Table 2.

Detailed description of interventions

Study	Intervention Description	Comparator Description	HB^a Focus
Randomized controlled trials
Boutin-Foster et al., 2016²⁴	Positive affect induction. In addition to comparator content, received the positive affect and self-affirmation induction protocol and motivational interviewing. Positive affect strategy included focusing on positive thoughts that made them feel good throughout the day and receipt of unexpected gifts on a bimonthly basis. Self-affirmation strategy included instructing participants to think of core values that made them proud whenever they encountered a situation that would make it difficult to adhere to medications. Motivational interviewing for medication adherence was also provided.	Provided with educational workbook about hypertension and asked to develop a behavior contract that specified steps they would take to adhere to hypertension medications. Follow-up calls checked in on adherence to contract.	Yes
Bradshaw et al., 2007²⁵	Building resiliency. The Resiliency Training Approach for Diabetes is an educational/experiential intervention intended to assist people with diabetes to initiate and develop self-directed behavior change. Approach focused on the psychosocial enrichment of the individual and the supportive relationship between the individual and their environment. Modules reinforced diabetes education literature and built on the concept of resiliency.	Treatment as usual from the Diabetes Center plus pedometer provision	Yes
Celano et al., 2020³⁵	Enhancing gratitude, personal strengths, and meaning in life. The positive psychology-motivational interviewing intervention included provision of a treatment manual, a copy of the Learning to Live with Heart Failure guide, and a pedometer. Each phone session included a positive psychology exercise and discussion of a health behavior goal using motivational interviewing. Positive psychology exercises were grouped into three modules: gratitude (gratitude for positive events, expressing gratitude, capitalizing on positive events), strengths (remembering past successes, using personal strengths), and meaning (acts of kindness, the good life, enjoyable and meaningful activities). Motivational interviewing focused on adherence to physical activity, a low sodium diet, and medications.	Active control: motivational interviewing alone. Participants received a treatment manual, the Learning to Live with Heart Failure guide, and a pedometer plus weekly phone calls about heart failure-specific health behaviors and identified potential behavior change. Treatment as usual: no phone sessions or treatment manual.	Yes
Chandler et al., 2015⁴⁷	Building resiliency. The Empower Resilience Intervention is a psycho-educational intervention that applies the ABCs of resilience (Active coping, Building strength, Cognitive flexibility, and Social support) using mindfulness-based stress reduction, education, structured writing, and social support with peer and facilitator interaction. Weekly topics included personality assets, resilience, adverse childhood experiences, physical health, preferred future, and social support. Each session included a brief guided mindfulness meditation, reviewing homework, learning about a topic, and freewriting on that topic.	Not clearly specified. Most likely not provided any intervention.	No
Emmons et al., 2003a²⁶	Targeting gratitude. Participants were prompted to write about up to 5 things in their lives they are grateful or thankful for that week.	In the "hassles" condition, participants were provided with a prompt to think back over today and list up to 5 hassles in their lives. In the "events" condition, participants were provided with a prompt to write up to 5 events in the last week that had an impact on them.	No
Emmons et al., 2003b²⁶	Targeting gratitude. Participants were prompted to write about up to 5 things in their lives they are grateful or thankful for that day.	In the "hassles" condition, participants were provided with a prompt to think back over today and list up to 5 hassles in their lives. In the "downward social comparison" condition, participants were provided with a prompt about comparing oneself to others and asked to write down ways in which one is better off than others.	No
Emmons et al., 2003c²⁶	Targeting gratitude. Participants were prompted to write about up to 5 things in their lives they are grateful or thankful for that day.	No writing assignment provided	No
