What’s the Difference Between Tolerance and Dependence?

Drug and alcohol abuse is a major public health concern. In 2014, nearly 88% of Americans said they had consumed alcohol at some point, and nearly 680,000 adolescents suffered from an addiction to alcohol.¹ Illegal drug use has also risen in the last decade or so, with an estimated 9.4% of Americans aged 12 and older having reported illicit drug use.² In 2013, there were nearly 3 million new illegal substance users and about 54% of them were adolescents.²

Someone who repeatedly abuses alcohol or drugs may develop both dependence and tolerance to their effects over time. While these two conditions often arise together, there are important differences between them. Understanding those differences can give you a clearer picture of substance abuse and the progressive nature of addiction so you can better recognize when casual use has become problematic and know when it’s time to seek professional help.

Drug and Alcohol Tolerance

Tolerance to a drug occurs when a person doesn’t experience the same high he or she used to get when using the same amount of the drug.³ This happens because the brain has adapted to the presence of the drug. Those with a high tolerance may take more frequent doses than their other using friends, and in greater amounts. They may also begin to mix substances to achieve intoxication more easily. As tolerance builds, the brain’s chemistry alters and adapts further to the repeated exposure, prompting use of an ever-increasing amount of drugs in an attempt to overcome the changes.

Likewise, someone who has developed a tolerance to alcohol won’t feel as drunk or intoxicated by drinking the same amount that he or she usually did. So the person has to have more drinks to feel the desired effects of the alcohol.³ Someone who is tolerant to alcohol may drink more quickly than his or her drinking friends or may consume a higher number of drinks in a night. If most of his or her peers are drinking beer or wine, the tolerant individual may choose hard liquor because of its higher alcohol content. Or the person may suggest taking shots of grain alcohol to speed up the progression to intoxication.

If these behaviors continue, significant changes to the brain cells are likely to occur, leading to the development of dependence and the onset of withdrawal symptoms with cessation of use.

Substance Abuse Dependence

Drug dependence has developed at a point when a person can no longer function normally if he or she has not used the drug.⁴ Drug-dependent people will experience unpleasant (and sometimes very serious) withdrawal symptoms when continued drug use slows or stops.⁴ Withdrawal can motivate relapses in those attempting to quit since, in the moments that the uncomfortable symptoms begin to arise, they will often want to postpone or avoid them at any cost.

Signs and symptoms of drug dependence include:

• Taking repeated doses of the drug in a short period of time.
• Taking the drug to alleviate or prevent withdrawal symptoms.
• Using the drug upon waking up.
• Taking other drugs to ease the discomfort of withdrawal symptoms.
• Strong cravings for the drug.
• Taking the drug at work or school.

Just like a person dependent on drugs, a person is dependent on alcohol if he or she can only function normally if alcohol has been consumed. A dependence on alcohol results in uncomfortable and potentially fatal withdrawal symptoms with cessation of use.³ The withdrawal symptoms often make it difficult for heavy drinkers to quit or cut down on use.

Signs and symptoms of alcohol dependence include:

• Drinking more alcohol than intended or for longer periods of time.
• Having a drink or drinks upon wakening.
• Drinking alcohol to alleviate or prevent withdrawal symptoms.
• Experiencing frequent “blackouts.”
• Strong urges to drink alcohol.
• Drinking at work or school.

Dependence on drugs or alcohol can then facilitate the development of an addiction. An addiction is characterized by continued use despite negative consequences. Addicted people may have problems at home, school, or work caused or exacerbated by use, but are unable to quit compulsive use. They may experience significant physical or psychological consequences due to drug use or drinking—yet drug-seeking behaviors persist. As dependence progresses toward addiction, the user may spend greater amounts of time seeking out the substance, using it, and recovering from a hangover, or comedown.

Treatment Options for Addiction

If you are concerned about your drug or alcohol abuse, you may want to consider getting an addiction assessment. A doctor or mental health or addictions professional can evaluate the scope of your substance abuse and assess for any co-occurring mental health disorders. Below are a few places in which you can be assessed:

• Hospital.
• Treatment center.
• At a therapist’s office.

Detox may be necessary in the event that you have a severe addiction or if you have tried to quit and relapsed before. Withdrawal from alcohol and benzodiazepines (an anti-anxiety medication) can be life-threatening, so detox may provide patients with medication to ease withdrawal symptoms, and 24-hour medical care to ensure safety. Typically, patients complete a short-term detox program, then transition to a longer recovery program.

Various types of treatment programs you may want to explore include:

• Inpatient: Inpatient programs, which require that the person lives at the facility, provide a patient with comprehensive and individualized treatment programs that cater to the patient’s unique needs. Typically, the services available include individual therapy, group counseling, medication-management, family therapy and education, and aftercare planning.
• Outpatient: Outpatient programs, which allow the person the freedom to live at home while recovering from an addiction, are more affordable and flexible options. Patients generally attend group or individual counseling sessions at a recovery center several times a week.
• Support groups: Support groups are usually an integral part of an aftercare program. Once an individual has completed a treatment program, it is wise to follow a relapse prevention plan, usually provided by the treatment team. These groups are free to join and have a supportive and encouraging environment, in which members listen and share their stories related to addiction and recovery.