The influence of maladaptive emotion regulation on inhibition in patients with eating disorders

Patients with eating disorders seem to have problems with behavioral
inhibition, which might have a large influence on their health. It is important
to gain more knowledge on their ability to inhibit impulses. Emotions could
play a role in this case, as it is well known that patients with eating
disorders have disruptions in their affective system and often experience
negative emotions. Patients with eating disorders often use suppression as an
emotion regulation strategy, which is maladaptive and costs a lot of
self-control. Possibly this influences their inhibitiory control, as inhibition
also costs self-control. Moreover, it is known that patients with binge-purge
related eating disorders often are impulsive, especially in reaction to
negativity. This could be due to the use of maladaptive emotion regulation
(suppression), as this leads to impaired self-control, and self-control is
required for inhibition. In this way, suppressing emotions could lead to
impaired inhibition. The link between emotion regulation and inhibition in
eating disorders has never been made before in literature, although this could
yield important implications for a better understanding of their behavior.

The current study aims to examine the influence of suppression as an emotion
regulation strategy on inhibition in patients with Anorexia Nervosa restrictive
type (AN-R), Anorexia Nervosa binge purge type (AN-BP), Bulimia Nervosa (BN),
and Binge Eating Disorder (BED) in comparison to healthy individuals. There are
three primary hypotheses. First, it is expected that amongst all participants,
the one*s that receive instructions to suppress their emotions show less
inhibition than the participants who get no regulation instructions. Second, ED
patients are expected to show less inhibition than control participants. Third,
an interaction effect of condition (suppression vs. no instruction) and group
(ED patients vs. control) is expected, as suppression leads to impaired
inhibition and ED patients will be more likely to suppress their emotions when
no regulation instruction is given.

Participants follow this procedure: they fill out questionnaires regarding
demographic variables, clinical characteristics and emotion experience
questionnaire. Then, instructions (suppression vs. no instruction) are given
and all participants will receive a negative emotion induction by means of a
film fragment. This fragment has been used before in psychological research
(Evers, Stok, & de Ridder, 2010; Smeets, Candel, & Merckelbach, 2004) and is
known to only temporarily elicit negative emotions. Afterwards, emotion checks
are measured. Subsequently, participants are asked to perform the SST to
measure inhibition. Afterwards, manipulation and emotion checks, and
questionnaires regarding eating disorder severity, trait self-control and
emotion driven impulsiveness will be administered.

Participants* collaboration will include one session (of about 50 minutes)
only. Therefore the burden is relatively small. All participants are asked to
fill out some questionnaires which can be considered a small burden.
Subsequently, participants will experience negative emotions as a result of
watching a film fragment. The procedure to evoke negative emotions has been
used very frequently by other researchers (e.g., Macht & Mueller, 2007). This
specific film fragment has also been used in previous studies (Evers et al.,
2010; Smeets et al, 2004). More importantly, no negative consequences were
experienced as a result of this procedure. Near the end of the study,
participants will perform the SST, a task measuring inhibition that has been
used several times before in patients with eating disorders (Bartholdy, Dalton,
O*Daly, Campbell, & Schmidt, 2016). 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.