Huffman et al., 2019³⁸	Enhancing gratitude, personal strengths, and meaning in life. The positive psychology-motivational interviewing intervention included provision of a treatment manual and a pedometer. Each phone session included a positive psychology exercise and discussion of physical activity promotion using motivational interviewing. Positive psychology exercises were grouped into three modules: gratitude (gratitude for positive events, expressing gratitude, capitalizing on positive events), strengths (remembering past successes, using personal strengths), and meaning (acts of kindness, enjoyable and meaningful activities, the good life).	Motivational interviewing and health education: participants received a treatment manual and a pedometer plus weekly phone calls about cardiac-specific health behaviors and identified potential behavior change.	Yes
Huffman et al., 2020³⁶	Enhancing gratitude, personal strengths, and meaning in life. The positive psychology-motivational interviewing intervention included provision of a treatment manual and a pedometer. Each phone session included a positive psychology exercise and discussion of a physical activity goal using motivational interviewing. Positive psychology exercises included: gratitude for positive events, gratitude letter, enjoyable and meaningful activities, recalling past successes, using personal strengths, and acts of kindness.	Motivational interviewing-enhanced behavioral counseling: time- and attention-matched control that focused on diabetes self-care behaviors (diet, physical activity, medication adherence, overall diabetes self-care). Participants received a treatment manual and a pedometer plus weekly phone calls about diabetes-specific health behaviors and identified potential behavior change.	Yes
Jaser et al., 2014⁴⁸	Positive affect induction. The positive affect intervention was designed to increase positive affect through gratitude, self-affirmation, small gifts, and parental affirmations. Participants’ parents were instructed to provide weekly affirmations to participants on topics other than diabetes self-care by writing a short note or sending a text message. Participants were instructed to take a moment to notice things that made them happy (gratitude) and to remember something that they were proud of (self-affirmation) when it was time to check their blood sugar. They were reminded to use gratitude and self-affirmation during follow-up phone calls. Participants were also mailed a small gift every 2 weeks.	Mailed diabetes education materials every 2 weeks.	No
Joutsenniemi et al., 2014²⁷	Enhancing happiness. Participants received emails every 4-5 days that included short texts that gave general information about happiness. The emails also included one of 4 different happiness exercises: good deeds, gratitude, optimism, and reducing rumination.	Received emails every 4-5 days that included short texts that gave general information about happiness.	No
Kahler et al., 2015⁴⁴	Enhancing gratitude, personal strengths, and meaning in life. Standard smoking cessation as in control plus positive psychotherapy. At each session, positive psychology exercises were introduced, and participants were given related homework assignments. Exercises included Three Good Things, a Gratitude Letter, Savoring, Active-Constructive Responding, Savoring Acts of Kindness, and utilize their personal “Signature Strengths” (e.g., bravery, curiosity)—as assessed via the Values in Action Survey—to help them during their quit attempt.	Standard smoking cessation focused on problem solving regarding high-risk situations for smoking relapse, providing support, and encouraging participants to seek outside social support for quitting smoking. All participants received transdermal nicotine patch beginning on their scheduled quit date. Sessions also included 20-30 min of progressive muscle relaxation.	Yes
Kersten et al., 2016²⁸	Targeting optimism. Participants were instructed to write about a past event that makes them feel nostalgic.	Write about an ordinary life event.	No
Lee et al., 2019²⁹	Building social support. Attended pedometer walking exercise training sessions, plus received 6 positive education sessions designed based on self-determination theory and broaden-and-build theory to enhance positive self, emotion, motivation and self-efficacy to walk at least 30 min per day at least five times per week with family support and walking exercise companions. Sessions focused on instilling competency and self-efficacy of walking exercise, networking and becoming acquainted with other participants; gaining familiarity with communication skills required for positive support, sharing positive emotions associated with successful walking exercise to enhance partnership, increasing autonomy in walking exercise every day and building a healthy lifestyle.	In the pedometer walking exercise control, participants were encouraged to walk for at least 30 minutes 5 times/week and were given a booklet to write down pedometer readings each day. They walked on their own without any training. The pedometer walking exercise training control attended 30-minute walking exercise training sessions with a coach 3 times/week where heartrate was monitored and gradually increased throughout the intervention.	Yes
