Most research has focused on adult population or on college students, but little is known about epidemiology of behavioral addictions in adolescence. A study conducted by Villella "et al" looked at a group of students and the prevalence of various addictions. His results showed exercise addiction was the second most prevalent, after compulsive buying.

High risk groups that appear to be addicted to exercise include athletes in sports encouraging thinness or appearance standards, young and middle-age women, and young men.

In Europe, the rate of problem gambling is typically 0.5 to 3 percent. The "British Gambling Prevalence Survey 2007", conducted by the United Kingdom Gambling Commission, found approximately 0.6 percent of the adult population had problem gambling issues—the same percentage as in 1999. The highest prevalence of problem gambling was found among those who participated in spread betting (14.7%), fixed odds betting terminals (11.2%) and betting exchanges (9.8%). In Norway, a December 2007 study showed the amount of present problem gamblers was 0.7 percent.

The rate of people who have problems of shopping addiction is a very controversial matter, because the dividing line between pathological behaviours and those behaviours which, even if excessive, are socially accepted, is very difficult to determine. However, shopping addiction and other manifestations of the lack of self-control on spending are widespread problems which are constantly expanding. Studies using samples of the general population show that between 8% and 16% of the people have problems with excessive or uncontrolled purchases. Clinical studies give much lower figures, however, between 2% and 5%. According to the European Report on the programme for the prevention and treatment of personal problems related to consumer addiction, personal purchasing habits and over-indebtedness, 3% of European adults and 8% of European young people have a level of shopping addiction which could be considered as pathologic, that is, which seriously affects the life of the people who suffer from this. Other estimates for the prevalence of compulsive buying range from a low of 2 percent to 12 percent or more (in the U.S. population.

Most of people who have these problems neither receive nor ask for treatment. Those that ask for help only do it after years of suffering, when the addiction has caused very serious economic repercussion and has harmed the relationship with their family and social environment. For this reason and due to the lack of social consciousness about this problem, the unrecorded figure of people who suffer from these problems is very high. In addition to the severe cases of shopping addiction, an important part of consumers (between 30% and 50% of the population) have deficiencies with spending self-control or excessive purchases. According to the European Report, 33% of European adults and 46% of the European young people have minor or moderate problems with shopping addiction or lack of economic self-control.

In the United States, the percentage of pathological gamblers was 0.6 percent, and the percentage of problem gamblers was 2.3 percent in 2008. Studies commissioned by the National Gambling Impact Study Commission Act has shown the prevalence rate ranges from 0.1 percent to 0.6 percent. Nevada has the highest percentage of pathological gambling; a 2002 report estimated 2.2 to 3.6 percent of Nevada residents over the age of 18 could be called problem gamblers. Also, 2.7 to 4.3 percent could be called probable pathological gamblers.

According to a 1997 meta-analysis by Harvard Medical School's division on addictions, 1.1 percent of the adult population of the United States and Canada could be called pathological gamblers. A 1996 study estimated 1.2 to 1.9 percent of adults in Canada were pathological. In Ontario, a 2006 report showed 2.6 percent of residents experienced "moderate gambling problems" and 0.8 percent had "severe gambling problems". In Quebec, an estimated 0.8 percent of the adult population were pathological gamblers in 2002. Although most who gamble do so without harm, approximately 6 million American adults are addicted to gambling.

Signs of a gambling problem include:

- Using income or savings to gamble while letting bills go unpaid

- Repeated, unsuccessful attempts to stop gambling

- Chasing losses

- Losing sleep over thoughts of gambling

- Arguing with friends or family about gambling behavior

- Feeling depressed or suicidal because of gambling losses

The consequences of oniomania, which may persist long after a spree, can be devastating, with marriages, long-term relationships, and jobs all feeling the strain. Further problems can include ruined credit history, theft or defalcation of money, defaulted loans, general financial trouble and in some cases bankruptcy or extreme debt, as well as anxiety and a sense of life spiraling out of control. The resulting stress can lead to physical health problems and ruined relationships, or even suicide.

Kimberly Young indicates that previous research links internet/computer addiction with existing mental health issues, most notably depression. She states that computer addiction has significant effects socially such as low self-esteem, psychologically and occupationally which led many subjects to academic failure.

According to a Korean study on internet/computer addiction, pathological use of the internet results in negative life impacts such as job loss, marriage breakdown, financial debt, and academic failure. 70% of internet users in Korea are reported to play online games, 18% of which are diagnosed as game addicts which relates to internet/computer addiction. The authors of the article conducted a study using Kimberly Young's questionnaire. The study showed that the majority of those who met the requirements of internet/computer addiction suffered from interpersonal difficulties and stress and that those addicted to online games specifically responded that they hoped to avoid reality.

