Substance Abuse vs. Substance Dependence

Substance use disorders are divided into two categories: Substance Abuse and Substance Dependence. Both refer to maladaptive patterns of substance use that lead to significant impairment or distress.

People who abuse substances may:

  • Fail to fulfill major role obligations (e.g., poor work performance or repeated absences from work or school, neglect of children or household)
  • Use substances in situations that are physically hazardous (e.g., driving an automobile or operating machinery when impaired by substance use)
  • Experience substance-related legal problems (e.g., substance-related disorderly conduct, DUI)
  • Continue to use substances despite having persistent or recurrent social or interpersonal problems caused or worsened by the effects of substances (e.g., arguments or physical fights)

People who are dependent upon a substance may experience:

  • Tolerance, which refers to the need to increase amounts of the substance in order to achieve intoxication or the desired effect. A sign of tolerance is a diminished effect with continued use of the same amount of substance.
  • Withdrawal, which is the development of a substance-specific syndrome when substance use is stopped or decreased. The type and length of withdrawal symptoms vary depending upon the substance. A sign of withdrawal is the need to take the same or similar substance in order to avoid withdrawal symptoms.

People who are dependent upon substances may also:

  • Take substances in a larger amount or over a longer period of time
  • Want to cut down or control substance use, but may be unable to do so
  • Spend a lot of time and effort doing whatever is necessary to obtain the substance or recovering from the negative effects of using the substance
  • Give up or reduce social, occupation, or recreational activities because of substance use
  • Continue to use the substance despite awareness of physical or psychological problems that are either caused or worsened by substance use

In summary, people who abuse substances likely experience negative consequences associated with substance use. People who are dependent upon a substance likely experience tolerance or withdrawal, and exhibit a pattern of compulsive substance use.

Self-assessment Tools

Self-assessment tests and screening tools can be the key to identifying, understanding, and getting support for drug and alcohol dependence. These quick and easy tests can be the simple first step toward getting helpful information for you, your family, your friends, and your colleagues.

Substance Use Disorder Consequences

Overdose, physiological reactions (e.g., arrhythmia), nausea, paranoia, poor decision making (e.g., risky sex), risk of injury or death, driving-related accidents, and legal consequences are a few of the immediate consequences of substance use.2 Substance abuse can have negative secondary effects on others, such as family members and fellow service members (e.g., failure to perform responsibilities and interpersonal conflicts related to intoxication). Long term consequences of substance use include: social, financial, and legal problems, neurological impairments, cancer, cardiovascular disease, liver disease, and reproductive disorders. 2

Some people use substances as an ineffective coping strategy for managing other problems. For example, it is not uncommon for people to use substances to cope with deployment-related problems.3 Substance Use Disorders are associated with other disorders, such as Mood Disorders, and Anxiety Disorders, like PTSD. The cost associated with some substances can lead people to engage in criminal activity. Substance use disorders can also be associated with violence and suicide.

  1. American Psychiatric Association (2000). Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision. Washington, DC: American Psychiatric Association.
  2. Marlatt, G.A., & Witkiewitz, K. (in press). Substance Use Disorders. In J. E. Fisher & W. T. O'Dononhue (Eds.), Practice Guidelines for Evidence Based Psychotherapy. New York: Springer Publishing Company.
  3. National Center for PTSD, Walter Reed Army Medical Center (2004). The Iraq War Clinician Guide, 2nd Edition.