The Alcohol Use Disorders Identification Test (AUDIT) is considered the most accurate alcohol screening tool for identifying potential alcohol misuse, including dependence. It was developed by the World Health Organisation, designed initially for use in primary healthcare settings with supporting guidance.

The Severity of Alcohol Dependence Questionnaire (SADQ or SAD-Q) is a 20 item clinical screening tool designed to measure the presence and level of alcohol dependence.

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

Some recommendations for screening tools for substance misuse in pregnancy include that they take less than 10 minutes, should be used routinely, include an educational component. Tools suitable for pregnant women include i.a. 4Ps, T-ACE, TWEAK, TQDH (Ten-Question Drinking History), and AUDIT.

Cannabis use disorder is recognized in the fifth version of the "Diagnostic and Statistical Manual of Mental Disorders" (DSM-5), which added cannabis withdrawal as a new condition. In the United States, the average adult who seeks treatment has consumed cannabis for over 10 years almost daily and has actively attempted to quit six or more times.

No medications have been found effective for cannabis dependence as of 2014, but psychotherapeutic models hold promise.

The most commonly accessed forms of treatment in Australia are 12-step programmes, physicians, rehabilitation programmes, and detox services, with inpatient and outpatient services equally accessed. In the EU approximately 20% of all primary admissions and 29% of all new drug clients in 2005, had primary cannabis problems. And in all countries that reported data between 1999–2005 the number of people seeking treatment for cannabis use increased.

Treatment options for cannabis dependence are far fewer than for opiate or alcohol dependence. Most treatment falls into the categories of psychological or psychotherapeutic, intervention, pharmacological intervention or treatment through peer support and environmental approaches. Screening and brief intervention sessions can be given in a variety of settings, particularly at doctor's surgeries, which is of importance as most cannabis users seeking help will do so from their general practitioner rather than a drug treatment service agency.

Clinicians differentiate between casual users who have difficulty with drug screens, and daily heavy users, to a chronic user who uses multiple times a day. The sedating and anxiolytic properties of THC in some users might make the use of cannabis an attempt to self-medicate personality or psychiatric disorders.

The Alcohol Use Disorders Identification Test (AUDIT) is considered the most accurate alcohol screening tool for identifying potential alcohol misuse, including dependence. It was developed by the World Health Organisation, designed initially for use in primary healthcare settings with supporting guidance.

The DSM-5 guidelines for diagnosis of opioid use disorder require that the individual has significant impairment or distress related to opioid uses. In order to make the diagnosed two or more of eleven criteria must be present in a given year:

1. More opioids are taken than intended

2. The individual is unable to decrease the amount of opioids used

3. Large amounts of time are spent trying to obtain opioids, use opioids, or recover from taking them

4. The individual has cravings for opioids

5. Difficulty fulfilling professional duties at work or school

6. Continued use of opioids leading to social and interpersonal consequences

7. Decreased social or recreational activities

8. Using opioids despite it being physically dangerous settings

9. Continued use despite opioids worsening physical or psychological health (i.e. depression, constipation)

10. Tolerance

11. Withdrawal

Preventing or reducing the harm has been called for via increased taxation of alcohol, stricter regulation of alcohol advertising and the provision of brief Interventions. Brief Interventions for alcohol abuse reduce the incidence of unsafe sex, sexual violence, unplanned pregnancy and, likely, STD transmission. Information and education on social norms and the harms associated with alcohol abuse delivered via the internet or face-to-face has not been found to result in any meaningful benefit in changing harmful drinking behaviours in young people.

According to European law, individuals who are suffering from alcohol abuse or other related problems cannot be given a license, or if in possession of a license cannot get it renewed. This is a way to prevent individuals driving under the influence of alcohol, but does not prevent alcohol abuse per se.

An individual's need for alcohol can depend on their family's alcohol use history. For instance, if it is discovered that their family history with alcohol has a strong pattern, there might be a need for education to be set in place to reduce the likelihood of reoccurrence (Powers, 2007). However, studies have established that those with alcohol abuse tend to have family members who try to provide help. In many of these occasions the family members would try to help the individual to change or to help improve the individual's lifestyle.

For a diagnosis of benzodiazepine dependence to be made, the ICD-10 requires that at least 3 of the below criteria are met and that they have been present for at least a month, or, if less than a month, that they appeared repeatedly during a 12-month period.

