The primary objective of this study is to determine whether aspirin is effective in alleviating symptoms of the clinical high risk (CHR) syndrome for psychosis. The investigators further aim to determine whether it may delay or prevent the onset of psychosis in those currently experiencing CHR symptoms. As secondary measures the investigators aim to collect laboratory studies of inflammation markers and genetic samples to determine whether certain genetic profiles correlate with risk for psychosis, or response to aspirin treatment.

Patients will be randomly assigned to either active treatment (aspirin) or placebo.

Inclusion Criteria:

• Age 19 - 35
• Must have a SIPS interview
• CHR subjects must meet at least one of 3 CHR syndromes defined by SIPS
• Must demonstrate adequate decisional capacity

Exclusion Criteria:

• Under age of 19
• Have pre-existing gastrointestinal disease, heart disease
• Have kidney disease
• Taking non-steroidal anti-inflammatory medications
• Hypersensitive to NSAID (non-steroidal anti-inflammatory medications)
• Have coexisting unstable major medical illness
• Are pregnant or breastfeeding
• Consume more than 2 drinks of alcohol per day
• Have a blood clotting disorder
• Are taking ACE inhibitors, acetazolamide, anticoagulants, anticonvulsants, beta blockers, diuretics, methotrexate, oral hypoglycemic or uricosuric agents
• Have a history of substance abuse in past three moths or dependence in past 6 months