Our research involved an exploratory intervention study by means of diaries, preceded by a screening questionnaire among almost 3000 young people (see flowchart). Below you will find a brief overview of the different types of measuring instruments used as well as a description of the intervention. For a more detailed description, please download our codebook and our study protocol below.
We measured (loss of) pleasure with the Domains of Pleasure Scale (DOPS). Our questionnaire also included items about extraversion, neuroticism, depression, lifestyle factors, drugs and alcohol use, life events, internalizing and externalizing problems, social comparison, and self-efficacy. The questionnaire was completed by 2937 people between 18 and 24 years old.
The 2937 participants also did an emotion recognition task. The participants in the intervention study completed the task multiple times. In this task, neutral looking faces gradually changed into happy, angry, scared or sad looking faces. This is also called a morph task. Participants had to indicate as quickly as possible what emotion they thought the face turned in to. We investigated if the extent to which emotions could be recognized quickly and accurately was associated with psychiatric disorders.
For the second part of the project, the diary study, we selected 69 participants with loss of pleasure and 69 control participants without loss of pleasure. The diaries consisted of questionnaires filled out three times a day with a fixed time interval of 6 hours between the measurements. The questionnaires included questions about sleep, positive and negative emotions, activities, social contacts, and food and drug intake. A complete overview of all the questions in the diary study can be found in our study protocol. The control participants filled out the questionnaires for 1 month, the participants with loss of pleasure for about 3.5 months.
In the participants with loss of pleasure, blood samples were collected every month during the study period, as well as 6 months and 12 months after the end of the study. In these blood samples, we measured serotonin, adrenaline, noradrenaline, dopamine, testosterone, CRP, TNF-alpha and IL-6. Before and after the tandem skydive we took 4 saliva samples, in which we measured alpha-amylase.
Following a month of diary assessments (observation month), participants were assigned randomly to 1 of 3 interventions:
• No intervention
• Personalized lifestyle advice (based on 30 days of diary assessments)
• Personalized lifestyle advice + a tandem skydive.
Subsequently, participants filled in the diaries again (month of intervention). After the intervention month participants were free to choose 1 of the 3 interventions.
Behavioral activation is an important component in existing interventions for depression and loss of pleasure. These behavioral interventions try to encourage patients to do things they enjoy.
The idea was that a personalized approach of providing tailor-made lifestyle advice would motivate participants more to actually get involved in activities than common advices.
Here you see a part of the lifestyle advice: feedback on the personal pleasure networks. Each participant received 2 to 3 lifestyle recommendations based on what was experienced as pleasurable by that particular participant during the past month.
People who suffer from pleasure loss are often not motivated to do things they can enjoy. Thus, they may be captured in a vicious circle of little motivation and little pleasure. An intensive thrill experience could help break this circle.
Previous research shows that intensive thrill experiences have a positive effect on the human psyche (thinking) and biology (hormone system).
We wanted to test whether an intense thrill experience like a tandem skydive could help to realize lifestyle changes.
For more information on the procedures of our study, please download our study protocol here.