Mancuso et al., 2012³⁰	Positive affect induction. In addition to comparator content, participants received the positive affect and self-affirmation induction protocol. Positive affect strategy included focusing on positive thoughts throughout the day and receipt of unexpected gifts on a bimonthly basis. Self-affirmation strategy instructed participants to think of things they were proud of when fulfilling the physical activity contract. Follow-up calls assessed adherence to the physical activity contract and how they applied positive affect and self-affirmation skills.	Provided with educational workbook about asthma, a pedometer, and asked to develop a behavior contract that specified the physical activity they would do. Follow-up calls checked in on adherence to contract.	Yes
Mann et al., 2001⁴⁵	Targeting optimism. Instructed to write about a positive future where they only must take 1 pill each day for HIV. Told to write twice a week for 4 weeks for at least 10 minutes each time in provided journal.	Not asked to write in journals or imagine an optimistic future. Tried to time match first session with longer consent process	No
Moskowitz et al., 2017³¹	Enhancing gratitude, personal strengths, and meaning in life. Taught 8 empirically supported behavioral and cognitive skills for increasing positive affect: noting daily positive events, capitalizing on positive events, gratitude, mindfulness, positive reappraisal, focusing on personal strengths, setting and working toward attainable goals, and small acts of kindness	Also had 5 in-person sessions followed by 6th session by phone. Time/attention matched, consisted of an interview about different topics	No
Ogedegbe et al., 2012³²	Positive affect induction. Educational workbook included an additional chapter about benefits of positive moments in overcoming obstacles to medication adherence. Positive affect strategy included focusing on positive thoughts that made them feel good throughout the day and receipt of unexpected gifts on a bimonthly basis. Self-affirmation strategy instructed participants to think of things they were proud of when fulfilling the physical activity contract. Follow-up calls assessed adherence to the medication contract and how they applied positive affect and self-affirmation skills.	Provided with culturally tailored educational workbook designed to (1) enhance knowledge about hypertension, (2) improve self-management behaviors, and (3) support goal-setting. Participants also signed a behavioral contract where they committed to taking medications as prescribed. Follow-up calls assessed behavioral contract adherence and confidence to take meds.	Yes
Peterson et al., 2012³³	Positive affect induction. In addition to comparator content, participants received the positive affect and self-affirmation induction protocol. Positive affect strategy included focusing on positive thoughts throughout the day and receipt of unexpected gifts on a bimonthly basis. Self-affirmation strategy instructed participants to think of things they were proud of when fulfilling the physical activity contract. Follow-up calls assessed adherence to the physical activity contract and how they applied positive affect and self-affirmation skills.	Provided with culturally tailored educational workbook called "Living with Heart Disease: Taking Control after Angioplasty", a pedometer, and asked to develop a behavioral contract for self-selected physical activity. Follow-up calls checked in on adherence to contract.	Yes
Phillips et al., 2017³⁴	Positive affect induction. In addition to comparator content, participants received the positive affect and self-affirmation induction protocol. They were instructed to identify small things that made them feel good and to think about those things when they first woke up and throughout their day. For the self-affirmation component, participants were asked to think of a proud moment in their lives and to remember that moment when faced with barriers to their new behavior goals	Small changes to eating: participants were guided to select one of 10 small change eating strategies to address their eating challenges (e.g., prepare main meal at home). They also set self-selected physical activity goals and made behavioral contract to adhere to goals at least 6 days/week.	Yes
Single-arm studies
Celano, Freedman et al., 2018³⁹	Enhancing gratitude, personal strengths, and meaning in life. The positive psychology-motivational interviewing intervention included provision of a treatment manual, a copy of the Learning to Live with Heart Failure guide, and a pedometer. Each phone session included a positive psychology exercise and discussion of a health behavior goal using motivational interviewing. Positive psychology exercises were grouped into three modules: gratitude (gratitude for positive events, expressing gratitude), strengths (remembering past successes, using personal strengths), and meaning (acts of kindness, enjoyable and meaningful activities). Motivational interviewing focused on adherence to physical activity, a low sodium diet, and medications.		Yes
