The excessive intake of cocaine, can result in physiological damage, lethargy, depression, or a potentially fatal overdose. The immediate craving to use more cocaine is strong and very common, because euphoric effects usually subside in most users within an hour of the last dosage, leading to serial cocaine re-administrations, and prolonged, multi-dose binge use in those who are addicted. When administration stops after binge use, it is followed by a "crash", the onset of severely dysphoric mood with escalating exhaustion until sleep is achieved. Resumption of use may occur upon awakening or may not occur for several days, but the intense euphoria such use can, as it has in many users, produce intense craving and develop rather quickly into addiction. The risk of becoming cocaine-dependent within 2 years of first use (recent-onset) is 5-6%; after 10 years, it's 15-16%. These are the aggregate rates for all types of use considered, i.e., smoking, snorting, injecting. Among recent-onset users, the relative rates are higher for smoking (3.4 times) and much higher for injecting (31 times). They also vary, based on other characteristics, such as gender: among recent-onset users, females are 3.3 times more likely to become addicted, compared to males; age: among recent-onset users, those who started using at ages 12 or 13 were 4 times as likely to become addicted, compared to those who started between ages 18 and 20; and race: among recent-onset users, non-Hispanic Blacks are 7 times as likely to become addicted, compared to non-Hispanic Whites. Many habitual abusers develop a transient manic-like condition similar to amphetamine psychosis and schizophrenia, whose symptoms include aggression, severe paranoia, and tactile hallucinations (including the feeling of insects under the skin, or "coke bugs") during binges. Cocaine has positive reinforcement effects, which refers to the effect that certain stimuli have on behavior. Good feelings become associated with the drug, causing a frequent user to take the drug as a response to bad news or mild depression. This activation strengthens the response that was just made. If the drug was taken by a fast acting route such as injection or inhalation, the response will be the act of taking more cocaine, so the response will be reinforced. Powder cocaine, being a club drug is mostly consumed in the evening and night hours. Because cocaine is a stimulant, a user will often drink large amounts of alcohol during and after usage or smoke cannabis to dull "crash" effects and hasten slumber. Benzodiazepines (e.g., xanax, rohypnol) are also used for this purpose. Other drugs such as heroin and various pharmaceuticals are often used to amplify reinforcement or to minimize such negative effects, further increasing addiction potential and harmfulness. It has been shown in studies that rhesus monkeys provided with a mechanism of cocaine self-administration prefer the drug over food that is in the cage. This happens even when the monkeys are starving. It is speculated that cocaine's addictive properties stem partially from its DAT-blocking effects (in particular, increasing the dopaminergic transmission from ventral tegmental area neurons). However, a study has shown that mice with no dopamine transporters still exhibit the rewarding effects of cocaine administration. Later work demonstrated that a combined DAT/SERT knockout eliminated the rewarding effects. The rewarding effects of cocaine are influenced by circadian rhythms, possibly by involving a set of genes termed "clock genes". However, chronic cocaine addiction is not solely due to cocaine reward. Chronic repeated use is needed to produce cocaine-induced changes in brain reward centers and consequent chronic dysphoria (described above under "Effects and Health Issues - Chronic"). Dysphoria magnifies craving for cocaine because cocaine reward rapidly, albeit transiently, improves mood. This contributes to continued use and a self-perpetuating, worsening condition, since those addicted usually cannot appreciate that long-term effects are opposite those occurring immediately after use.

Treatment
Cognitive Behavioral Therapy (CBT) shows promising results. One or more cocaine vaccines exist or are on trial that will stop desirable effects from the drug. The National Institutes of Health of an unspecified country is researching modafinil, a narcolepsy drug and mild stimulant, as a potential cocaine treatment. Twelve-step programs such as Cocaine Anonymous (modeled on Alcoholics Anonymous) are claimed by many cocaine addicts to be helpful in achieving long-term abstinence. These spiritual programs have no statistically-measurable effect as Alcoholics Anonymous does not release any quantifiable measure of its success rates. There are, however, many recovering addicts who claim this program has aided them.

Studies have shown that gamma vinyl-gamma-aminobutyric acid (gamma vinyl-GABA, or GVG), a drug normally used to treat epilepsy, blocks cocaine's action in the brains of primates. GVG increases the amount of the neurotransmitter GABA in the brain and reduces the level of dopamine in the region of the brain that is thought to be involved in addiction. In January 2005 the U.S. Food and Drug Administration gave permission for a Phase I clinical trial of GVG for the treatment of addiction. Another drug currently tested for anti-addictive properties is the cannabinoid antagonist rimonabant.

Venlafaxine (Effexor), although not a dopamine re-uptake inhibitor, is a serotonin-norepinephrine reuptake inhibitor that has been successfully used to combat the depression caused by cocaine withdrawal and to a lesser extent, the addiction associated with the drug itself. Venlafaxine has been shown to have significant withdrawal problems itself, and can lead to lifetime use due to these withdrawal effects. A statisically significant number of people prescribed Effexor have committed suicide (2 attempts per 1000 patients, vs 1.56 suicides per 1,000 untreated depressives).

 Coca herbal tea has been used for the treatment of cocaine dependence. The effects of the coca tea are a nice stimulation and mood lift. It doesn't produce any significant numbing of the mouth nor does it give a rush like snorting cocaine. Much of the effect of coca seems to come from the secondary alkaloids, as it is not only quantitatively different from pure cocaine but also qualitatively different. In one study, coca tea was used—in addition to counseling—to treat 23 addicted coca-paste smokers in Lima, Peru. Relapses fell from an average of 4.35 times per month before treatment with coca tea to 1.22 during the treatment. Abstinence length increased from an average of 32 days prior to treatment to 217.2 days during treatment. These results suggest that coca tea is an effective method for preventing relapse during treatment for cocaine addiction.