Addiction is a state in which an individual feels compelled to engage in compulsive behavior to gain a reward, even though there are negative consequences. The rewarding stimuli may be a type of drug or a particular behavior, such as gambling or sex. All addictive stimuli are both reinforcing (increasing the chances that a person will come back again and again) and intrinsically rewarding (considered very desirable).

Examples of common drug and behavioral addictions include the following: opioid addiction, amphetamine addiction, nicotine addiction, alcoholism, cocaine addiction, food addiction, gambling addiction, sex addiction and exercise addiction.

When a person is continuously exposed to an addictive substance or a behavior, the brain’s reward system is drastically altered. The addictive drug or behavior becomes the individual’s top priority and nothing else in life feels as good, even a favorite food or a fun activity that the person previously enjoyed.

The desire for the addictive stimuli is often intense. This causes the addicted individual to seek short-term gratification with less thought toward long-term effects.

In drug addiction, the individual will eventually build a tolerance, causing the drug to feel less effective. This prompts the person to take more of the drug to reach the same high. This can lead to dangerous overdose and death.

If the drug is suddenly stopped, the individual suffers from physical and psychological withdrawal. This is often a terrible ordeal in which the brain and body — having become used to working around the substance — is suddenly forced to figure out how to function without it. Depending on the drug, its strength and length of time used, withdrawals can last from several days to a few months.

Physical withdrawal symptoms may involve trembling, sweating, anxiety, depression, confusion, a feeling of wanting to “jump out of your skin,” restless leg syndrome and overwhelming cravings for the substance.

With behavioral addiction, the individual can also suffer withdrawal, but it is psychological rather than physical. For example, suddenly stopping a gambling addiction may cause temporary feelings of depression and emptiness but will not result in the dangerous physical withdrawals of a drug.

Example: Gary sought treatment for his gambling addiction after he wasted away his family’s savings in casinos.