Development and Testing of a Caregiver-facing Mobile Health Intervention to Reduce Duration of Untreated Psychosis
Phase: NA
Conditions: Caregiver to a Young Adult With Early Psychosis
Sponsor: University of Washington

STUDY PROTOCOL AND STATISTICAL ANALYSIS PLAN 
 
Title: Bolster: Caregiver App to Reduce Duration of Untreated Psychosis 
ClinicalTrials.gov Identifier: NCT04949542 
Principal Investigator: Benjamin Buck, Ph.D. (2021-2025, including active study period) / Dror Ben-
Zeev, Ph.D. (2025, close-out) 
Updated September 26, 2025 
 
 

OVERVIEW 
 
Study Objectives. Caregivers play a critical role in the recovery of young adults with early psychosis. The 
involvement of a supportive caregiver is associated with more rapid and sustained treatment engagement, 
reduced relapse risk, and improved functional outcomes. Family-focused interventions reduce caregiver 
burden and reduce risk of patient relapse, but many caregivers face barriers to access. mHealth interventions 
have shown promise in providing self-guided interventions to individuals that face barriers to services. Our 
team conducted a multi-phase user-centered design and development process to build Bolster, an mHealth 
intervention for caregivers to young people experiencing early psychosis. Bolster is designed to provide 
psychoeducation, communication coaching, and self-care support consistent with principles of family 
psychoeducation, cognitive behavior therapy, and motivational enhancement. The objective of this project is to 
evaluate the acceptability and preliminary effectiveness of Bolster, as well as examine the feasibility of our 
proposed study methods should results warrant future testing in a fully-powered trial. Participants will be sixty 
(N = 60) caregivers randomized (2:1) to either receive a collection of resources on psychosis and caregiving 
from scientific and advocacy organizations (control arm) or the same resources and the Bolster app (active 
intervention or Bolster arm). Participants will complete assessments of outcomes at baseline as well as 6- and 
12-weeks after beginning the intervention. This study aims to evaluate whether Bolster improves caregiver 
knowledge and illness appraisals, reduces distress, improves coping, family communication, and results in 
increased treatment facilitation and treatment received by the affected young adult. 
 
 
Design. This is a parallel group randomized controlled trial design. Participants are randomized 2:1 to receive 
either Bolster (Bolster arm) or control exemplar resources gathered from multiple scientific and advocacy 
organizations. Randomization is stratified based on whether the identified patient had engaged in specialty 
mental health within the past year. Primary outcome assessments are collected remotely with electronic data 
capture at (1) baseline, (2) 6 weeks after app installation, and (3) 12 weeks after app installation. Treatment 
engagement outcomes are reported remotely weekly during the study period. 
 
METHODS 
 
Participants. Participants are 60 individuals (1) aged 18 years or older, who (2) live in the United States, and 
(3) identify as a caregivers to a youth or young adult experiencing early psychosis, wherein this is defined as 
(3a) being between the ages of 15 and 35, who (3b) within the last five years started experiencing symptoms 
meeting the following criteria: (3c) A positive screen according to the Caregiver Prime Screen - Revised 
(endorsed two or more responses of five or six ("somewhat"/"definitely" agree), as well as (3d) “hallmark 
symptoms” including (3d.1) the presence of psychotic symptoms represented by one or more of hallucinations, 
delusions, marked thought disorder, psychomotor disorder or bizarre behavior, as well as (3d.2) definite 
change of personality or behavior manifesting as two or more of the following: serious deterioration of function, 
marked social withdrawal, persistent self-neglect, episodic marked anxiety. The affected person must also be 
(4) not enrolled in specialty mental health services (i.e. a program wherein the affected person can access both 
psychiatry and counseling/therapy services) and has not been enrolled in such services for at least three 
months prior to screening. If an affected person is receiving one of these services, the caregiver reports that 
this is an inadequate level of care. Participants are also required to (5) own an Apple iPhone. Participants are 
excluded they or their loved one is (1) incarcerated or living in a long-term care setting, (2) they failed to 
demonstrate understanding of study details in comprehension screening, or (3) the loved one is not enrolled in 
services only because they previously completed or “graduated” from a specialty treatment program for 
psychosis. 
 
