Veterans with Post-traumatic Stress Disorder Working dog Research (V-PWR) 2.0 - The Influence of Service Dogs on Military Veterans with Post-traumatic Stress Disorder and their Families

In a literature review van Houtert et al. (2018) noted that much of the
presented evidence of post-traumatic stress disorder (PTSD) service dog
effectiveness was either based on anecdotal documentation, self-reflection by
subjects, or indirect study of the topic. Therefore, van Houtert et al. (2022)
evaluated and used existing techniques to study the effects of PSDs on military
veterans. The results of questionnaires were compared to objective parameters,
including salivary cortisol samples, heartrate measurements and activity
levels. Four subject groups were investigated; veterans with PTSD and a service
dog, veterans with PTSD and a companion dog, veterans with PTSD without a dog
and a control group of veterans without PTSD. Results of this study were
promising, as veterans with PTSD who had a service dog showed less PTSD related
symptoms, better wellbeing and better sleep quality compared to those with a
companion dog and those without a dog. However, no significant results were
found for the objective parameters, aside from the fact that veterans with a
service dog tended to walk more than individuals in the control group. Van
Houtert et al. (2022) concluded that the use of objective measurement methods
to investigate PSD effectiveness needs more research. Furthermore, during the
study by van Houtert et al. (2022), additional questions were raised, which we
aim to answer in the current study.

Firstly, existing research suggests that the partner and children of a veteran
are also negatively affected by the veteran*s PTSD. To date, literature on the
effects of PTSD service dogs (PSDs) has almost solely focused on the effect of
PSDs on the veteran, rather than on the family as a whole. The few studies that
have investigated the effects of PSDs on the families of veterans provide
promising results, but these results are again based on anecdotal documentation
or self-reflection. Therefore, this study would like to investigate the
influence of PSDs on the partner and children of military veterans with PTSD,
using both subjective and objective measurements.

Additionally, the current study will add additional objective parameters,
including salivary oxytocin. Oxytocin is a hormone and neurotransmitter that
manages key aspects of the reproductive system of males and females, including
childbirth. Besides, oxytocin is known for various health benefits, including
reduced stress and improved cardiovascular function. The hormone is also
increasingly recognized to have a role in human-dog interactions, and it is
suggested that PSDs enhance oxytocin levels in veterans with PTSD. Therefore,
we want to investigate the effect of interactions between veterans with PTSD
and their service dog on oxytocin levels in both, as an increase in oxytocin
levels could promote human-dog bonding as well as the overall health of the
veteran.

This study will also look into the effects of service dogs on heart rate
variability (HRV) of the veterans. Existing research shows that humans with
PTSD have lower HRV at baseline and throughout different conditions than
individuals without PTSD. Therefore, this study aims to investigate whether
PSDs increase HRV in veterans with PTSD.

Finally, this study aims to investigate the effect of retirement of the service
dog on the veterans, as this is something that all veterans with a service dog
will have to deal with at some point. Although retirement of the service dog is
inevitable for all humans with a service animal, research on this particular
topic is scarce. Ng and Fine (2019) recommended studies to explore the
emotional and practical experience when preparing for and adjusting to
retirement of their service animal, which is what this study aims to
investigate.

The aim of this study is to identify whether the availability of a PSD for
military veterans with PTSD coincides with clinically significant changes in
wellbeing, behaviour and functioning in veterans and their families compared to
veterans with PTSD and their families who are on the waitlist for a PSD.

This study consists of several measurement moments that take place every six
months during three years.

A single measurement moment consists of seven days. On the 1st and 7th day,
participants are visited by the researchers. For veterans with a service dog
the 1st visit takes about 76 minutes, the second 55 minutes. The total time
load for veterans with a service dog is estimated at 186 minutes per
measurement moment. For veterans in the control group the 1st visit takes
about 66 minutes, the second 40 minutes. The total time load for veterans in
the control group is estimated at 141 minutes per measurement moment.
For partners of the veterans the 1st visit takes about 56 minutes, the second
40 minutes. The total time load for partners is estimated at 131 minutes per
measurement moment. For children of subjects the 1st visit takes about 46
minutes, the second visist 25 minutes. The total time load for children is
estimated at 91 minutes per measurement moment.
On the 5th and 6th day of the measurement moment, participants will be asked to
conduct measurements themselves. This is expected to take around 20 minutes per
day.

For each measurement moment participants will be asked to participate in
multiple measurements: First of all, veterans with a service dog will be asked
to fill in five (participants without partner or children), six (participants
with partner or children) or seven (participants with partner and children)
questionnaires per measurement moment. Veterans on the waitlist for a service
dog will be asked to fill in three (participants without partner or children),
four (participants with partner or children) or five (participants with partner
and children) questionnaires per measurement moment. The partner of each
veteran subject is asked to fill in three (participants without children) or
four (participants with children) questionnaires per measurement moment.
Children of subjects are asked to fill in three questionnaires. All
questionnaires will be spread over the two house visits by the researcher.

Participants are asked to take 5 saliva samples per day of themselves and their
service dogs for 2 days. This gives a total of 10 samples for humans and 10 for
dogs. Samples for humans are taken by spitting in a saliva tube. Samples for
service dogs are taken with a swap which must be kept in the mouth of the dog
for 1 minute to passively absorb saliva. Because of potential sample
contamination, participants are asked to eat or drink nothing but flat water
for 30 minutes before and during these measurements.

Some participants will be asked to wear a physiological measuring instrument
for a period of 48 hours. This instrument has the size of a watch and registers
heart rate, heart rate variability, and activity while being worn.

At the end of the study, a (small) hair sample from each subject is asked for
cortisol analysis.

Aside from the measurements during the measurement moment, veteran participants
will be asked to come to an external location once to participate in an
"interaction day". This is expected to take one morning or one afternoon. The
external location is yet to be decided. During this interaction day,
participants will be asked to perform an assignment with their service dog.
Saliva samples will be taken from both the veteran and the service dog before
and after completing the assignment. These saliva samples will be used to
assess levels of the hormones cortisol and oxytocin.

Aside from the measurements during the measurement moment, participants whose
service dog will retire during this study will be asked to participate in at
least one semi-structured interview, in order to investigate the effects of
service dog retirement. This interview is assumed to take around 30 minutes,
and contains questions about the emotional and practical consequences of
service dog retirement for the veteran. Depending on the willingness of
subjects to participate, subjects will be asked to participate in a second
interview a few months after service dog retirement, in order to investigate
the effects of service dog retirement on the longer term.

Data as described above will be encripted by assigning a code to each subject.
The key for this code is known only to the researchers.

The researchers are not aware of any risks associated with participation in
this study.

The estimated time load for participating veterans with a service dog is 186
minutes per measurement moment. The estimated time load for participating
veterans in the control group is 141 minutes per measurement moment. Veterans
participate in a maximum of 6 measurement moments, which take place every six
months during three years.

Aside from the measurement moments, veteran participants will be asked to come
to an external location once to participate in an "interaction day". This is
expected to take one morning or one afternoon. Veterans whose service dog will
retire during this study will be asked to participate in at least one
semi-structured interview that will take around 30 minutes. Depending on
willingness of subjects to participate, subjects will be asked to participate
in a second interview a few months after service dog retirement, which will
also take around 30 minutes.

For partners of the veterans the estimated time load is 131 minutes per
measurement moment. For children of the veterans the estimated time load is 91
minutes per measurement moment. Partners and children of the veterans will also
participate in a maximum of 6 measurement moments, which take place every six
months during three years.