This single-center, open-label, cross-over study will evaluate the effect of fluvoxamine on the pharmacokinetics of RO4917523 in healthy volunteers. Healthy volunteers will receive a single dose of RO4917523 alone and in combination with multiple doses of fluvoxamine in a cross-over design. The anticipated time on study treatment is 40 days.

Inclusion Criteria:

• Healthy volunteers, 18-65 years of age inclusive
• Non-smokers
• Body mass index (BMI) between 18 and 30 mg/m2 inclusive
• Women who are not menopausal or surgically sterile agree to use two adequate methods of contraception

Exclusion Criteria:

• Evidence of any active or chronic disease
• History of any significant disease (e.g., cardiovascular, hepatic, renal) or cancer History or presence of clinically significant psychiatric condition
• Any condition or disease that would render the volunteer unsuitable for the study, place the volunteer at undue risk or interfere with the ability of the volunteer to complete the study