Impaired control over use The person takes the substance in larger amounts or for a longer time than originally planned The person desires to stop or cut down on use of the substance The person spends substantial time obtaining, using, or recovering from the effects of the substance The person has an intense desire (craving) to use the substance Social impairment The person fails to fulfill major role obligations at work, school, or home The person continues to use the substance even though it causes (or worsens) social or interpersonal problems The person gives up or reduces important social, occupational, or recreational activity because of substance use Risky use The person uses the substance in physically hazardous situations (eg, when driving or in dangerous social circumstances) The person continues to use the substance despite knowing it is worsening a medical or psychologic problem Pharmacologic symptoms Tolerance: The person needs to progressively increase the drug dose to produce intoxication or the desired effect, or the effect of a given dose decreases over time Withdrawal: Untoward physical effects occur when the drug is stopped or when it is counteracted by a specific antagonist Note that some drugs, particularly opioids, sedative / hypnotics, and stimulants, can result in tolerance and / or withdrawal symptoms even when taken as prescribed for legitimate medical reasons and for relatively brief periods (< 1 week for opioids).