Dunn EW, Aknin LB, Norton MI Spending money on others promotes happiness. Science. 2008 Mar 21;319(5870):1687-8. doi: 10.1126/science.1150952. Erratum in: Science. 2009 May 29;324(5931):1143.
Grant, A M., Campbell, E. M., Chen, G., Cottone, K., Lapedis, D., & Lee, K. (2007). Impact and the art of motivation maintenance: The effects of contact with beneficiaries on persistence behavior. Organizational Behavior and Human Decision Processes, 103(1), 53-67.
Rhodes RE, Fiala B, Conner M A review and meta-analysis of affective judgments and physical activity in adult populations. Ann Behav Med. 2009 Dec;38(3):180-204. doi: 10.1007/s12160-009-9147-y. Review.
Ryan RM, Deci EL On happiness and human potentials: a review of research on hedonic and eudaimonic well-being. Annu Rev Psychol. 2001;52:141-66.
Segar ML, Eccles JS, Richardson CR Rebranding exercise: closing the gap between values and behavior. Int J Behav Nutr Phys Act. 2011 Aug 31;8:94. doi: 10.1186/1479-5868-8-94.
Segar ML, Richardson CR Prescribing pleasure and meaning: cultivating walking motivation and maintenance. Am J Prev Med. 2014 Dec;47(6):838-41. doi: 10.1016/j.amepre.2014.07.001. Epub 2014 Aug 26. Review.
Thoits PA, Hewitt LN Volunteer work and well-being. J Health Soc Behav. 2001 Jun;42(2):115-31.
Prosocial Exercise: Does Exercising for Charity Result in Greater Well-Being and Physical Activity?
Interventional studies are often prospective and are specifically tailored to evaluate direct impacts of treatment or preventive measures on disease.
Observational studies are often retrospective and are used to assess potential causation in exposure-outcome relationships and therefore influence preventive methods.
Expanded access is a means by which manufacturers make investigational new drugs available, under certain circumstances, to treat a patient(s) with a serious disease or condition who cannot participate in a controlled clinical trial.
Clinical trials are conducted in a series of steps, called phases - each phase is designed to answer a separate research question.
Phase 1: Researchers test a new drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
Phase 2: The drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety.
Phase 3: The drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
Phase 4: Studies are done after the drug or treatment has been marketed to gather information on the drug's effect in various populations and any side effects associated with long-term use.
