College/university students are at high risk for psychiatric disorder and suicide secondary to age, campus stressors, and social pressures. We therefore report frequencies of 18 Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision disorders and suicidal ideation (SI) acquired anonymously from a Web site receiving 113,181 visits from more than 1,500 predominantly US colleges/universities. Depression was foremost, followed by social phobia and eating disorders. Substance-related disorders were less frequent than expected. SI occurred in 47.1% of students, with women evidencing somewhat stronger findings than men. SI was more associated with substance, bipolar, and panic disorders than depression. Self-reported emotional volatility exceeded thoughts of self-harm for all disorders. The results support two subtypes of suicide risk: dysphoric premeditators and those primarily angry and/or impulsive. Clinicians and researchers should therefore consider suicide as an independent psychopathological phenomenon that includes emotional volatility as a risk factor and thoroughly evaluate psychiatric disorders potentially conferring greater suicidal propensity than depression.