The influence of negative emotions on decision making in women with restrictive and purging type Anorexia Nervosa in comparison to healthy women

AN patients have impaired decision making ability. They are inclined to base
their decision on the short term gains (not eating to loose weight and
(temporarily) reduce anxiety) without considering future consequences (health
problems and no recovery). A possible factor underlying these decision making
deficits are the affective disturbances seen in AN patients. Examples of
affective disturbances are emotional problems such as disturbed emotion
recognition and maladaptive emotion regulation, but also have to do with more
fundamental disturbances such as abnormalities in the dopaminergic system.
Another important factor is the personality differences between restrictive and
purging AN patients. AN-P patients seem to have more impulsive characteristics
as well as show more impulsive behaviours than AN-R patients, especially in
response to negative affect (also referred to as urgency). However, so far no
study on decision making in AN patients differentiated between different
subtypes. It may be that AN-P and AN-R patients both have difficulties making
adaptive decisions, but AN-P patients may show even more impaired decision
making in response to negative affect.

The current study aims to examine the influence of negative emotions on
decision making ability in female patients with Anorexia Nervosa restrictive
(AN-R) and purging (AN-P) type in comparison to healthy women. There are two
primary hypotheses: both patients groups (AN-R and AN-P) will show decision
making impairments in comparison to a healthy control group, and AN-P patients
will be more impaired after experiencing negative emotions while AN-R patients
will show no difference in their decision making ability. Secondary objectives
of this study are to compare different kinds of decision making by using two
different measures: the Iowa Gambling Task (IGT) and the Game of Dice task
(GD), and to compare the findings with the results of the same experiment in
patients with binge eating problems (Bulimia Nervosa and Binge Eating
Disorder), that we recently conducted. The expectations related to this
objective are that AN-P patients will resemble patients with binge eating
problems, while this will not be the case for the AN-R patients.

Three groups can be distinguished and in each group a negative emotion
induction will be conducted among half of the participants by means of a film
fragment. This fragment has been used before in patients with Anorexia Nervosa
and is known to temporarily elicit negative emotions. The other half of the
participants will watch a neutral film fragment and will therefore not
experience negative emotions. Subsequently, participants are asked to perform
the IGT and the GD task to measure different aspects of decision making
performance. Prior to the emotion induction, questionnaires will be
administered to measure several relevant personality characteristics and eating
disorder severity.

Participants* collaboration will include one session (of about 50 minutes and
in the control group about 80 minutes) only. Therefore the burden is relatively
small. All participants are asked to fill in some questionnaires which can be
considered a small burden. Subsequently, half of the participants will
experience negative emotions as a result of watching a film fragment, and the
other half will not experience negative emotions. This procedure to evoke
negative emotions has been used very frequently by other researchers (e.g.,
Jakobs et al., 1999; Macht & Mueller, 2007) and specifically also by BN and BED
patients in a participating clinic (Ursula Centre Eating Disorders, 2009). This
film fragment has also been used in a study with AN patients in Altrecht Eating
Disorders Rintveld that was approved by the Ethical Committee of the UMCU
(Zonnevylle-Bender et al., 2005). Furthermore, we recently conducted a study
using the exact same procedure (except for the GD task) in BN and BED patients
(CCMO number NL21460.041.08 and registration number of the METC 08-426/E) that
was also approved by the Ethical Committee of the UMCU. More importantly, no
negative consequences were experienced as a result of this procedure. Near the
end of the study, participants will perform both the IGT and the GD task which
are both card games that been used several times before in patients with eating
disorders as well as in other psychiatric disorders (e.g., OCD, depression,
schizophrenia). Patients find these games interesting to play. The entire
procedure is considered safe.
Prior to the study, participants are ensured that their treatment will not be
influenced in any way by participating in the study and they are told that they
can stop participating in the study at any time without reason. At the end of
the study, participants will be thoroughly debriefed. They are instructed that
they can contact the researchers or the therapist anytime in case of question
or any inconveniences as a result of their participation.