Abuse of Quaaludes creates a barbiturate-type dependence. It is highly addictive and frequent users build a tolerance to it, meaning they need to take higher doses to achieve the same euphoric effect. This makes Quaalude use dangerous, increasing the likelihood of an overdose or death. They can also cause withdrawal symptoms similar to barbiturates, which includes:

• restlessness
• irritability
• nausea
• vomiting
• weakness
• headache
• insomnia
• tremors
• mental confusion
• seizures.