- Behavioral, cognitive, and physiological phenomena that are associated with the repeated use and that typically include a strong desire to take the drug.

- Difficulty controlling use

- Continued use despite harmful consequences

- Preference given to drug use rather than to other activities and obligations

- Increased tolerance to effects of the drug and sometimes a physical withdrawal state.

These diagnostic criteria are good for research purposes, but, in everyday clinical practice, they should be interpreted according to clinical judgement. In clinical practice, benzodiazepine dependence should be suspected in those having used benzodiazepines for longer than a month, in particular, if they are from a high-risk group. The main factors associated with an increased incidence of benzodiazepine dependence include:

- Dose

- Duration

- Concomitant use of antidepressants

Benzodiazepine dependence should be suspected also in individuals having substance use disorders including alcohol, and should be suspected in individuals obtaining their own supplies of benzodiazepines. Benzodiazepine dependence is almost certain in individuals who are members of a tranquilizer self-help group.

Research has found that about 40 percent of people with a diagnosis of benzodiazepine dependence are not aware that they are dependent on benzodiazepines, whereas about 11 percent of people judged not to be dependent believe that they are.

When assessing a person for benzodiazepine dependence, asking specific questions rather than questions based on concepts is recommended by experts as the best approach of getting a more accurate diagnosis. For example, asking persons if they "think about the medication at times of the day other than when they take the drug" would provide a more meaningful answer than asking "do you think you are psychologically dependent?". The Benzodiazepine Dependence Self Report Questionnaire is one questionnaire used to assess and diagnose benzodiazepine dependence.

There are efforts to decrease the number of opioids prescribed in an effort to decrease opioid use disorder and deaths related to opioid use.

It is common for individuals with drugs use disorder to have other psychological problems. The terms “dual diagnosis” or “co-occurring disorders,” refer to having a mental health and substance use disorder at the same time. According to the British Association for Psychopharmacology (BAP), “symptoms of psychiatric disorders such as depression, anxiety and psychosis are the rule rather than the exception in patients misusing drugs and/or alcohol.”

Individuals who have a comorbid psychological disorder often have a poor prognosis if either disorder is untreated. Historically most individuals with dual diagnosis either received treatment only for one of their disorders or they didn’t receive any treatment all. However, since the 1980s, there has been a push towards integrating mental health and addiction treatment. In this method, neither condition is considered primary and both are treated simultaneously by the same provider.

Some medical systems, including those of at least 15 states of the United States, refer to an Addiction Severity Index to assess the severity of problems related to substance use. According to DARA Thailand, the index assesses potential problems in seven categories: medical, employment/support, alcohol, other drug use, legal, family/social, and psychiatric.

Many hospitals use the Clinical Institute Withdrawal Assessment for Alcohol (CIWA) protocol in order to assess the level of withdrawal present and therefore the amount of medication needed. When overuse of alcohol is suspected but drinking history is unclear, testing for elevated values of carbohydrate-deficient transferrin or gammaglutamyl transferase can help make the diagnosis of alcohol overuse and dependence more clear. The CIWA has also been shortened (now called the CIWA-Ar), while retaining its validity and reliability, to help assess patients more efficiently due to the life-threatening nature of alcohol withdrawal.

Other conditions that may present similarly include benzodiazepine withdrawal syndrome (a condition also mainly caused by GABA receptor adaptation).

Benzodiazepines are regarded as a highly addictive drug class. A psychological and physical dependence can develop in as short as a few weeks but may take years to develop in other individuals. Patients wanting to withdraw from benzodiazepines typically receive little advice or support, and such withdrawal should be by small increments over a period of months.

Benzodiazepines are usually prescribed only short-term, as there is little justification for their prescribing long-term. Some doctors however, disagree and believe long-term use beyond 4 weeks is sometimes justified, although there is little data to support this viewpoint. Such viewpoints are a minority in the medical literature.

There is no evidence that "drug holidays" or periods of abstinence reduced the risk of dependence; there is evidence from animal studies that such an approach does not prevent dependence from happening. Use of short-acting benzodiazepines is associated with interdose withdrawal symptoms. Kindling has clinical relevance with regard to benzodiazepines; for example, there is an increasing shift to use of benzodiazepines with a shorter half-life and intermittent use, which can result in interdose withdrawal and rebound effects.

