What are common symptoms of a diazepam overdose?

Sedation, confusion: Sedation, confusion, disorientation, uncoordination, disinhibition, respiratory depression and death.

Oversedation: Initially people look like they are drunk - impaired balance, clumsiness, slurred speech, disinhibited behavior, mood lability (from happy to angry to sad to happy etc.) and ultimately sleep. Benzos rarely cause problems beyond prolonged sleep when taken alone, but aspiration with pneumonia and pressure sores can occur. In severe od, esp with alcohol, progression to coma and death can occur.