PowerPoint-esitys

1
LONGITUDINAL STUDY OF TEMPERAMENT IN INDIVIDUALS
WITH PSYCHOTIC DISORDERS AND HEALTHY CONTROLS
Jouko Miettunen (1), Eka Roivainen (2), Juha
Veijola (1,3), Antti Alaräisänen (1), Matti
Isohanni (1), Erika Jääskeläinen (1) 1)
Department of Psychiatry, Oulu University and
Oulu University Hospital, Oulu, Finland, 2) Oulu
Deaconess Institute, Oulu, Finland, 3) Institute
of Health Sciences, University of Oulu, Oulu,
Finland
Objective The Temperament and Character
Inventory (TCI) developed by Cloninger is used to
measure novelty seeking (NS), harm avoidance
(HA), reward dependence RD), and persistence (P).
Temperament is a possible endophenotype for
psychiatric disorders and may also relate e.g.
treatment adherence, and social and clinical
outcome of the illness. There are not many
longitudinal studies on temperament, especially
stability of temperament among individuals with
psychosis is unknown. We evaluated stability of
temperament and infrequency in answering in
individuals with psychotic disorders and healthy
control subjects.
Methods As part of the 31-year follow-up survey
of the prospective population based Northern
Finland 1966 Birth Cohort, the temperament part
(107 items) of TCI and an Infrequency Scale (12
items indicating random or fake answers, maximum
12 points) were collected from a large sample of
individuals (n4943). A case-control subsample of
psychotic individuals (n28), with onset age
before the first follow-up (mean 25.0 years), and
healthy controls (n116) were given these scales
again in a second follow-up at the age of 43.

• Results
• A high rate of invalid responding was observed
  in psychotic individuals at age 43 years. When
  taking into account both follow-ups, 39 had
  either too many missing or infrequent answers
  corresponding percentage among controls was 15
  (see Table 1). These individuals were excluded in
  longitudinal comparisons.
• The 31-year and 43-year temperament scores
  correlated largely among controls (n99)
  (Pearsons r NS 0.70, HA .65, RD .56, P .57),
  whereas correlations among psychotic individuals
  (n17) were weaker (NS .38, HA .51, RD .30, P
  .51). See Table 2.
• At the 31-year follow-up cases scored in average
  18.3 in NS, 20.3 in HA, 14.2 in RD, and 3.5 in P
  whereas controls scored 20.9, 13.2, 14.3, and
  4.3, respectively. Difference was statistically
  significant in HA (effect size d 1.49, plt.001).
  At age 43, mean scores (NS, HA, RD, P) were for
  cases 16.8, 19.4, 14.5, and 3.8 and for controls
  19.6, 12.9, 14.3, and 4.2, respectively.
  Differences were significant in NS (d 0.77,
  p.004) and HA (d 1.38, plt.001).

Table 1. Number of missing answers and infrequent
answers at 31- and 43- year follow-up studies of
the
  Cases (n28) Controls (n116) Sign. 
Age 31 years  
Missing gt 10 items 0 (0 ) 0 (0 ) NA
Infrequent gt 2 items 1 (4) 1 (1) P .35
Age 43 years  
Missing gt 10 items 2 (7) 3 (3) p .24
Infrequent gt 2 items 8 (29) 14 (12) p .04
Age 31 and 43 years  
Any above exclusion 11 (39) 17 (15) p .003
Table 2. Correlations between 31- and 43-year
studies in different temperament dimensions in
psychotic (cases) and non-psychotic (controls)
individuals.
Conclusion Individuals with psychotic disorders
may exhibit overendorsement of nonsensical items
on infrequency scales. Harm avoidance and
persistence are quite stable also in psychoses.
Novelty seeking and reward dependence had poor
stability in psychoses, which may be explained by
the clinical status of the individuals. Despite
individual differences in scoring between the two
follow-ups among cases differences between cases
and controls remained stable even after a long
follow-up.
Pearson correlations Cases (n17) Controls (n99)
Novelty Seeking .38 .70
Harm Avoidance .51 .65
Reward Dependence .30 .56
Persistence .51 .57
Correspondence Jouko Miettunen P.O.Box. 5000,
FIN-90014 University of Oulu, Finland Email.
jouko.miettunen_at_oulu.fi Fax. [phone]
169 Tel. [phone]
Acknowledgements This study has been supported
by the Academy of Finland, the European
Commission (EURO-BLCS, Framework 5 award
QLG1-CT-2000-01643), the NARSAD the Brain and
Behavior Research Fund, the Finnish Medical
Association, the Sigrid Jusélius Foundation, The
Finnish Medical Society Duodecim Oulu, DAAD
(German Academic Exchange Service), and US
National Institutes of Health (NIMH)
(5R01MH6370602).