The World Health Organization, the European Union and other regional bodies, national governments and parliaments have formed alcohol policies in order to reduce the harm of alcoholism. Targeting adolescents and young adults is regarded as an important step to reduce the harm of alcohol abuse. Increasing the age at which licit drugs of abuse such as alcohol can be purchased, the banning or restricting advertising of alcohol has been recommended as additional ways of reducing the harm of alcohol dependence and abuse. Credible, evidence based educational campaigns in the mass media about the consequences of alcohol abuse have been recommended. Guidelines for parents to prevent alcohol abuse amongst adolescents, and for helping young people with mental health problems have also been suggested.

Addiction is a complex but treatable condition. It is characterized by compulsive drug craving, seeking, and use that persists even if the user is aware of severe adverse consequences. For some people, addiction becomes chronic, with periodic relapses even after long periods of abstinence. As a chronic, relapsing disease, addiction may require continued treatments to increase the intervals between relapses and diminish their intensity. While some with substance issues recover and lead fulfilling lives, others require ongoing additional support. The ultimate goal of addiction treatment is to enable an individual to manage their substance misuse; for some this may mean abstinence. Immediate goals are often to reduce substance abuse, improve the patient's ability to function, and minimize the medical and social complications of substance abuse and their addiction; this is called "harm reduction".

Treatments for addiction vary widely according to the types of drugs involved, amount of drugs used, duration of the drug addiction, medical complications and the social needs of the individual. Determining the best type of recovery program for an addicted person depends on a number of factors, including: personality, drugs of choice, concept of spirituality or religion, mental or physical illness, and local availability and affordability of programs.

Many different ideas circulate regarding what is considered a successful outcome in the recovery from addiction. Programs that emphasize controlled drinking exist for alcohol addiction. Opiate replacement therapy has been a medical standard of treatment for opioid addiction for many years.

Treatments and attitudes toward addiction vary widely among different countries. In the US and developing countries, the goal of commissioners of treatment for drug dependence is generally total abstinence from all drugs. Other countries, particularly in Europe, argue the aims of treatment for drug dependence are more complex, with treatment aims including reduction in use to the point that drug use no longer interferes with normal activities such as work and family commitments; shifting the addict away from more dangerous routes of drug administration such as injecting to safer routes such as oral administration; reduction in crime committed by drug addicts; and treatment of other comorbid conditions such as AIDS, hepatitis and mental health disorders. These kinds of outcomes can be achieved without eliminating drug use completely. Drug treatment programs in Europe often report more favorable outcomes than those in the US because the criteria for measuring success are functional rather than abstinence-based. The supporters of programs with total abstinence from drugs as a goal believe that enabling further drug use means prolonged drug use and risks an increase in addiction and complications from addiction.

Little attention has focused on the degree that benzodiazepines are abused as a primary drug of choice, but they are frequently abused alongside other drugs of abuse, especially alcohol, stimulants and opiates. The benzodiazepine most commonly abused can vary from country to country and depends on factors including local popularity as well as which benzodiazepines are available. Nitrazepam for example is commonly abused in Nepal and the United Kingdom, whereas in the United States of America where nitrazepam is not available on prescription other benzodiazepines are more commonly abused. In the United Kingdom and Australia there have been epidemics of temazepam abuse. Particular problems with abuse of temazepam are often related to gel capsules being melted and injected and drug-related deaths. Injecting most benzodiazepines is dangerous because of their relative insolubility in water (with the exception of midazolam), leading to potentially serious adverse health consequences for users.

Benzodiazepines are a commonly misused class of drug. A study in Sweden found that benzodiazepines are the most common drug class of forged prescriptions in Sweden. Concentrations of benzodiazepines detected in impaired motor vehicle drivers often exceeding therapeutic doses have been reported in Sweden and in Northern Ireland. One of the hallmarks of problematic benzodiazepine drug misuse is escalation of dose. Most licit prescribed users of benzodiazepines do not escalate their dose of benzodiazepines.