Recruitment. Participants are recruited through online study ads (i.e. Google, Instagram, and YouTube) as 
well as distribution through mental health advocacy organization and treatment websites and listservs. All 
screeners and study questionnaires are completed through online data capture (i.e. REDCap). Once 
participants click a link to the study landing page from a recruitment ad or posting, they are required to 
demonstrate understanding of study details through a comprehension questionnaire, provide informed consent 
and are subject to a series of steps to ensure eligibility for the study and identity verification. Study team 
members evaluate screening data and conduct confirmatory synchronous screening by phone. The invitation 
to complete the baseline assessment is sent to participants after eligibility confirmation via text message. After 

baseline is complete, participants are invited to asked to complete an installation session wherein they are 
introduced to their intervention, and oriented to study details. Participants are randomized to condition (via a 
pre-set stratified randomization algorithm, see above) at the time of the installation session. Once participants 
have installed and been oriented to either the study app and online resources or online resources only, 
members of the study team are available to answer questions about study interventions or respond to 
concerns about the study. Up to three times during the study period, participants in the Bolster arm receive 
outreach via text message and phone call if they stopped using the app for five consecutive days (confirmed 
via app usage logs). This outreach assesses for technical issues or concerns from participants about app use. 
To match this outreach in the Bolster arm, all participants in the control arm receive two phone calls during 
their time in the study, once in the third week and once in the ninth week. Subsequent assessments are sent to 
participants via text messages 6 and 12 weeks after their installation session. Participants are compensated 
with $60 gift cards for completing each assessment battery (or, in the case of baseline, baseline and 
installation session both).  
 
Interventions. Bolster is a self-guided iOS mobile app designed to provide self-guided support to caregivers to 
youth and young people experiencing early psychosis. It combines video, audio, and written text, and draws on 
principles of family psychoeducation, cognitive behavior therapy and motivational enhancement. Participants in 
both arms will be provided support resources from mental health advocacy organizations representing 
currently available resources for caregivers (including a selection from the National Alliance on Mental Illness 
and Mental Health America). They will also have access to the research team by phone for technical 
troubleshooting and support as necessary. 
 
Outcome Measures. Primary and secondary registered measures are listed below. 
 
Measure 
Construct 
Description 
Time Frame 
Family 
Questionnaire 
(FQ) 
Change in Family 
Communication 
Family communication will be assessed 
with the Family Questionnaire (FQ). The 
FQ is a 20-item self-report assessment of 
criticism and emotional expression in 
interactions with family members toward 
patients with mental illness. Each item is 
rated on a 4-point scale (1 = never/very 
rarely; 4 = very often). The FQ is scored 
by summing individual items with higher 
scores indicating greater levels of 
expressed emotion. As a primary 
outcome, we will examine the combined 
total of emotional overinvolvement and 
critical comments; scores range from 20 
to 80 with higher scores indicating greater 
expressed emotion. 
Baseline, 6 
weeks, 12 weeks 
Measure to 
Assess Steps to 
Services, 
Caregivers Edition 
(MASS-CG) 
Change in Treatment 
Facilitation 
Treatment seeking will be measured 
using the Measure to Assess Steps to 
Service-Caregivers (MASS-CG). The 
MASS-CG is a 23-item self-report 
assessment of steps taken by the 
caregiver towards the attainment of 
mental health treatment for their loved 
one, including research, social support, 
encouragement or support of the loved 
one's help-seeking actions, and 
engagement with service provider steps. 
Each item is endorsed on a three-point 
Likert scale (0 = No, I have not done this, 
1 = I have done this once or twice, 2 = I 
have done this multiple times). The 
Baseline, 6 
weeks, 12 weeks 

