problematic internet use despite negative consequences to one's work, social, academic, or personal life. studies conducted in india, united states, asia, and europe have identified internet addiction prevalence rates ranging in value from 1% to 19%, with the adolescent population having high rates compared to other age groups. prevalence rates have been difficult to establish due to a lack of universally accepted diagnostic criteria, a lack of diagnostic instruments demonstrating cross-cultural validity and reliability, and existing controversy surrounding the validity of labeling problematic internet use as an addictive disorder. the most common scale used to measure addiction is the internet addiction test developed by kimberly young. people with internet addiction are likely to have a comorbid psychiatric disorder. comorbid diagnoses identified alongside internet addiction include affective mood disorders, anxiety disorders, substance use disorders, and attention deficit hyperactivity disorder. video games main article: video game addiction video game addiction is characterized by the world health organization (who) as excessive gaming behavior, potentially prioritized over other interests, despite the negative consequences that may arise, for a period of at least 12 months. in may 2019, the who introduced gaming disorder in the 11th edition of the international classification of diseases. video game addiction has been shown to be more prevalent in males than females, higher by 2.9 times. it has been suggested that people of younger ages are more prone to become addicted to video games. this may be due to video games being relatively new, hence the higher prevalence in younger groups. people with certain personalities may be more susceptible to gaming addictions. risk factors for video game addiction include: male, psychopathologies (e.g. adhd or mdd), and social anxiety. shopping main articles: shopping addiction and compulsive buying disorder shopping addiction, or compulsive buying disorder (cbd), is the excessive urge to shop or spend, potentially resulting in unwanted consequences. these consequences can have serious impacts, such as increased consumer debt, negatively affected relationships, increased risk of illegal behavior, and suicide attempts. shopping addiction occurs worldwide and has shown a 5.8% prevalence in the united states. similar to other behavioral addictions, cbd can be linked to mood disorders, substance use disorders, eating disorders, and other disorders involving a lack of control. signs and symptoms signs and symptoms of addiction can vary depending on the type of addiction. symptoms of drug addictions may include: continuation of drug use despite the knowledge of consequences disregarding financial status when it comes to drug purchases ensuring a stable supply of the drug experiencing withdrawal symptoms when stopping the drug needing more of the drug over time to achieve similar effects social and work life impacted due to drug use unsuccessful attempts to stop drug use urge to use drug regularly signs and symptoms of addiction may include: behavioral changes physical changes social changes angry and irritable changes to eating or sleeping habits changes to personality and attitude decreased attendance and performance in workplace or school setting fearful, paranoid and anxious without probable cause frequently engaging in conflicts (fights, illegal activity) frequent or sudden changes in mood and temperament hiding or in denial of certain behaviors lack of motivation periodic hyperactivity using substances in inappropriate settings abnormal pupil size bloodshot eyes body odor impaired motor coordination periodic tremors poor physical appearance slurred speech sudden changes in weight changes in hobbies changes to financial status (unexplained need for money) legal problems related to substance abuse sudden changes in friends and associates use of substance despite consequences to personal relationships screening and assessment addictions neuroclinical assessment the addictions neuroclinical assessment is used to diagnose addiction disorders. this tool measures three different domains: executive function, incentive salience, and negative emotionality. executive functioning consists of processes that would be disrupted in addiction. in the context of addiction, incentive salience determines how one perceives the addictive substance. increased negative emotional responses have been found with individuals with addictions. tobacco, alcohol, prescription medication, and other substance use (taps) this is a screening and assessment tool in one, assessing commonly used substances. this tool allows for a simple diagnosis, eliminating the need for several screening and assessment tools, as it includes both taps-1 and taps-2, screening and assessment tools respectively. the screening component asks about the frequency of use of the specific substance (tobacco, alcohol, prescription medication, and other). if an individual screens positive, the second component will begin. this dictates the risk level of the substance. crafft the crafft (car-relax-alone-forget-family and friends-trouble) is a screening tool that is used in medical centers. the crafft is in version 2.1 and has a version for nicotine and tobacco use called the crafft 2.1+n. this tool is used to identify substance use, substance related driving risk, and addictions among adolescents. this tool uses a set of questions for different scenarios. in the case of a specific combination of answers, different question sets can be used to yield a more accurate answer. after the questions, the dsm-5 criteria are used to identify the likelihood of the person having substance use disorder. after these tests are done, the clinician is to give the "5 rs" of brief counseling. the five rs of brief counseling includes: review screening results recommend to not use riding/driving risk counseling response: elicit self-motivational statements reinforce self-efficacy drug abuse screening test (dast-10) the drug abuse screening test (dast) is a self-reporting tool that measures problematic substance use. responses to this test are recorded as yes or no answers, and scored as a number between zero and 28. drug abuse or dependence, are indicated by a cut off score of 6. three versions of this screening tool are in use: dast-28, dast-20, and dast-10. each of these instruments are copyrighted by dr. harvey a. skinner. alcohol, smoking, and substance involvement test (assist) the alcohol, smoking, and substance involvement test (assist) is an interview-based questionnaire consisting of eight questions developed by the who. the questions ask about lifetime use; frequency of use; urge to use; frequency of health, financial, social, or legal problems related to use; failure to perform duties; if anyone has raised concerns over use; attempts to limit or moderate use; and use by injection. causes personality theories personality theories of addiction are psychological models that associate personality traits or modes of thinking (i.e., affective states) with an individual's proclivity for developing an addiction. data analysis demonstrates that psychological profiles of drug users and non-users have significant differences and the psychological predisposition to using different drugs may be different. models of addiction risk that have been proposed in psychology literature include: an affect dysregulation model of positive and negative psychological affects, the reinforcement sensitivity theory of impulsiveness and behavioral inhibition, and an impulsivity model of reward sensitization and impulsiveness. neuropsychology the transtheoretical model of change (ttm) can point to how someone may be conceptualizing their addiction and the thoughts around it, including not being aware of their addiction. cognitive control and stimulus control, which is associated with operant and classical conditioning, represent opposite processes (i.e., internal vs external or environmental, respectively) that compete over the control of an individual's elicited behaviors. cognitive control, and particularly inhibitory control over behavior, is impaired in both addiction and attention deficit hyperactivity disorder. stimulus-driven behavioral responses (i.e., stimulus control) that are associated with a particular rewarding stimulus tend to dominate one's behavior in an addiction. operant conditioningextinction reinforcementincrease behaviorpunishmentdecrease behavior positive reinforcementadd appetitive stimulusfollowing correct behaviornegative reinforcementpositive punishmentadd noxious stimulusfollowing behaviornegative punishmentremove appetitive stimulusfollowing behavior escaperemove noxious stimulusfollowing correct behavioractive avoidancebehavior avoids noxious stimulus stimulus control of behavior in operant conditioning, behavior is influenced by outside stimulus, such as a drug. the operant conditioning theory of learning is useful in understanding why the mood-altering or stimulating consequences of drug use can reinforce continued use (an example of positive reinforcement) and why the addicted person seeks to avoid withdrawal through continued use (an example of negative reinforcement). stimulus control is using the absence of the stimulus or presence of a reward to influence the resulting behavior. cognitive control of behavior