No Fun No Glory: lifestyle and loss of pleasure

This project focuses on anhedonia, generally defined as the inability to feel
pleasure in response to experiences that are usually enjoyable. Anhedonia is
one of the two core symptoms of depression. The concept of depression has been
heavily debated recently, because it is plagued by a heterogeneous symptom
profile. The US National Institute of Mental Health (NIMH) has recommended to
investigate psychopathology according to core processes that organize emotions
and behaviors rather than the existing diagnostic categories. One of the key
dimensions in this new framework for studying mental disorders is positive
emotionality. Anhedonia reflects a lack of positive emotionality and its study
is therefore a promising avenue towards a better understanding of affective
dysregulation.
Anhedonia is a major public health concern. It has particularly far-reaching
negative consequences in adolescence and young adulthood, when life course
decisions are made on the basis of what is satisfying. Anhedonia has proven
particularly difficult to counteract and predicts poor treatment response
generally. It has often been hypothesized that anhedonia can be deterred by a
healthy lifestyle and engagement in stimulating social and physical events.
However, it is quite unlikely that a one-size-fits-all approach will be
effective for everyone. In this study the effects of personalized lifestyle
advice based on observed individual patterns of lifestyle factors and
experienced pleasure will be tested. Regardless of whether the advice is
tailor-made or not, lifestyle changes are in general hard to achieve or
maintain for anhedonic persons, because a lack of drive to pursue rewarding
activities belongs to the core of their symptoms. As mild interventions are
often ineffective for this group, it is worth investigating whether a
noninvasive *rebooting* of the reward system can be accomplished. It is already
known that free fall provides strong boosts of dopamine, which is also involved
in reward related motivation. In our study it will be investigated whether a
tandem skydive preceding personalized lifestyle advice, positively influences
anhedonic young adults* abilities to carry out the recommended lifestyle
changes and whether this ultimately improves their self-reported pleasure.

Main objectives:
This exploratory intervention study is set out to examine effects of
tailor-made lifestyle advice, based on observed individual temporal patterns of
lifestyle factors and experienced pleasure, as a non-pharmacological means to
restore the pleasure of everyday activities and accomplishments. In addition,
we will test whether exposure to tandem skydiving, an experience known to
activate the dopamine system and to elicit strong emotions, can help to reboot
the reward system and hence foster the recommended lifestyle changes. The
effects of the interventions will primarily be examined with regard to
experienced pleasure, but changes in blood levels of potential biomarkers are
also taken into account.

Secondary objectives:
We will conduct a survey as a screening instrument to select eligible
participants for the intervention study. Besides being used for screening
purposes, the survey data provide the opportunity to elucidate the various
faces of pleasure loss, how often and in which combinations they occur in young
adults, and how they relate to, among other things, other mental health
problems and lifestyle factors. Little is known about the interrelations and
associated factors of these dimensions of anhedonia.

Our study design is an exploratory intervention study, preceded by a
cross-sectional survey as a screening instrument. Personalized lifestyle advice
will be based on a diary study, for which a replicated single-subject
time-series design will be used.

The group of 60 individuals without anhedonia will serve as a control group
only during the observation month of the diary study, in which no intervention
takes place, and will not partake in the intervention itself. After this first
month (observation month), the anhedonic participants are randomly assigned to
three groups. At the start of the second month (the first intervention month),
one group receives personalized lifestyle advice based on patterns observed in
the first month. The second group also receives personalized lifestyle advice,
but their advice will be closely followed by a tandem skydive. The third
anhedonic group serves as a control group and therefore receives neither
lifestyle advice nor a tandem skydive.
At the start of the third month (the second and last intervention month), all
participants are free to choose between: (1) no intervention, (2) (continued)
lifestyle advice, and/or (3) (another) tandem skydive.

Screening phase
Participants (N = 2000) will fill out a questionnaire that will take circa
50-60 minutes to complete. They will receive an incentive of a 10 Euro gift
card and, through a lottery, have a chance to win a city trip, tablet or gift
card.

Intervention phase
All anhedonic participants of the intervention study (N = 72) will be requested
to:
(1) fill out online questionnaires at six different time points, which will
take up to 45 minutes to complete each;
(2) fill out a daily questionnaire for three and a half months (three months
including intermediate periods), using a smartphone, which is estimated to take
about fifteen minutes per day;
(3) provide blood samples (one 10 ml EDTA K2E tube and one or two 4 ml EDTA K2E
tubes) at six different time points. Blood sampling will take place at the
*prikpoli* of the UMCG.

The anhedonic participants will be randomly assigned (stratified on gender) to
one of three intervention groups. Two of these groups will receive personalized
lifestyle advice. In one of these two groups, the lifestyle advice is followed
by a tandem skydive. After two months, all anhedonic participants can choose
whatever intervention they prefer, varying from nothing to (another) lifestyle
advice plus skydive. The skydive takes altogether 1,5 hours, traveling times
excluded. Before and after their first skydive, participants will be asked to
give a total of four saliva samples.

The non-anhedonic control group (N = 60) will fill out the online
questionnaires only at the first two time points and will be asked to fill out
a daily questionnaire three times a day during one month.

Depending on the specific group individuals are assigned to, different kinds of
benefits are expected. In all groups, the mere process of recording pleasure
and related factors will potentially improve participants* insight in their own
pleasure-related patterns. Personalized lifestyle advice is expected to
contribute to further insight in factors that affect pleasure, and practical
advice for regaining pleasure is expected to result in higher self-reported
pleasure rates. The group with a complementary skydive potentially benefits
even more in terms of symptom reduction, since this type of experience may help
to reboot the reward system which could positively influence the ability to
carry out lifestyle changes and ultimately also self-reported pleasure. Another
way in which the tandem skydive may work out positively for anhedonic
individuals is that conquering one*s fear is expected to boost self-confidence
and to make one feel more vibrant; altogether a promising starting point for
implementing lifestyle changes. Moreover, even independent of possible
subsequent changes in pleasure, performing a tandem skydive is in itself
expected to be a unique and unforgettable experience.

Besides the potential benefits, participants also receive an incentive as a
reimbursement for the time and effort invested, and to keep them motivated to
participate in our study. Anhedonic participants receive up to 500 Euro in
total and the non-anhedonic control group up to 75 Euro.

Regarding the risks: tandem skydiving is relatively safe. Data acquired from
the *Koninklijke Nederlandse Vereniging voor Luchtvaart* (KNVvL: Royal
Netherlands Aeronautical Association) show that tandem skydiving is the safest
form of skydiving. For 2005-2012, the KNVvL reported 0.29-0.91 injuries per
1000 tandem skydives. No fatalities have occurred in the Netherlands with
respect to tandem skydives, despite the fact that around 10000 tandem skydives
per year take place with a total of 157284 tandem skydives between 1999 and
2013. The incidents that did occur in the Netherlands were usually caused by
people not lifting their legs upon landing, resulting in ankle or leg-injuries.
Our participants will receive safety-instructions before their skydive and all
and standard safety guidelines will be followed by Skydive Association
Eelde-Hoogeveen. Based on these numbers and safety-guidelines we do not expect
our participants to get injuries or accidents, but of course we cannot exclude
this possibility. Furthermore, there is no evidence of long-term adverse
effects of the acute stress elicited by skydiving.