MASS-CG is scored by summing 
individual items with higher scores 
indicating greater levels of treatment 
facilitation activities. 
Report of 
Treatment 
Engagement, 
Medication 
Provider 
Change in Treatment 
Engagement, 
Medication Provider 
Treatment facilitation / duration of 
untreated psychosis will be assessed 
according to participants' report of 
appointments attended by their relative in 
the past during the treatment period. This 
first category includes meeting with a 
clinician providing psychiatric 
medications. At screening, participants 
report treatment engagement over the 
previous three months and during the 
study period, participants are asked to 
report on this weekly. 
Baseline, 12 
weeks 
Report of 
Treatment 
Engagement, 
Therapy or 
Counseling 
Change in Treatment 
Engagement, Therapy 
or Counseling 
Treatment facilitation / duration of 
untreated psychosis will be assessed 
according to participants' report of 
appointments attended by their relative in 
the past during the treatment period. This 
first category includes meeting with a 
clinician providing mental health therapy 
or counseling. At screening, participants 
report treatment engagement over the 
previous three months and during the 
study period, participants are asked to 
report on this weekly. 
Baseline, 12 
weeks 
Knowledge About 
Schizophrenia 
Test (KAST) 
Change in Illness 
Knowledge, Factual 
Knowledge 
This is assessed with the Knowledge 
About Schizophrenia (KAST), an 18-item 
multiple-choice assessment examining 
individuals' knowledge of the etiology, 
symptoms, and prognosis of 
schizophrenia. Total scores indicate the 
number of correct responses and thus 
range from 0 to 18. 
Baseline, 6 
weeks, 12 weeks 
Illness Perception 
Questionnaire for 
Schizophrenia 
Relatives 
(IPQSR), 
Coherence 
Change in Illness 
Knowledge, Caregiver 
Self-rated 
Illness appraisals will be assessed with 
the Illness Perception Questionnaire for 
Schizophrenia Relatives (IPQSR), a self-
report scale of caregivers' beliefs about 
the severity, prognosis, and 
responsiveness to treatment of mental 
illnesses. Each item is rated on a 5-point 
scale (1 = strongly disagree; 5 = strongly 
agree), and totals are scored by summing 
individual items. For the coherence total, 
we are totaling the 5 items related to the 
caregiver’s report of how much they 
understand or know about their loved 
one’s illness. Scores range from 5 to 25 
with lower scores indicating better self-
rated understanding or coherence. 
Baseline, 6 
weeks, 12 weeks 
Illness Perception 
Questionnaire for 
Schizophrenia 
Relatives 
Change in Illness 
Appraisals, 
Consequences 
Illness appraisals will be assessed with 
the Illness Perception Questionnaire for 
Schizophrenia Relatives (IPQSR), a self-
report scale of caregivers' beliefs about 
Baseline, 6 
weeks, 12 weeks 

(IPQSR), 
Consequences 
the severity, prognosis, and 
responsiveness to treatment of mental 
illnesses. Each item is rated on a 5-point 
scale (1 = strongly disagree; 5 = strongly 
agree), and totals are scored by summing 
individual items. For the consequences 
total, we are totaling the 20 items related 
to consequences affecting the caregiver 
and the affected person. Scores range 
from 20 to 100 with higher scores 
indicating greater perceptions of negative 
consequences. 
Illness Perception 
Questionnaire for 
Schizophrenia 
Relatives 
(IPQSR), Control 
Change in Illness 
Appraisals, Control 
Illness appraisals will be assessed with 
the Illness Perception Questionnaire for 
Schizophrenia Relatives (IPQSR), a self-
report scale of caregivers' beliefs about 
the severity, prognosis, and 
responsiveness to treatment of mental 
illnesses. Each item is rated on a 5-point 
scale (1 = strongly disagree; 5 = strongly 
agree), and totals are scored by summing 
individual items. For the control total, we 
are totaling the 8 items related to 
caregiver, affected person, and treatment 
control over illness course. Scores range 
from 8 to 40 with higher scores indicating 
greater perceptions of possibilities for 
actions that affect the course of illness. 
Baseline, 6 
weeks, 12 weeks 
Illness Perception 
Questionnaire for 
Schizophrenia 
Relatives 
(IPQSR), 
Emotional Distress 
About Illness 
Change in Illness 
Appraisals, Emotional 
Distress About Illness 
Illness appraisals will be assessed with 
the Illness Perception Questionnaire for 
Schizophrenia Relatives (IPQSR), a self-
report scale of caregivers' beliefs about 
the severity, prognosis, and 
responsiveness to treatment of mental 
illnesses. Each item is rated on a 5-point 
scale (1 = strongly disagree; 5 = strongly 
agree), and totals are scored by summing 
individual items. For the emotional 
distress score, we are examining the 
emotional representation scale, a 9-item 
scale with scores ranging from 9 to 45, 
with higher scores indicating greater 
emotional distress. 
Baseline, 6 
weeks, 12 weeks 
Brief Experience 
of Caregiving 
Inventory (BECI) 
Change in Appraisal 
of Caregiving 
Experiences 
Appraisals of caregiving experiences will 
be assessed with the Brief Experience of 
Caregiving Inventory (BECI). The BECI is 
a 19-item assessment of the impact of 
caregiving on the individual's life, both in 
negative and positive ways. The items are 
rated on a 5-point Likert scale (never to 
nearly always), and scores range from 0 
to 76, with a higher score denoting more 
negative appraisals of one’s caregiving 
experience. 
Baseline, 6 
weeks, 12 weeks 
Brief COPE 
Inventory 
Change in Caregiver 
Coping, Activities 
Caregiver coping will be assessed with 
the Brief COPE Inventory, a 28-item self-
Baseline, 6 
weeks, 12 weeks 

