The ICD, DSM and CCMD list promiscuity as a prevalent and problematic symptom for [[Borderline personality disorder|Borderline Personality Disorder]]. Individuals with this diagnosis sometimes engage in sexual behaviors which can appear out of control causing distress to the individual or attracting negative reception from others. There is therefore a risk that a person presenting with sex addiction, may in fact be suffering from Borderline Personality Disorder. This may lead to inappropriate or incomplete treatment

Sexual addiction, also known as sex addiction, is a state characterized by [[compulsive]] participation or engagement in [[Human sexual activity|sexual activity]], particularly [[sexual intercourse]], despite negative consequences. Proponents of a [[diagnostic model]] for sexual addiction, as defined here, consider it to be one of several sex-related disorders within an umbrella concept known as [[hypersexual disorder]]. The term "sexual dependence" is also used to refer to people who report being unable to control their [[sexual urges]], behaviors, or thoughts. Related models of pathological sexual behavior include [[hypersexuality]] (nymphomania and satyriasis), [[erotomania]], [[Don Juanism]] (or Don Juanitaism), and [[paraphilia]]-related disorders.

The concept of sexual addiction is contentious. There is considerable debate amongst [[psychiatrists]], psychologists, [[sexologist]]s, and other specialists whether compulsive sexual behavior constitutes an addiction, and therefore its classification and possible diagnosis. , sexual addiction is not a clinical diagnosis in either the [[Diagnostic and Statistical Manual of Mental Disorders|DSM]] or [[International Statistical Classification of Diseases and Related Health Problems|ICD]] medical classifications of diseases and medical disorders. Some argue that applying such concepts to normal behaviors such as sex, can be problematic, and suggest that applying medical models such as addiction to human sexuality can serve to [[Slut-shaming|pathologise normal behavior]] and cause harm

Neuroscientists, pharmacologists, molecular biologists, and other researchers in related fields have identified the [[transcription factor|transcriptional]] and [[epigenetic]] mechanisms of addiction [[pathophysiology]]. Diagnostic models, which use the pharmacological model of addiction (this model associates addiction with drug-related concepts, particularly [[physical dependence]], [[drug withdrawal]], and [[drug tolerance]]), do not currently include diagnostic criteria to identify sexual addictions in a clinical setting. In the brain disease model of addiction, which uses neuropsychological concepts to characterize addictions, sexual addictions are identifiable and well-characterized. In this model, [[addictive drugs]] are characterized as those which are both [[reinforcing]] and [[reward system|rewarding]]. Addictive behaviors (those which can induce a compulsive state) are similarly identified and characterized by their rewarding and reinforcing properties.

In "Sexual Addiction and Compulsivity", authors Taylor and Francis argue that: "Obsessive sexual behavior illness is defined by a continual pattern of failure to control intense, repetitive sexual impulses or urges."

Internet sex addiction, also known as cybersex addiction, has been proposed as a sexual addiction characterized by virtual Internet sexual activity that causes serious negative consequences to one's physical, mental, social, and/or financial well-being. It may also be considered a subset of the theorized Internet addiction disorder. Internet sex addiction manifests various behaviours: reading erotic stories; viewing, downloading or trading online pornography; online activity in adult fantasy chat rooms; cybersex relationships; masturbation while engaged in online activity that contributes to one's sexual arousal; the search for offline sexual partners and information about sexual activity.

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

There is an ongoing debate in the medical community concerning the insufficient studies, and of those, their quality, or lack thereof, and the resulting analysis and conclusions drawn from them, such as they are. So far, without repeatable, meaningful, measurable, and quantifiable analysis, no medical community wide acceptably reasonable standards, a definition, have been drawn yet.

Hence, internet sex addiction, just like it's umbrella sexual addiction, is still not listed in the DSM-5, which is commonly used by psychiatrists in the United States for diagnosing patients problems in a standard uniform way.

Addiction is defined by Webster Dictionary as a "compulsive need for and use of a habit-forming substance characterized by tolerance and by well-defined physiological symptoms upon withdrawal; broadly: persistent compulsive use of a substance known by the user to be harmful".

Problematic Internet use is also called compulsive Internet use (CIU), Internet overuse, problematic computer use, or pathological computer use (PCU), problematic Internet use (PIU), or Internet addiction disorder (IAD)). Another commonly associated pathology is video game addiction, or Internet gaming disorder (IGD).

Research by governments in Australia led to a universal definition for that country which appears to be the only research-based definition not to use diagnostic criteria: "Problem gambling is characterized by many difficulties in limiting money and/or time spent on gambling which leads to adverse consequences for the gambler, others, or for the community." The University of Maryland Medical Center defines pathological gambling as "being unable to resist impulses to gamble, which can lead to severe personal or social consequences".

