Addiction is a physical or psychological dependence on a substance or an activity that may be harmful to the addict or can interfere with the addict's normal life.
Many drugs, both illegal and legal, which may include prescription drugs, can cause a physical or psychological dependence. Illicit drug addiction has a negative impact on society as addicts tend to resort to crime to support their addiction. Examples of illegal addictive substances include: cocaine, marijuana, opiates, sedatives and amphetamines. Legal substances that can be addictive include caffeine, alcohol, nicotine, and some prescription medications.
Activities that can become addictive to the point that they interfere with the addict's normal life include: gambling, shopping, exercise, work, computer usage, internet usage, computer games, sex, cleaning and washing.
Cocaine is a commonly used, addictive, illicit drug, obtained from the leaves of the coca plant. Cocaine addiction is characterized by obsessive, compulsive drug consumption that is difficult to stop. Statistically, cocaine addicts that manage to stop their addiction exhibit a high rate of relapse as craving for cocaine remains after stopping use. In addicted users, abrupt stopping of cocaine usage can bring about withdrawal symptoms, such as paranoia, depression, sleep disturbances and anxiety. Cocaine addiction is commonly treated by psychotherapy in rehabilitation centers, but dropout rates in such programs are high. The withdrawal symptoms and the vulnerability to relapse make it difficult to succeed in providing a long-term cure for cocaine addiction.
In many addicts, cue reactivity is exhibited. Cue reactivity is a phenomenon in which an addict physiologically or psychologically responds to a stimulus related to his addiction. In many situations, exposure to a cue associated with an addict's past use of cocaine will elicit and/or increase craving in an addict. For example, for a person addicted to cigarette smoking or a person in a process of breaking an addiction to cigarette smoking, the smell of cigarette smoke or seeing another person light a cigarette may induce craving for a cigarette. For an alcoholic or alcoholic in rehabilitation, the sound of wine glasses clinking may induce a craving for alcohol. For a cocaine addict, seeing drug related paraphernalia may be a cue that induces craving. Cue reactivity may continue for long after the addictive behavior has stopped, increasing a risk that an addict may return to his or her addiction. Many rehabilitation programs encourage addicts to avoid “addiction” cues to facilitate their rehabilitation process.
The effect of polyADP-ribose-polymerase-1 (PARP-1) on long-term memory (LTP) in the sea slug Aplysia [1] and in mammals [2] has been demonstrated.