An exploratory, double-arm, 8-week study to explore the feasibility and acceptability of abbreviated treatment with CT-156 for people with Schizophrenia.

Inclusion Criteria:

• Willing and able to provide written informed consent to participate in the study, attend study visits, and comply with study-related requirements and assessments.
• Is at least 18 years of age at the time of informed consent.
• Fluent in written and spoken English, confirmed by ability to read and understand the informed consent form.
• Lives in the United States.
• Meets diagnostic criteria for a primary diagnosis of schizophrenia as defined in the ICD-11 or DSM-5 for at least 6 months prior to screening.
• Has outpatient treatment status at the time of screening, with no psychiatric inpatient hospitalization within 13 weeks (3 months) prior to screening.
• Is currently prescribed at least one typical and/or atypical antipsychotic medication and has been on the same antipsychotic medication(s) for at least 13 weeks (3 months) prior to enrollment (Day 1). Dose adjustments are permitted during the study as outlined in the respective package insert(s).
• Has an average domain score ≥2 in at least 2 domains of Understanding and Communicating, Getting Along with People, Life Activities - Household, or Participation in Society on the WHO-DAS 2.0.
• Participant is the only user of an iPhone with iPhone operating system (iOS) version 15 or later or a smartphone with an Android operating system (OS) version 12 or later and agrees to download and use the digital mobile application as required by the protocol.
• Is willing and able to receive short message service (SMS) text messages and push messages on their smartphone.
• Is the owner of or has regular access to an email address.
• Has regular access to the internet via cellular data plan and/or WiFi.
• Has stable housing and has remained at the same residence for at least 13 weeks (3 months) prior to screening and does not anticipate any housing changes for the duration of the study.
• Understands the use of Study App during the Screening Period and at the Baseline Visit, per investigator judgment.

Exclusion Criteria:

• Has positive symptoms of schizophrenia that, in the opinion of the investigator, would preclude effective engagement in the treatment to improve functional impairment.

• Is currently receiving or has received concomitant therapy, defined as individual or group-based structured treatment (e.g., Cognitive Behavioral Therapy, Social Skills Training, Motivational Interviewing, or Vocational/Occupational Therapy), within 3 months (13 weeks) prior to screening per investigator assessment.

• Is currently treated with more than 2 antipsychotic medications (including more than 2 dosage forms).

• Meets ICD-11 or DSM-5 criteria for diagnoses not under investigation that will impact compliance to the protocol, including schizophreniform, schizoaffective, or psychosis non-specific disorders (post-traumatic stress disorder [PTSD], bipolar disorder, major depressive disorder, developmental disorders).

• Meets ICD-11 or DSM-5 criteria for a current episode of depression, mania or hypomania.

• Meets ICD-11 or DSM-5 criteria for a current substance or alcohol use disorder (excluding caffeine and nicotine) that would interfere with compliance to the protocol, per investigator judgment. Diagnoses classified as in sustained remission are permitted.

• In the investigator's opinion, currently needs or will likely require prohibited concomitant medications and/or therapy during the study.

• Is at moderate to high risk for suicide, defined by any of the following:

  1. A "yes" response to either item 4 or 5 on the Columbia-Suicide Severity Rating Scale (C-SSRS) Suicidal Ideation Items within the last 13 weeks (3 months) prior to screening or at Baseline (Day 1)
  2. A "yes" response on the C-SSRS Suicidal Behavior Items within the last 26 weeks (6 months) prior to screening or at Baseline (Day 1)
  3. In the opinion of the investigator, presents a serious risk of suicide

• Has participated in another clinical study (interventional or observational) in the last 13 weeks (3 months).

• Has previously participated in any of the following studies: CT-155-C-001, CT-155-C-002, CT-155-C-003, CT-155-P-00x, CT-155-A-001, CT-155-R- 001, CT-156-D-001, CT-156-C-001, CT-156-P-00x.