Most other definitions of problem gambling can usually be simplified to any gambling that causes harm to the gambler or someone else in any way; however, these definitions are usually coupled with descriptions of the type of harm or the use of diagnostic criteria. The "DSM-V" has since reclassified pathological gambling as "gambling disorder" and has listed the disorder under substance-related and addictive disorders rather than impulse-control disorders. This is due to the symptomatology of the disorder resembling an addiction not dissimilar to that of substance-abuse. There are both environmental and genetic factors that can influence on gambler and cause some type of addiction. In order to be diagnosed, an individual must have at least four of the following symptoms in a 12-month period:

- Needs to gamble with increasing amounts of money in order to achieve the desired excitement

- Is restless or irritable when attempting to cut down or stop gambling

- Has made repeated unsuccessful efforts to control, cut back, or stop gambling

- Is often preoccupied with gambling (e.g., having persistent thoughts of reliving past gambling experiences, handicapping or planning the next venture, thinking of ways to get money with which to gamble)

- Often gambles when feeling distressed (e.g., helpless, guilty, anxious, depressed)

- After losing money gambling, often returns another day to get even ("chasing" one's losses)

- Lies to conceal the extent of involvement with gambling

- Has jeopardized or lost a significant relationship, job, education or career opportunity because of gambling

- Relies on others to provide money to relieve desperate financial situations caused by gambling

Psychological dependence is a form of dependence that involves emotional–motivational withdrawal symptoms (e.g., a state of unease or dissatisfaction, a reduced capacity to experience pleasure, or anxiety) upon cessation of drug use or engagement in certain behaviors. Physical and psychological dependence are sometimes classified as a facet or component of addiction, such as in the DSM-IV-TR; however, some drugs which produce dependence syndromes do not produce addiction, and vice versa, in humans. Addiction and psychological dependence are both mediated through reinforcement, a form of operant conditioning, but are associated with different forms of reinforcement. Addiction is a compulsion for rewarding stimuli that is mediated through positive reinforcement. Psychological dependence, which is mediated through negative reinforcement, involves a desire to use a drug or perform a behavior to avoid the unpleasant withdrawal syndrome that results from cessation of exposure to it.

Psychological dependence develops through consistent and frequent exposure to a stimulus. Behaviors which can produce observable psychological withdrawal symptoms (i.e., cause psychological dependence) include physical exercise, shopping, sex and self-stimulation using pornography, and eating food with high sugar or fat content, among others. Behavioral therapy is typically employed to help individuals overcome psychological dependence upon drugs or maladaptive behaviors that produce psychological dependence.

Compulsions and addictions are intertwined and reward is one major distinction between an addiction and a compulsion (as it is experienced in obsessive-compulsive disorder). An addiction is, by definition, a form of compulsion, and both addictions and compulsions involve operant reinforcement; however, in addiction, the desire and motivation to use a substance or engage in a behavior arises because it is rewarding (i.e., the compulsions that occur in addiction develop through positive reinforcement). In contrast, someone who experiences a compulsion as part of obsessive-compulsive disorder may not perceive anything rewarding from acting on the compulsion. Often, it is a way of dealing with the obsessive part of the disorder, resulting in a feeling of relief (i.e., compulsions may also arise through negative reinforcement).

Deep brain stimulation to the nucleus accumbens, a region in the brain involved heavily in addiction and reinforcement learning, has proven to be an effective treatment of obsessive compulsive disorder.

Experts describe the spectrum of behaviors designated as addictive in terms of five interrelated concepts: patterns, habits, compulsions, impulse control disorders, and physical addiction.

The DSM definition of addiction can be boiled down to compulsive use of a substance (or engagement in an activity) despite ongoing negative consequences. The medical community makes a distinction between physical dependence (characterized by symptoms of physical withdrawal symptoms, like tremors and sweating) and psychological dependence (emotional-motivational withdrawal symptoms). Physical dependence is simply needing a substance to function. Humans are all physically dependent upon oxygen, food and water. A drug can cause physical dependence and not psychological dependence (for example, some blood pressure medications, which can produce fatal withdrawal symptoms if not tapered) and some can cause psychological dependence without physical dependence (the withdrawal symptoms associated with cocaine are all psychological, there is no associated vomiting or diarrhea as there is with opiate withdrawal).

There are several different screening tools that have been validated for use with adolescents such as the CRAFFT and adults such as the CAGE.