report scale of coping skills in response to 
stressors, based on the full COPE 
inventory; items generate a range of 
subscale scores related to specific coping 
areas. The instrument consists of 28 
items which will be scored on a 1 to 4 
Likert scale (I haven’t been doing this at 
all to I’ve been doing this a lot), with 
higher values representing a greater 
frequency of engaging in each coping 
strategy. For this outcome, we will 
examine total frequency sum of items (14) 
assessing variables a priori selected to 
represent adaptive coping. Scores on this 
scale range from 14 to 56. 
Coping Self-
Efficacy Scale 
(CSES) 
Change in Caregiver 
Coping, Self-efficacy 
Caregiver coping self-efficacy will be 
assessed with the Coping Self-Efficacy 
Scale, a 26-item self-report questionnaire 
measuring the perceived ability of coping 
with various life challenges. Responses 
are rated on a 0 to 10 scale, and scores 
range from 0 to 260, with higher scores 
denoting a greater sense of self-efficacy 
in coping. 
Baseline, 6 
weeks, 12 weeks 
General Health 
Questionnaire, 12 
Item Version 
(GHQ-12) 
Change in Caregiver 
Distress 
Caregiver distress (secondary mediator) 
will be assessed with General Health 
Questionnaire (GHQ), a 12-item 
questionnaire assessing general 
psychological morbidity. Respondents 
indicate agreement on a four-point scale 
(0 = Not at all; 3 = More than usual) and 
total scores ranging from 0 to 36 with 
higher scores indicating more severe 
psychological morbidity. 
Baseline, 6 
weeks, 12 weeks 
 
 
DATA ANALYTIC PLAN 
 
Clinical-trial data analyses. Linear regression will be used for continuous outcomes with treatment condition 
and baseline values entered as covariates. We will separately model outcomes at 6 weeks and 12 weeks 
respectively. Participants with missing follow-up data will be included using multiple imputation to reduce bias 
in effect estimates. Within-condition changes will be modeled using linear regression with assessment and 
value at baseline as independent variables. For zero-inflated count outcomes, hurdle models will be used to 
compare treatment conditions on (1) the probability of having such encounters during the 12-week follow-up 
period (binary model, fit using modified Poisson regression to obtain aRR estimates) and the number of weeks 
with such encounters among those with one or more encounters (count model, fit using negative-binomial 
regression to obtain adjusted incidence rate ratio [aIRR] estimates), with offset terms for the natural logarithm 
of the number of weeks surveys were completed. Models will use a two-tailed alpha level of 0.05 to detect 
significant differences between Bolster and control, with patterns of effect sizes and 95% confidence intervals 
(CIs) examined for all outcomes to inform future trials. As this is a pilot trial, conclusions will involve 
interpretations of overall effect sizes.