Efficacy of happiness exercises

People with high levels of mental well-being have a better mental health and have a lower risk of developing common mental disorders. Positive psychology interventions have been developed to enhance mental well-being and prior studies have shown its efficacy. However, little is known about the efficacy of such positive psychology interventions in The Netherlands and in a general population study. The aim of this study is to examine the efficacy of different positive psychology interventions (Acts of Kindness and gratitude exercises) in a general population sample in The Netherlands compared to an active control condition as well as a wait-list control condition.

- How effective are the Acts of Kindness exercises with and without reflection compared to an active control condition and wait-list condition on mental well-being, flourishing, positive relations, gratitude, positive and negative emotions, optimism, anxiety, depression and stress?

- How effective are the gratitude exercises compared to an active control condition and wait-list condition on mental well-being, flourishing, positive relations, gratitude, positive and negative emotions, optimism, anxiety, depression and stress?

- Are positive effects of the happiness exercises maintained up to 12 months?

- Which specific subgroups benefit more from the happiness exercises than others? (men/women, education level, anxiety or depressive symptom level at baseline)

Baseline (T0), after 2 (T1) and 4 weeks (T2) short mediation questionnaires, post-test at 6 weeks (T3) and follow-up measures at 3 months (T4) and 12 months (T5) after baseline.

- Experimental group 1: One time per week, during 6 weeks performing 5 acts of kindness on one day. Writing the following day in an online happiness journal what they did and reflect on this.

- Experimental group 2: One time per week, during 6 weeks performing 5 acts of kindness on one day. Writing the following day in an online happiness journal what they did (no reflection).

- Experimental group 3: Performing a different gratitude exercise each week. Writing the following day in an online happiness journal where they are most grateful for.

- Active control condition: One time per week, during 6 weeks treating themselves 5 times on one day. Writing the following day in an online happiness journal what they did.

- Wait-list group: People are told that they can choose the happiness exercises they prefer to do, but after we collect some normal fluctuations in their level of happiness. Therefore, they will receive the happiness exercise after the 3 months follow-up questionnaire.