Physical dependence on a substance is defined by the appearance of characteristic physical withdrawal symptoms when the substance is suddenly discontinued. Opiates, benzodiazepines, barbiturates, alcohol and nicotine induce physical dependence. On the other hand, some categories of substances share this property and are still not considered addictive: cortisone, beta blockers and most antidepressants are examples.

Some substances induce physical dependence or physiological tolerance - but not addiction — for example many laxatives, which are not psychoactive; nasal decongestants, which can cause rebound congestion if used for more than a few days in a row; and some antidepressants, most notably venlafaxine, paroxetine and sertraline, as they have quite short half-lives, so stopping them abruptly causes a more rapid change in the neurotransmitter balance in the brain than many other antidepressants. Many non-addictive prescription drugs should not be suddenly stopped, so a doctor should be consulted before abruptly discontinuing them.

The speed with which a given individual becomes addicted to various substances varies with the substance, the frequency of use, the means of ingestion, the intensity of pleasure or euphoria, and the individual's genetic and psychological susceptibility. Some people may exhibit alcoholic tendencies from the moment of first intoxication, while most people can drink socially without ever becoming addicted. Opioid dependent individuals have different responses to even low doses of opioids than the majority of people, although this may be due to a variety of other factors, as opioid use heavily stimulates pleasure-inducing neurotransmitters in the brain. Nonetheless, because of these variations, in addition to the adoption and twin studies that have been well replicated, much of the medical community is satisfied that addiction is in part genetically moderated. That is, one's genetic makeup may regulate how susceptible one is to a substance and how easily one may become attached to a pleasurable routine.

Eating disorders are complicated pathological mental illnesses and thus are not the same as addictions described in this article. Eating disorders, which some argue are not addictions at all, are driven by a multitude of factors, most of which are highly different from the factors behind addictions described in this article. It has been reported, however, that patients with eating disorders can successfully be treated with the same non-pharmacological protocols used in patients with chemical addiction disorders.

Gambling is another potentially addictive behavior with some biological overlap. Conversely gambling urges have emerged with the administration of Mirapex (pramipexole), a dopamine agonist.

The obsolete term physical addiction is deprecated, because of its connotations. In modern pain management with opioids physical dependence is nearly universal. High-quality, long-term studies are needed to better delineate the risks and benefits of chronic opiate use.

CBD is frequently comorbid with mood, anxiety, substance abuse and eating disorders. People who score highly on compulsive buying scales tend to understand their feelings poorly and have low tolerance for unpleasant psychological states such as bad moods. Onset of CBD occurs in the late teens and early twenties and is generally chronic. CBD is similar to, but distinguished from, OCD hoarding and mania. Compulsive buying is not limited to people who spend beyond their means; it also includes people who spend an inordinate amount of time shopping or who chronically think about buying things but never purchase them. Promising treatments for CBD include medication such as selective serotonin reuptake inhibitors (SSRIs), and support groups such as Debtors Anonymous.

Problem gambling (or ludomania, but usually referred to as "gambling addiction" or "compulsive gambling") is an urge to gamble continuously despite harmful negative consequences or a desire to stop. Problem gambling is often defined by whether harm is experienced by the gambler or others, rather than by the gambler's behaviour. Severe problem gambling may be diagnosed as clinical pathological gambling if the gambler meets certain criteria. Pathological gambling is a common disorder that is associated with both social and family costs.

The "DSM-5" has re-classified the condition as an addictive disorder, with sufferers exhibiting many similarities to those who have substance addictions.

The term "gambling addiction" has long been used in the recovery movement. Pathological gambling was long considered by the American Psychiatric Association to be an impulse control disorder rather than an addiction. However, data suggest a closer relationship between pathological gambling and substance use disorders than exists between PG and obsessive-compulsive disorder, largely because the behaviors in problem gambling and most primary substance use disorders ("i.e.", those not resulting from a desire to "self-medicate" for another condition such as depression) seek to activate the brain's reward mechanisms while the behaviors characterizing obsessive-compulsive disorder are prompted by overactive and misplaced signals from the brain's fear mechanisms.

Problem gambling is an addictive behavior with a high comorbidity with alcohol problems. Comorbidity is the presence of one or more diseases or disorders co-occurring with each other. A common feature shared by people who suffer from gambling addiction is impulsivity.

An addictive personality refers to a particular set of personality traits that make an individual predisposed to developing addictions. This hypothesis states that there may be common personality traits observable in people suffering from addiction. Alan R. Lang of Florida State University, author of an addiction study prepared for the United States National Academy of Sciences, said, "If we can better identify the personality factors, they can help us devise better treatment and can open up new strategies to intervene and break the patterns of addiction."

