 1.05 1.02–1.09 1 1–1.1

a Odds ratio.b 95% confidence intervals.

3. Discussion

There are a number of methodological issues

relating to the study methods that are worth examin-

ing. Firstly, the population under study is one that is

not seeking treatment having been recruited by a two-

stage screening process. The relevance of the findings

to clinical populations is therefore open to question.

The issue of contamination of personality by de-

pressive perspective is one that is also a cause of

concern. By using an interview schedule that con-

stantly refers to the pre-morbid state and by conduct-

ing the interviews at the 6-month follow-up point

when 50% of subjects were no longer SCAN cases,

it was hoped to minimize this problem.

Finally, the sample size is small in some of the

sites, notwithstanding the large number who were

screened. Where sample size is believed to compro-

mise the generalisability, this is stated in the text.

Consideration was given to evaluating personality in

a sample of non-depressed subjects as this would

have provided information on the frequency of

personality disorder in the community and on the

role of personality disorder in the aetiology of

depressive disorders but funding and time constraints

prevented this.

3.1. Descriptive data

Our study is unique in that it is the first to

examine the impact of the totality of personality

disorders on a community sample with depression

although comparison with other studies is, by im-

plication, limited.


Studies of personality disorder in the general

population have found a prevalence of between

5.9% and 13.4% (Samuels et al., 1994; Torgersen

et al., 2001) and among primary care attendees with

depressive illness over 25% have co-morbid person-

ality disorder (Patience et al., 1995; Casey and Tyrer,

1990). Our finding of an overall prevalence of 22%

for co-morbid PD in this study of community

depressives is therefore not unexpected, lying be-

tween the figure obtained for the general population

and primary care attendee. The figure for Spain is

much higher than that of any other country and must

be interpreted with caution in view of the small

sample size and wide confidence intervals. Other

explanations for the variation in prevalence between

countries, and not answerable using the present

methodology, include cultural differences in admit-

ting to abnormal personality traits.

The demographic data is of some interest since we

found no gender, age, urban/rural or employment

status differences. As there have been no previous

studies among those with depressive disorders in the

general population that included all categories of PD,

it is not possible to comment further since studies that

have identified differences have been carried on the

general rather than depressed community samples

(Blazer et al., 1985).

3.2. Symptoms and functioning

Surprisingly, social functioning did not distin-

guish the personality disordered from the non-per-

sonality disordered depressives possibly due to the

different impact personality has on functioning in a

sample from the general population or alternatively

due to the differing social impact that depressive

disorders have on those in a population not seeking

treatment, since social dysfunction is one factor

associated with referral to the specialist services

(Casey et al., 1985). Our results point to the possi-

bility that personality disorder ‘‘behaves’’ differently

with regard to depression in community settings and

this is supported by the finding that speed of

recovery was no different between those with and

without personality disorder, differing from the find-

ings of studies conducted in clinical settings (Pa-

tience et al., 1995; Casey et al., 1996) in which

recovery is slower in the former.

3.3. Treatment and service impact

Our findings that personality disorder did not

increase referral to the psychiatric services differs

from other studies in primary care (Moran et al.,

2001) and again is probably due to the present

sample being one that is not actively seeking

treatment. We have however replicated the findings

of others that greater use of short-term psychotro-

pic medication in those with personality disorder

was dependent on depression severity (Moran et

al., 2001; Rendu et al., 2002) but that long-term

use was independent of depression severity. This

highlights the importance of assessing personality

in those with mood disorders in view of the

hazards of long-term medication use.

3.4. Outcome

Univariate analysis confirmed the findings of

others (Patience et al., 1995) that the short-term

outcome of depression is worse in those with

personality disorder due to the greater severity of

depressed mood in this group. In multivariate anal-

ysis, personality disorder did not emerge as influ-

encing outcome either at 6 months or 1 year, a

finding supporting the results of a recent meta-

analysis (Mulder, 2002). However, initial social

functioning did predict outcome, highlighting the

importance of conducting such an evaluation. The

failure to find an interaction with personality disor-

der demonstrates that in a community population

social function is not a proxy measure for person-

ality disorder.

In conclusion, this study highlights the impor-

tance of personality disorder in relation to several

aspects of depressive disorders, particularly psy-

chotropic medication use. However, social func-

tioning is much more important in determining

outcome and this is independent of personality

disorder.

Acknowledgements

ODIN has received financial support from: the

European Commission Biomed 2 Programme (Con-

tract BMH-4-CT96-1681); English National Health


Service Executive North West Research and Develop-

ment Office (contract RDO/18/31); Spanish F.I.S.

(Exp. No. 96/1798); Welsh Office of Research and

Development (Contract RC092); grants from the

Norwegian Research Council, Council for Mental

Health and Department of Health and Social Welfare;

the Finnish Pensions Institute of Agricultural En-

trepreneurs (Contract 0339); and grants from the

University Central Hospital of Turku.

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Personality disorder, depression and functioning: results from the ODIN study

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