Celano, Albanese et al., 2018⁴⁰	Enhancing gratitude, personal strengths, and meaning in life. The positive psychology intervention included provision of a treatment manual. At each session, a new positive psychology exercise was introduced, and participants were encouraged to complete it during the week. Their practice was then reviewed the following week. Exercises included: enhancing gratitude for positive events, using personal strengths, expressing gratitude, capitalizing on positive events, remembering successes, performing enjoyable and meaningful activities, identifying humor in everyday life, and performing acts of kindness. This factorial trial compared effects of three treatment components: completing positive psychology exercises weekly vs. daily, inclusion/exclusion of motivational interviewing for a health behavior goal, and presence/absence of booster sessions after the core intervention. Therefore, participants were randomized on all three of these factors. For participants who received it, motivational interviewing focused mainly on physical activity though participants could choose another health behavior goal once they completed their activity goal. Booster sessions focused on ongoing use of positive psychology skills in everyday life and ongoing physical activity goal progress.		Yes
Celano et al., 2019³⁷	Enhancing gratitude, personal strengths, and meaning in life. The positive psychology-motivational interviewing intervention included provision of a treatment manual and a pedometer. Each phone session included a positive psychology exercise and discussion of physical activity promotion using motivational interviewing. Positive psychology exercises were grouped into three modules: gratitude (gratitude for positive events, expressing gratitude, capitalizing on positive events), strengths (remembering past successes, using personal strengths, using perseverance, humor in everyday life), and meaning (acts of kindness, enjoyable and meaningful activities, the good life).		Yes
DuBois et al., 2016⁴²	Enhancing gratitude, personal strengths, and meaning in life. The positive psychology intervention included provision of a treatment manual which described 6 positive psychology exercises that were also taught during treatment sessions. These included gratitude for positive events, personal strengths, gratitude letter, enjoyable and meaningful activities, recalling past successes, and acts of kindness. Participants were taught the skill, asked to practice it over the week and write about it, and then their practice was reviewed the following week.		No
Hoeppner et al., 2019⁴³	Enhancing gratitude, personal strengths, and meaning in life. The Smiling Instead of Smoking (SiS) app engages participants in daily positive psychology exercises over three weeks and provides behavioral support via three app-delivered sessions and ad lib user-initiated tools. One of three exercises is selected at random by the app each day. These include three good things, savoring, and experiencing kindness. Behavioral sessions assess smoking amount and triggers, advise quitting, assess readiness to quit and barriers, assist in setting a quit day, and provide support during quit attempt. Users could choose to monitor cigarette use, specify reasons for quitting, set reminders, enlist social support, view information on benefits of quitting, and address common concerns about quitting.		Yes
Millstein et al., 2020⁴¹	Enhancing gratitude, personal strengths, and meaning in life. The positive psychology-motivational interviewing intervention included provision of a treatment manual and a Fitbit. Each group session included physical activity education and goal-setting using a motivational interviewing approach, plus a positive psychology exercise introduced each week paired with a relevant physical activity topic. Positive psychology exercises included: gratitude for health, perseverance, personal strengths, enjoyable and meaningful activities, remembering past successes, capitalizing on goals and health, and the good life. Group sessions ended with a group walk around the neighborhood.		Yes
O'Brien et al., 2020⁴⁶	Positive affirmations and building resiliency. State of Mind Ireland-Higher Education aims to develop knowledge and application of positive mental health strategies, increase well-being and prevent ill mental health, reduce mental health stigma and promote help-seeking behavior, and increase physical activity. Positive psychology components include discussing resilience to stress and positive affirmations. The intervention also includes education and goal-setting around physical activity.		Yes

HB: health behavior