Excessive computer use may result in, or occur with:

- Lack of face to face social interaction

- Computer vision syndrome

The terms compulsive shopping, compulsive buying, and compulsive spending are often used interchangeably, but the behaviors they represent are in fact distinct. (Nataraajan and Goff 1992) One may buy without shopping, and certainly shop without buying: of compulsive shoppers, some 30% described the act of buying itself as providing a buzz, irrespective of the goods purchased.

Codependency is a type of dysfunctional helping relationship where one person supports or enables another person's drug addiction, alcoholism, gambling addiction, poor mental health, immaturity, irresponsibility, or under-achievement. Among the core characteristics of codependency, the most common theme is an excessive reliance on other people for approval and a sense of identity.

Given its grassroots origin, the precise definition of codependency varies based on the source but can be generally characterized as a subclinical and situational or episodic behavior similar to that of dependent personality disorder. In its broadest definition, a codependent is someone who cannot function from their innate self and whose thinking and behavior is instead organized around another person, or even a process, or substance. In this context, people who are addicted to a substance, like drugs, or a process, like gambling or sex, can also be considered codependent. In its most narrow definition, it requires one person to be physically or psychologically addicted, such as to heroin, and the second person to be psychologically dependent on that behavior. Some users of the codependency concept use the word as an alternative to using the concept of dysfunctional families, without statements that classify it as a disease.

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.

Television addiction is a proposed addiction model associated with maladaptive or compulsive behavior associated with watching television programming. The most recent medical review on this model concluded that pathological television watching behavior may constitute a true behavioral addiction, but indicated that much more research on this topic is needed to demonstrate this. The compulsion can be extremely difficult to control in many cases. The television addiction model has parallels to other forms of behavioral addiction, such as addiction to drugs or gambling, which are also forms of compulsive behavior.

Television addiction is not a diagnosable condition of DSM-IV.

Behavioral addiction is a form of addiction that involves a compulsion to engage in a rewarding non-drug-related behavior – sometimes called a natural reward – despite any negative consequences to the person's physical, mental, social or financial well-being. A gene transcription factor known as ΔFosB has been identified as a necessary common factor involved in both behavioral and drug addictions, which are associated with the same set of neural adaptations in the reward system.

People with hypersexual disorder experience multiple, unsuccessful attempts to control or diminish the amount of time spent engaging in sexual fantasies, urges, and behaviors in response to dysphoric mood states or stressful life events.

For a valid diagnosis of hypersexual disorder to be established, symptoms must persist for a period of at least 6 months and occur independently of a use mania or a medical condition.

Cannabis use is associated with comorbid mental health problems, such as mood and anxiety disorders, and discontinuing cannabis use is difficult for some users. Psychiatric comorbidities are often present in dependent cannabis users including a range of personality disorders.

Computers nowadays rely almost entirely on the internet and thus relevant research articles relating to internet addiction may also be relevant to computer addiction.

- Gaming addiction: a hypothetical behavioral addiction characterized by excessive or compulsive use of computer games or video games, which interferes with a person's everyday life. Video game addiction may present itself as compulsive gaming, social isolation, mood swings, diminished imagination, and hyper-focus on in-game achievements, to the exclusion of other events in life.

- Social media addiction: Data suggest that participants use social media to fulfill their social needs, but are typically dissatisfied. Lonely individuals are drawn to the Internet for emotional support. This could interfere with "real life socializing" by reducing face-to-face relationships. Some of these views are summed up in an Atlantic article by Stephen Marche entitled "Is Facebook Making Us Lonely?", in which the author argues that social media provides more breadth, but not the depth of relationships that humans require and that users begin to find it difficult to distinguish between the meaningful relationships which we foster in the real world, and the numerous casual relationships that are formed through social media.

Cannabis withdrawal symptoms can occur in one half of patients in treatment for cannabis use disorders. These symptoms include dysphoria (anxiety, irritability, depression, restlessness), disturbed sleep, gastrointestinal symptoms, and decreased appetite. Most symptoms begin during the first week of abstinence and resolve after a few weeks.

According to the National Cannabis Prevention and Information Centre in Australia, a sign of cannabis dependence is that an individual spends noticeably more time than the average recreational user recovering from the use of or obtaining cannabis. For some, using cannabis becomes a substantial and disruptive part of an individual's life and he or she may exhibit difficulties in meeting personal obligations or participating in important life activities, preferring to use cannabis instead. People who are cannabis dependent have the inability to stop or decrease using cannabis on their own.