Research carried out on people undergoing treatment, as well as on the general population has revealed a negative correlation between age and addiction. As the age of people increases there is a lower number of shopping addicts. This data was confirmed by the 1999 European Report.

It must be noted that the age of diagnosis is much later than the age when the problems of addiction begin. Most addicts have the first symptoms of addiction in their twenties, but do not ask for help nor accept treatment until more than ten years afterwards. To explain the higher incidence of shopping addiction in young people, it has been shown that younger people have been born, and have grown up, in an increasingly consumerist society and they have endured the impact of publicity and marketing from birth. On the contrary, it is very unusual to find shopping addiction problems in people older than 65 years.

Individuals with exercise addiction may put exercise above family and friends, work, injuries, and other social activities. If not identified and treated, an exercise addiction may lead to a significant decline in one's health.

Exercise provides benefits for our bodies, but to some people, the benefits turn into health hazards. To some exercisers, rigorous physical activity becomes the central aspect of their lives. When a preoccupation with exercise has become routine, a person is considered addicted to exercise or exercise dependent. A study done shows why people may become addicted to exercise, especially running. One of the reasons people become addicted to exercise is because of the release of mood-enhancing chemicals known as endorphins. Endorphins increase the sensation of pleasure, which is why people feel good about themselves after they exercise. Endorphins are also responsible for the "runner's high." Recent studies have lent weight to the alternative theory that the addictive appeal of exercise is due to the production of endocannabinoids, naturally produced chemicals that bind to the brain's CB1 receptor, rather than to endorphin production. Those who suffer from exercise addiction will go through physical and emotional withdrawals in the absence of exercise, just like a person who is addicted to other substances, such as drugs or alcohol. Although in many cases, running is a better alternative than substance abuse. The findings in this study conclude that there is a link between negative addiction to running and interpersonal difficulties, which is common in other addictive behaviors as well.

Another form of behavior that is still being investigated is obsessive sun tanning as a behavioral addiction. In a recent study, researchers have proved that many frequent tanners demonstrate signs and symptoms adapted from substance abuse or dependence criteria. Many people who admit to being frequent tanners say they tan to look good, feel good, and to relax. People who partake in excessive tanning are usually completely aware of the health risks associated with it, just like addicted smokers are completely aware of the health risks of smoking. The health hazards are even more severe for high-risk age groups such as teenagers and young adults. Due to the fact that the health risks do not deter tanners from their habit, they are exhibiting self-destructive behavior that resembles the characteristics of those who suffer from substance abuse.

Frequent tanners have said a primary reason why they participate in artificial tanning is to experience the "feel good" feeling tanning salons have to offer. Researchers have found that ultraviolet (UV) radiation from tanning beds offers mood-enhancing effects that act as a treatment for seasonal affective disorder (SAD). SAD is when a person exhibits minor depression during seasonal changes, such as during the winter months. Ultraviolet radiation has been proven to increase the level of melatonin in the body. Melatonin plays a key role in sleep patterns and is suggested to reduce anxiety levels. Thus, those who go tanning experience a sense of relaxation afterwards. This sensation is what possibly drives tanners to continue tanning regardless of the health risks. More research needs to be done, but many researchers are beginning to add tanning to the list of addictive processes.

Diagnostic criteria for compulsive buying have been proposed: 1. Over-preoccupation with buying; 2. distress or impairment as a result of the activity; 3. compulsive buying is not limited to hypomanic or manic episodes.

While initially triggered by a perhaps mild need to feel special, the failure of compulsive shopping to actually meet such needs may lead to a vicious cycle of escalation, with sufferers experiencing the highs and lows associated with other addictions. The 'high' of the purchasing may be followed by a sense of disappointment, and of guilt, precipitating a further cycle of impulse buying. With the now addicted person increasingly feeling negative emotions like anger and stress, they may attempt to self-medicate through further purchases, followed again by regret or depression once they return home - leading to an urge for yet another spree.

As debt grows, the compulsive shopping may become a more secretive act. At the point where bought goods are hidden or destroyed, because the person concerned feels so ashamed of their addiction, the price of the addiction in mental, financial and emotional terms becomes even higher.

Excessive computer use may result in, or occur with:

- Lack of face to face social interaction

- Computer vision syndrome

Complications of late Parkinson's disease may include a range of impulse-control disorders, including eating, buying, compulsive gambling and sexual behavior. One study found that 13.6% of Parkinson's patients exhibited at least one form of ICD. There is a significant co-occurrence of pathological gambling and personality disorder, and is suggested to be caused partly by their common "genetic vulnerability". The degree of heritability to ICD is similar to other psychiatric disorders including substance abuse disorder. There has also been found a genetic factor to the development of ICD just as there is for substance abuse disorder. The risk for subclinical PG in a population is accounted for by the risk of alcohol dependence by about 12-20% genetic and 3-8% environmental factors. There is a high rate of comorbidity between ADHD and other impulse-control disorders.

