A Study of RG7314 to Investigate Efficacy and Safety in Individuals With Autism Spectrum Disorders (ASD)

Inclusion Criteria:

- Participants meet Diagnostic and Statistical Manual of Mental Disorders, Fifth
Edition (DSM-5) criteria for ASD and Tenth Revision of the International
Classification of Diseases and Related Health Problems (ICD-10) criteria for Autism
diagnosis

- SRS-2 (T-score) greater than or equal to (>/=) 66

- CGI-S >/=4 (moderately ill)

- Participants have an Intelligence Quotient (IQ) >/=70 (Wechsler Abbreviated State of
Intelligence)

- A body mass index (BMI) between 18 to 40 kilograms per square meter (kg/m^2)
inclusive

- Language, hearing and vision compatible with the study measurements as judged by the
investigator

- Lives with (or has substantial periods of contact with) a caregiver who is willing
and able to attend visits when required, oversee the participant's compliance with
protocol-specified procedures and study medication dosing, and report on the
participant's status via completion of study assessments. Any period of absence must
be covered by another caregiver. Non-cohabitating caregiver(s) must spend sufficient
time with the participant so that, in the opinion of the investigator, the
caregiver(s) can reliably assess participant's mental status, activities and
behavior.

Exclusion Criteria:

- Alcohol and/or substance abuse/dependence during the last 12 months

- A significant risk for suicidal behavior, in the opinion of the investigator

- Systolic blood pressure greater than (>) 140 or less than (<) 90 millimeters of
mercury (mm Hg), and diastolic blood pressure >90 or less than (<) 50 mm Hg

- Resting pulse rate >90 or <40 beats per minute

- Use of prohibited medications or herbal remedies within 2 weeks prior to
randomization, or 5 half-lives (whichever is longer)

- Initiation of a new major change in psychological intervention within 4 weeks prior
to randomization. Minor changes in ongoing treatment are not considered significant

- Participation in an investigational drug or device study within 60 days prior to
randomization