IPT for psychotrauma;
The mediating role of interpersonal problems in the relationship between IPT and Posttraumatic Stress Disorder (PTSD)

Posttraumatic stress disorder (PTSD) is a severe limiting disorder that occurs
widely (Kessler, Chiu, Demler, et al. 2005). Almost every person in his life is
confronted with trauma (50-90%) (Kessler, Sonnega, Bromet, Hughes, & Nelson,
1995) 8% of these people develops PTSD (Breslau, Kessler, Chilcoat, Schultz,
Davis & Andreski, 1998).
The evidence-based treatments for PTSD are all based on the paradigm that
patients must expose themselves to memories of their trauma and preventing
avoidance, the so-called exposure-based treatments. Eye Movement
Desensitization Reprocessing (EMDR), Imaginairy Exposure (IE) are the two
leading evidence based treatments for PTSD in the Netherlands. Both treatments
are focused on exposure.
Exposure treatments, however, ignore another important problem within PTSD.
PTSD entails intrinsic & relational interpersonal and psychosocial problems.
These social factors play a key role in PTSD (Brewin, Andrews & Valentine,
2000). People with PTSD become distrustful, withdrawn, have increased vigilance
in contact with people (Bleiberg & Markowitz, 2005; Riggs, Byrn, Weathers &
Litz, 1998) and this involves a great burden for the patient's environment
(Beckham, Lytle & Feldman, 1996).
In addition, it appears that patients often find the treatment of PTSD very
intensive and frightening by exposing them to memories of the trauma (Foa,
Keane & Friedman, 2000). Because of this they are inclined to stop treatment
prematurely or do not even dare to start it.
For these reasons, treatment for interpersonal and social aspects, such as
Interpersonal Psychotherapy (IPT), could be an alternative. A recently
randomized study by Markovitz, Petkova, Neria, Van Meter, Zhao, Hembree,
Lovell, Biyanova & Marshall (2015) in which 110 patients with chronic PTSD were
treated with IPT, Imaginiary Exposure (IE) or relaxation therapy showed that
IPT has the same effect as IE on reducing the PTSD symptoms in this patient
group compared to progressive relaxation. This study also indicated that in
patients with comorbid depression, IPT had slightly more effect on the symptoms
than on patients without depressive symptoms.
Now that there is first proof of IPT to be effective in psychotrauma, the
question arises as to why this method of treatment is also effective in PTSD.

Mechanism of action behind IPT
IPT works by strengthening interpersonal relationships. Lipsitz & Markowitz
(2013) assume that the interpersonal problems are solved by IPT and that
symptom reduction occurs. Improving social support and reducing interpersonal
stress causes emotions to be processed and improve social skills.
It could be that this presumed working mechanism of IPT also works in this way
for PTSD patients. Patients recover from their isolation, experience less
stress in contact with others, so there is more room to process their emotions.
It is possible that patients, because of these psychosocial improvements, are
more likely to expose themselves to memories of the trauma, which further helps
to reduce PTSD symptoms. From the pilot study by Markowitz, Milrod, Bleiberg &
Marshall (2009), prior to their aforementioned RCT on IPT, PE and PR from 2015,
this also emerged. After the IPT treatment, patients themselves dared to expose
themselves more to memories of the trauma and avoided it less.

Question:
Does IPT affect the degree of interpersonal problems? And can this explain part
of the effect on the trauma-related complaints?

Hypothesis: Changes in PTSD during IPT treatment are explained by a decrease in
interpersonal problems

Design:
Using an observational study, patients with trauma-related complaints with a
cut off score of 44 or greater on PCL 5 will be offered treatment with IPT.

Patients receive 14 weekly treatment sessions according to the IPT protocol.
The adapted IPT protocol as described by Markowitz is used. This protocol has
been specially adapted for psychotrauma.

The IPT treatment will be carried out by GZ, KP and basic psychologists who
have followed an IPT course especially prior to the research. Within this
course attention is paid to familiarizing with the adapted protocol IPT with
PTSS from J.C. Markowitz (2017). During treatment, the practitioners are
supervised by a recognized IPT supervisor to ensure quality of the treatment.

Measurements
After inclusion (PCL-5 cut-off score 44>), a pre-measurement is taken. Then
measurements take place after 3 weeks, 6 weeks, 10 weeks and after 14 weeks the
final measurement.
* PTSD complaints: Post Traumatic Stress Disorder Checklist (PCL 5)
* Interpersonal problems: Inventory of interpersonal problems (IIP-32)
* Social and social functioning: Outcome Questionnaire-45 (OQ-45)?

14 sessions Interpersonal psychotherapy
Decrease the three previously mentioned questionnaires

Patients receive 14 weekly treatment sessions according to the IPT protocol.
The adapted IPT protocol as described by Markowitz is used. This protocol has
been specially adapted for psychotrauma. It is an EB standard treatment for
people with depression and is not invasive.

Filling in the questionnaires takes 30 minutes time. They are frequently used
questionnaires.

After inclusion (PCL-5 cut-off score 44>), a pre-measurement is taken.
Then measurements take place after 3 weeks, 6 weeks, 10 weeks and after 14
weeks the final measurement.

Questionnaires that are then taken are:
PTSD complaints: Post Traumatic Stress Disorder Checklist (PCL 5)
Interpersonal problems: Inventory of interpersonal problems (IIP-32)
General complaints: Outcome Questionnaire-45 (OQ-45)