Over the past decade, the concept of Internet addiction has grown in terms of acceptance as a legitimate clinical disorder often requiring treatment. Researchers are divided over whether Internet addiction is a disorder on its own or a symptom of another underlying disorder. There is also debate over whether it should be classified as an impulse-control disorder or an obsessive-compulsive disorder rather than an addiction.

While the existence of Internet addiction is debated, self-proclaimed sufferers are resorting to the courts for redress. In one American case ("Pacenza v. IBM Corp."), the plaintiff argued he was illegally dismissed from his employment in violation of the Americans with Disabilities Act because of Internet addiction triggered by Vietnam War-related post-traumatic stress disorder (PTSD). The case was dismissed by the United States District Court for the Southern District of New York and affirmed on appeal to the United States Court of Appeals, Second Circuit in 2010 (case summarized in Glaser & Carroll, 2007).

About 25% of users fulfill Internet addiction criteria within the first six months of using the Internet. Many individuals initially report feeling intimidated by the computer but gradually feel a sense of "competency and exhilaration from mastering the technology and learning to navigate the applications quickly by visual stimulation" (Beard 374). The feeling of exhilaration can be explained by the way IAD sufferers often describe themselves as: bold, outgoing, open-minded, intellectually prideful, and assertive.

According to a study by Kathy Scherer, a psychologist from the University of Texas at Austin, "13% of college internet users fit the criteria for Internet addicts" (Scherer 1997). In her study, Scherer enlisted the help of 531 college students. She discovered that "72% of the Internet addicted students were men" (Scherer 1997).

The China Communist Youth League claimed in 2007 that over 17% of Chinese citizens between 13 and 17 were addicted to the Internet.

Public concern, interest in, and the study of, Internet over use can be attributed to the fact that it has become increasingly difficult to distinguish between the online and offline worlds. The Internet has tremendous potential to affect the emotions of humans and in turn, alter our self-perception and anxiety levels.

According to Maressa Orzack, director of the Computer Addiction Study at Harvard University's McLean Hospital, between 5% and 10% of Web surfers suffer some form of Web dependency.

According to the Center for Internet Addiction Recovery (whose director is Kimberly S. Young, a researcher who has lobbied for the recognition of net abuse as a distinct clinical disorder), "Internet addicts suffer from emotional problems such as depression and anxiety-related disorders and often use the fantasy world of the Internet to psychologically escape unpleasant feelings or stressful situations." More than half are also addicted to alcohol, drugs, tobacco, or sex.

Mark Griffiths states that "[t]he way of determining whether nonchemical (i.e., behavioral) addictions are addictive in a nonmetaphorical sense is to compare them against clinical criteria for other established drug-ingested addictions", and although his data is dated, and may no longer represent average Internet use accurately, Griffiths comes to the conclusion that the Internet does meet that criteria for addiction in a small number of users.

Scientists have found that compulsive Internet use can produce morphological changes in the structure of the brain. A study which analyzed Chinese college students who had been classified as computer addicts by the study designers and who used a computer around 10 hours a day, 6 days a week, found reductions in the sizes of the dorsolateral prefrontal cortex, rostral anterior cingulate cortex, supplementary motor area and parts of the cerebellum compared to students deemed "not addicted" by the designers. It has been theorized that these changes reflect learning-type cognitive optimizations for using computers more efficiently, but also impaired short-term memory and decision-making abilities—including ones in which may contribute to the desire to stay online instead of be in the real world.

Patricia Wallace PhD, Senior Director, Information Technology and CTY Online, at the Johns Hopkins University Center for Talented Youth argues that based on the case histories that have surfaced, no one denies that excessive involvement with certain psychological spaces on the net can have serious effects on a person's life. She explains that, at a large university in New York, the dropout rate among freshmen newcomers rose dramatically as their investment in computers and Internet access increased, and the administrators learned that 43% of the dropouts were staying up all night on the Internet.

Internet addiction disorder, more commonly called problematic Internet use (PIU), refers to excessive Internet use that interferes with daily life.

Kleptomania is frequently thought of as being a part of obsessive-compulsive disorder (OCD), since the irresistible and uncontrollable actions are similar to the frequently excessive, unnecessary, and unwanted rituals of OCD. Some individuals with kleptomania demonstrate hoarding symptoms that resemble those with OCD.

Prevalence rates between the two disorders do not demonstrate a strong relationship. Studies examining the comorbidity of OCD in subjects with kleptomania have inconsistent results, with some showing a relatively high co-occurrence (45%-60%) while others demonstrate low rates (0%-6.5%). Similarly, when rates of kleptomania have been examined in subjects with OCD, a relatively low co-occurrence was found (2.2%-5.9%).

