Miu 2016.

Study characteristics
Methods	Study design: RCT Study grouping: parallel group Unit of randomisation: individuals Power (power & sample size calculation, level of power achieved): not specified Imputation of missing data: no imputation of missing data; available‐case analysis (only participants for whom outcomes were obtained at baseline and follow‐up assessment)
Participants	Country: USASetting: laboratory at Emory UniversityAge: age not specified (university students)Sample size (randomised): 123Sex: 81 women, 26 menComorbidity (mean (SD) of respective measures in indicated, if available) at baseline: depressive symptoms (BDI‐II): IG: 8.41, CG: 8.29; many participants with minimal number of depressive symptoms (8.35 (6.89)); considerable number of participants who reported mild depression (20%) and moderate depression (9%) with range of 0 ‐ 31; i.e. no clinical sample, but adequate range of depression symptoms; severe mental disorders (e.g. bipolar disorder, schizophrenia) as exclusion criterion: none of participants met this criterion Population description: university students from psychology department Inclusion criteria: not specified Exclusion criteria: severe mental disorders, such as bipolar disorder and schizophrenia Attrition (withdrawals and exclusions): in total: 16 excluded from analysis: 11 lost to follow‐up (i.e. did not complete follow‐up assessment); 5 excluded Reasons for missing data: for 11 losses to follow‐up: not specified; 1 outlier excluded; 4 excluded due to being non‐freshmen Adverse events: not specified
Interventions	Intervention: mindset intervention (n = 61) delivery: laboratory; not specified if group or individual setting providers: not specified; probably researchers at laboratory (psychology department) at Emory University duration of treatment period and timing: 1 approximately 25‐minute visit/session description: implicit theory about personality (1. read article; 2. read testimonials from others; 3. write to others about what they learned) 1) ARTICLE: participants are taught the changeability mindset about one’s own personality by first presenting a personal anecdote and then scientific article about the potential to change personality article presents studies about how behaviours are controlled by the brain and how brain pathways can be changed (Yeager 2013a; Yeager 2013b), as a way to provide a scientific basis for believing in the potential for change; article emphasises that if participants experience a rejection or failure, the failure is not due to a fixed, personal deficiency on their part; participants are asked to summarise the article to ensure they were actively reading it 2) TESTIMONIALS: afterwards, participants read testimonials from others (i.e. upperclassmen) who used the changeability mindset when they encountered a setback 3) NARRATIVE: participants also asked to write a similar narrative to future student because this narrative exercise has been shown to help participants internalise the intervention material (see Aronson 1999; Walton 2011) compliance: not specified integrity of delivery: not specified economic information: not specified theoretical basis: adapted from the intervention on changeability mindset about bullies’ personality used and described in several previous studies (e.g. Miu 2015; Yeager 2013b) rather than emphasising bullies’ personalities and overt aggression among high school students as in past interventions, the present intervention made the article and situation more relevant to college freshmen by discussing the potential for change in one’s own personality and change in rejection or exclusion in college Control: attention control (n = 62) delivery: laboratory; not specified if group or individual setting providers: not specified; probably researchers at laboratory (psychology department) at Emory University duration of treatment period and timing: 1 approximately 25‐minute visit/session description: the role of brain (1. read article; 2. read testimonials from others; 3. write to others about what they learned) 1) ARTICLE: participants learn about how different brain parts are specialised in different skills and how the brain processes information (see Yeager 2011) 2) TESTIMONIALS: participants read testimonials about how college upperclassmen integrated the article into understanding the new physical environment at Emory (e.g. the occipital lobe controls your vision and eventually it adjusts to the new school environment) 3) NARRATIVES: participants then asked to write a similar narrative to future students about how the brain adjusts to the new physical environment compliance: not specified integrity of delivery: not specified economic information: not specified theoretical basis: not specified
