How does clients' empathy and mental flexibility relate to treatment outcome? A longitudinal study of group psychotherapy and group cohesion in personality disorders.

The treatment of personality disorders (PD) has gained vast attention in the
last years and treatment options have increased. PD are common, with a
prevalence rate of about 13,1% in the western world (Zimmerman e.a., 1989;
Black e.a., 1992; Maier e.a., 1992; Moldin e.a., 1994; Klein e.a., 1995;
Lenzenweger e.a., 1997; Torgersen e.a., 2001; Samuels e.a., 2002; Grant e.a.,
2005). Research has shown that in general, effect sizes of the treatment of PD
are good (Cohen*s d between 1.1 and 1.8). However, several comments need to be
made here. First, these studies only focus on certain personality disorders
under particular treatment conditions, making it difficult to generalize the
results (Leichsenring & Leibing, 2003; Perry e.a., 1999). Secondly, high
drop-out rates (44-66%) are common (Skodol e.a., 1983; Gunderson e.a., 1989;
Kelly e.a., 1992; Perry e.a., 1999; Chiesa e.a., 2000). And it is still unclear
which clients do not seem to profit (enough) from current treatment options. As
PD are one of the most common psychiatric disorders (Eurelings-Bontekoe,
Verheul, & Snellen, 2009) and PD are by definition associated with a
significant burden on the individuals with the disorder, those around them and
on society in general (Coid, Yang, Tyrer, Roberts, & Ulrich, 2006), with
substantial societal costs, effective treatment is sorely needed.
Currently there is little insight as to which client*s factors influence the
course and outcome of these treatments (Kenniscentrum
Persoonlijkheidsstoornissen, 2013). Several interconnecting factors could be of
interest here. These are group cohesion, empathy and mental flexibility. It has
been suggested that group cohesion in group psychotherapy for clients with PD
plays an important role in outcome (Burlingame, Fuhriman, & Johnson, 2002;
Hoijtink, 2003; MacKenzie, 1994; Marziali, Munroe-Blum, & McCleary, 1997).
Empathy is suggested to be a contributing factor to group cohesion (Roarch &
Sharah, 2012). Also has it been proposed that there is a link between empathy
and mental flexibility (Harmon-Jones & Winkielman, 2007). The goal of group
psychotherapy is to change rigid dysfunctional patterns (mental flexibility) of
the group members by empathising with each other (empathy) and experiencing
relatedness with each other as a group (group cohesion). However, as to date no
studies have investigated these factors. The current study thus investigates
these with respect to treatment outcome in order to aid in selecting patients
for the current treatment options, and in the development of better treatment
options for the current drop outs and non-responders.

If the hypotheses of this study are confirmed, this might have important
implications for the allocation of patients to group or individual treatments.
As it is expected that patients with limited mental flexibility and empathy
experience less group cohesion, they may not benefit from group psychotherapy
or even have increased drop-out rates and individual therapy might thus be more
beneficial. Yalom (2005) states that premature termination from group
psychotherapy is bad for the client, and also detrimental for the group.
According to him, dropouts in groups may delay the maturation of a group for
months. Until now, contra-indications were assumed on the basis of clinical
judgement or co-morbid psychopathology. This research aims to also
differentiate (contra-)indications on the basis of cognitive functioning and
more general traits, which do not have to be pathological per se. By
identifying (contra-)indications more effectively for this group treatment
time, costs, frustration and even damage in clients and/or therapists can be
prevented.
With this current research the following research questions are answered: does
the level of empathy and the level of mental flexibility, measured at baseline
(T1), have an effect on group cohesion, measured during the treatment (T2),
consequently influencing the level of treatment outcome, measured after
treatment (T3)? It is expected that the level of client*s empathy and mental
flexibility is a predictor of the level of treatment outcome and that this
effect is partly explained by the mediator group cohesion. The second research
question asks, does the level of client*s empathy and mental flexibility,
measured at baseline (T1), have an effect on group cohesion, measured during
treatment (T2), consequently influencing the level of client*s empathy and
mental flexibility, measured after treatment (T3)? It is expected that the
level of client*s empathy and mental flexibility increases over time of
treatment and this effect is partly explained by the mediator group cohesion.

The study has an observational, naturalistic, prospective longitudinal design.

For the first testing participants will be asked to come to the location that
they follow their treatment at and will be tested by research assistants, which
have been trained by the researcher. The procedure will be executed in a quiet
room and some of the instruments are presented on paper and some will be
presented on a computer. It is expected that the testing will take
approximately an hour of which participants can take a break in, if they
desire. For the next two testings the participants can fill out the
questionnaires on a computer from their home. They will get a reminder from the
research assistant and will be asked to fill out the questionnaires and mail
them back to the research team. This will take approximately 15 minutes. For
the last testing the procedure of the first testing will be repeated. It is
expected that the burden on the participants will be time and energy. For the
questionnaires all short form versions have been chosen in order safe guard
against unnecessary toll for the participants.