Kleptomania is characterized by an impulsive urge to steal purely for the sake of gratification.

In the U.S. the presence of kleptomania is unknown but has been estimated at 6 per 1000 individuals. Kleptomania is also thought to be the cause of 5% of annual shoplifting in the U.S. If true, 100,000 arrests are made in the U.S. annually due to kleptomaniac behavior.

Not only are there significant health risks associated with compulsive hoarding, but scientists are also trying to pinpoint how significant the interference is with occupational and social functioning in a hoarder's daily life. In a pool of compulsive hoarders, 42% found their behavior problematic to the 63% of their family and friends who saw the behavior as problematic. The findings suggest that individuals who hoard may exhibit impaired sensitivity to their own and others’ emotions, and conversely, relate the world around them by forming attachments to possessions rather than to people. Lower emotional intelligence among hoarding patients may also impact their ability to discard and organize their possessions. With such detrimental characteristics, comprehensive research has been performed to find a cure. Although this is ongoing research, most investigations have found that only a third of patients who hoard show an adequate response to these medications and therapeutic interventions.

With the modifications to the DSM, insurance coverage for treatments will change as well as special education programs.

Some evidence based on brain lesion case studies also suggests that the anterior ventromedial prefrontal and cingulate cortices may be involved in abnormal hoarding behaviors, but sufferers of such injuries display less purposeful behavior than other individuals who hoard compulsively, thus making the involvement of these brain structures unclear. Other neuropsychological factors that have been found to be associated with individuals exhibiting hoarding behaviors include slower and more variable reaction times, increased impulsivity, and decreased spatial attention. A study comparing neural activity in hoarders, people with OCD, and a control group when deciding to throw possessions away found that when hoarders were trying to decide to throw away their own possessions, they had lower activity in the anterior cingulate cortex and insula regions of the brain. The study suggested this lower activity was related to "problems in identifying the emotional significance of a stimulus, generating appropriate emotional response, or regulating affective state during decision making." Hoarders had normal levels of activity in those regions when making decisions about possessions that did not belong to them.

Kleptomania or klopemania is the inability to refrain from the urge for stealing items and is usually done for reasons other than personal use or financial gain. First described in 1816, kleptomania is classified in psychiatry as an impulse control disorder. Some of the main characteristics of the disorder suggest that kleptomania could be an obsessive-compulsive spectrum disorder.

The disorder is frequently under-diagnosed and is regularly associated with other psychiatric disorders, particularly anxiety and eating disorders, and alcohol and substance abuse. Patients with kleptomania are typically treated with therapies in other areas due to the comorbid grievances rather than issues directly related to kleptomania.

Over the last 100 years, a shift from psychotherapeutic to psychopharmacological interventions for kleptomania has occurred. Pharmacological treatments using selective serotonin reuptake inhibitors (SSRIs), mood stabilizers and opioid receptor antagonists, and other antidepressants along with cognitive behavioral therapy, have yielded positive results.

Compulsive behavior is defined as performing an act persistently and repetitively without it necessarily leading to an actual reward or pleasure. Compulsive behaviors could be an attempt to make obsessions go away. The act is usually a small, restricted and repetitive behavior, yet not disturbing in a pathological way. Compulsive behaviors are a need to reduce apprehension caused by internal feelings a person wants to abstain from or control. A major cause of the compulsive behaviors is said to be obsessive–compulsive disorder (OCD). "The main idea of compulsive behavior is that the likely excessive activity is not connected to the purpose to which it appears directed." Furthermore, there are many different types of compulsive behaviors including, shopping, hoarding, eating, gambling, trichotillomania and picking skin, checking, counting, washing, sex, and more. Also, there are cultural examples of compulsive behavior.

A study done in 1995 of 811 university students in the United States found 5.2% of that population had results indicating they were talkaholics. A similar study from the same year with students from New Zealand found similar results, with 4.7% scoring above 40.

The cause of OCPD is unknown. However, it is believed to involve a combination of genetic and environmental factors. Under the genetic theory, people with a form of the DRD3 gene will probably develop OCPD and depression, particularly if they are male. But genetic concomitants may lie dormant until triggered by events in the lives of those who are predisposed to OCPD. These events could include trauma faced during childhood, such as physical, emotional, or sexual abuse, or other psychological trauma. Under the environmental theory, OCPD is a learned behavior.

The psychological and mental effects can prove intense and plague an individual for years. These include hopelessness, powerlessness, isolation, shame, depression, self-loathing, guilt, suicidal thoughts, suicide attempts, and/or self-injurious behaviors.

An addictive behavior is a behavior, or a stimulus related to a behavior (e.g., sex or food), that is both rewarding and reinforcing, and is associated with the development of an addiction. Addictions involving addictive behaviors are normally referred to as behavioral addictions.