Difference between Substance Abuse and Substance Dependence

Substance Abuse and Substance Dependence, these two terms are used interchangeably, but they refer to different situations and have a different meaning as described below:

Substance Abuse:

Substance abuse refers to the use of a substance or drug in amounts or with methods neither approved nor supervised by authorized medical professionals. It is the misuse of a drug beyond its intended purpose and prescription, including the use of illegal drugs. So, if a person is taking drugs without consulting a doctor or against the guidelines and policies related to the use of the drug, it is called substance abuse. The most common reason for this abuse is the desire to get a certain feeling or sensation. According to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), the following signs may indicate that a person is abusing drugs:

Involved in illegal activities
High risk-taking behavior
Interpersonal problems
Loss of interest in daily activities

Substance Dependence:

It refers to a condition when the body or brain?s neurons of a person adapt to repeated drug exposure and only function normally under the influence of that drug. In this situation, a person experiences a strong physical or psychological need for a substance to the extent that he experiences withdrawal symptoms when stops using the drug. The body or mind of such people largely depends on the drug, which they are using, to function in a normal manner. It is natural that substance abuse may lead to substance dependence, but the two conditions are not identical. The people suffering from substance dependence may:

Develop a tolerance to the substance so they need more quantity of that substance to produce the same effect
Experience physical withdrawal symptoms like nausea, vomiting, chills, sweating when they stop using the drug
Experience psychological symptoms like anxiety, depression, and irritation when not getting the drug on time
Attempt to quit the drug but fail repeatedly

Thus, based on the above information the key differences between substance abuse and substance dependence may include the following points:

Substance Abuse	Substance Dependence
It is an inappropriate use of a drug, e.g. without a doctor's prescription.	It is similar to addiction to drugs.
A small amount is enough to produce the desired effect or high.	More amounts are needed to produce the same effect.
No strong urge or compulsion to continue the use of drug.	Strong desire or compulsion is experienced to continue using the drug
Mild desire to use the drug to get the desired effect	It becomes body's physiological need (strong urge is felt) to use the drug.
It is mainly physical craving for the drug.	It involves an emotional and psychological craving for the drug.
It is easy to stop abusing drugs on your own.	It is hard to get rid of drug dependence on your own.
One may experience mild withdrawal symptoms.	One usually experiences severe withdrawal symptoms like nausea, depression, muscle aches etc.
Brain cells don't adapt to the repeated use of the drug.	Body and brain cells adapt to the repeated use of the drug and function normally only after consuming the drug.
Drug abuse results in drug dependence	Drug dependence results in drug addiction