A Study to Evaluate the Long-term Safety and Tolerability of KarXT and KarX-EC for the Treatment of Schizophrenia and Autism-Related Irritability in Adolescents, Respectively

Inclusion Criteria \- Participants must have completed the double-blind treatment period (ie, Visit 8) of Study CN0120020 or the double-blind treatment period (ie, Week 8) of Study CN0120044 or CN0120045, without an adverse event (AE) that, in the investigator's opinion, may indicate an unacceptable safety risk. Exclusion Criteria * Participants must not have a significant risk of committing violent acts, serious self-harm, or attempting suicide based on history or routine psychiatric status examination, or those who are homicidal or are considered to be a high risk to others, or who have an answer of "Yes" on Questions 4 or 5 on the suicidal ideation section of the "Since Last Visit" version of the C-SSRS at baseline (Visit 1). Nonsuicidal, self-injurious behavior is not exclusionary. * Participants must not have any clinically significant abnormality including any finding(s) from the physical examination, vital signs, ECG at the end of treatment visit of Study CN0120020, CN0120044, or CN0120045 that the investigator, in consultation with the Sponsor Medical Monitor, would jeopardize the safety of the participant. * Participants must not have either a systolic blood pressure (sBP) or diastolic blood pressure (dBP) meeting criteria for stage 2 hypertension (HTN), regardless of the presence or absence of symptoms. * Other protocol-defined Inclusion/Exclusion criteria apply.