Outcomes	Outcomes collected and reported: depressive symptoms ‐ BDI‐II attributions ‐ ASQ mindsets about personality ‐ IPTQ self‐form Time points measured and reported: 1) pre‐intervention (initial visit); 2) 1‐month follow‐up (2. visit; i.e. 1 month after initial visit; 1 month post‐intervention); 3) participants with complete data at both time points, invited to participate in voluntary 3‐month follow‐up (3. visit; i.e. 3 months after initial visit, 3 months post‐intervention) Adverse events: not specified
Notes	Contact with authors: We contacted the authors for the SDs for the outcomes reported in Table 3, but received no response to 2 inquiries Study start/end date: not specifiedFunding source: not specifiedDeclaration of interest: not specifiedEthical approval needed/obtained for study: not specifiedComments by study authors: not relevant Miscellaneous outcomes by the review authors: dissertationCorrespondence: Adriana S Miu; Advisor: Marshall Duke, PhD; Duke: Department of Psychology; Emory University; psymd@emory.edu; 36 Eagle Row, Emory University, Atlanta, GA 30322; Phone: 404‐727‐7453
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Quote: "After participants completed baseline questionnaires of mindsets, depression, and attributions, within the same session, they were randomly assigned on Qualtrics (Qualtrics, Provo, UT) to either the changeability mindset intervention or the control condition, as detailed below." Quote: "Randomization Check. Randomization of the mindset intervention was effective except for baseline differences in mindsets (see Table 1)." Quote: "There were no significant baseline differences on covariates between participants in intervention and control groups, such as sex (X 2 = 1.96, p =.162), race/ ethnicity (X 2 = 2.53, p =.639), socioeconomic class (X 2 = 5.94, p =.204), grades (t = ‐1.75, p = .084), and locus of control (t = .84, p = .400)." Quote: "Regarding variables of interest, there were no significant baseline differences in depressive symptoms (t = ‐.09, p = .932), and stable attributions (t = .40, p = .687), between treatment and control groups, except for baseline mindset beliefs, t = ‐2.33, p = .022." Quote: "At baseline prior to the intervention, participants who received the intervention had a more changeability mindset (M = 2.95, SD = 1.07) compared to participants who were randomized to the control condition (M = 2.50, SD = .90)." Judgement comment: investigators describe a random component in the sequence‐generation process (Qualtrics software); verified baseline comparability of groups for sociodemographic characteristics (sex, race/ethnicity, socioeconomic class, grades, locus of control; all Ps > 0.16) and most outcome variables (depressive symptoms, stable attributions) except for mindset belief (P = 0.022) with IG having a more changeability mindset compared to CG
Allocation concealment (selection bias)	Unclear risk	Judgement comment: insufficient information about allocation concealment to permit judgement of ‘Low risk’ or ‘High risk’ (method of concealment is not described in sufficient detail)
Blinding of participants and personnel (performance bias) Subjective outcomes	Low risk	Quote: "Research assistants and researchers were blind to condition, as treatment randomization was conducted through Qualtrics." Quote: "a double‐blind randomized mindset intervention was conducted to reduce depressive symptoms one month post‐intervention." Judgement comment: intervention provided in the laboratory (participants in both groups read articles and are asked to write narratives); blinding of participants and intervention providers probably ensured (double‐blind study), and unlikely that the blinding could have been broken
Blinding of outcome assessment (detection bias) Subjective outcomes	Low risk	Judgement comment: blinding of outcome assessment probably ensured, and unlikely that the blinding could have been broken (online surveys; e‐mail/link to online survey provided by researcher; see performance bias: research assistants and researchers were blind to condition)
Incomplete outcome data (attrition bias) All outcomes	High risk	Quote: "Eleven participants did not complete the one‐month follow‐up study and four participants were not freshmen and therefore excluded (see Table 2 for baseline differences between dropouts and full sample)." Judgement comment: reasons for missing data likely to be related to true outcome with imbalance in missing data between groups (61 randomised to IG vs 62 to CG; in total: 16 exclusions (11 lost to follow‐up, 1 outlier, 4 non‐freshmen): IG: 12 exclusions, CG: 4); available‐case analysis (only participants for whom outcomes were obtained at baseline and follow‐up assessment)
Selective reporting (reporting bias)	Low risk	Judgement comment: no study protocol or trial registration available but it is clear that the published reports include all expected outcomes, including those that were prespecified (T3 assessment optional)