Problem benzodiazepine use can be associated with various deviant behaviors, including drug-related crime. In a survey of police detainees carried out by the Australian Government, both legal and illegal users of benzodiazepines were found to be more likely to have lived on the streets, less likely to have been in full-time work and more likely to have used heroin or methamphetamines in the past 30 days from the date of taking part in the survey. Benzodiazepine users were also more likely to be receiving illegal incomes and more likely to have been arrested or imprisoned in the previous year. Benzodiazepines were sometimes reported to be used alone, but most often formed part of a poly drug-using problem. Female users were more likely than men to be using heroin, whereas male users were more likely to report amphetamine use. Benzodiazepine users were more likely than non-users to claim government financial benefits and benzodiazepine users who were also poly-drug users were the most likely to be claiming government financial benefits. Those who reported using benzodiazepines alone were found to be in the mid-range when compared to other drug using patterns in terms of property crimes and criminal breaches. Of the detainees reporting benzodiazepine use, one in five reported injection use, mostly of illicit temazepam, with some who reported injecting prescribed benzodiazepines. The injection was a concern in this survey due to increased health risks. The main problems highlighted in this survey were concerns of dependence, the potential for overdose of benzodiazepines in combination with opiates and the health problems associated with injection of benzodiazepines.

Benzodiazepines are also sometimes used for drug facilitated sexual assaults and robbery, however, alcohol remains the most common drug involved in drug facilitated assaults. The muscle relaxant, disinhibiting and amnesia producing effects of benzodiazepines are the pharmacological properties which make these drugs effective in drug-facilitated crimes. Serial killer Jeffrey Dahmer admitted to using triazolam (Halcion), and occasionally temazepam (Restoril), in order to sedate his victims prior to murdering them.

In a 2017 publication, an analysis of the blood samples of 22 victims of drug-facilitated robberies in Bangladesh revealed that criminals use different mixtures of Benzodiazepines including Lorazepam, Midazolam, Diazepam and Nordiazepam to immobilize and then rob their victims.

In the United States, cocaine use results in about 5,000–6,000 deaths annually.

"Substance dependence", as defined in the DSM, can be diagnosed with physiological dependence, evidence of tolerance or withdrawal, or without physiological dependence.

DSM-5 substance dependencies include:

- 303.90 Alcohol dependence

- 304.00 Opioid dependence

- 304.10 Sedative, hypnotic, or anxiolytic dependence (including benzodiazepine dependence and barbiturate dependence)

- 304.20 Cocaine dependence

- 304.30 Cannabis dependence

- 304.40 Amphetamine dependence (or amphetamine-like)

- 304.50 Hallucinogen dependence

- 304.60 Inhalant dependence

- 304.80 Polysubstance dependence

- 304.90 Phencyclidine (or phencyclidine-like) dependence

- 304.90 Other (or unknown) substance dependence

- 305.10 Nicotine dependence

There are effective treatments for nicotine dependence, although the majority of the evidence focuses on treatments for cigarette smokers rather than people who use other forms of tobacco (e.g., chew, snus, pipes, hookah, electronic cigarettes). These treatments have been shown to double or even triple a smoker’s chances of quitting successfully.

There are approximately 976 million smokers in the world. Estimates are that half of smokers (and one-third of former smokers) are dependent based on DSM criteria, regardless of age, gender or country of origin, but this could be higher if different definitions of dependence were used. Recent data suggest that, in the United States, the rates of daily smoking and the number of cigarettes smoked per day are declining, suggesting a reduction in population-wide dependence among current smokers. However, there are different groups of people who are more likely to smoke than the average population, such as those with low education or low socio-economic status and those with mental illness. There is also evidence that among smokers, some subgroups may be more dependent than other groups. Men smoke at higher rates than do women and score higher on dependence indices; however, women may be less likely to be successful in quitting, suggesting that women may be more dependent by that criterion. Higher nicotine dependence has also been linked with mental illness, including anxiety and depression.

There are reliable tests for the actual use of alcohol, one common test being that of blood alcohol content (BAC). These tests do not differentiate alcoholics from non-alcoholics; however, long-term heavy drinking does have a few recognizable effects on the body, including:

- Macrocytosis (enlarged MCV)

- Elevated GGT

- Moderate elevation of AST and ALT and an AST: ALT ratio of 2:1

- High carbohydrate deficient transferrin (CDT)

With regard to alcoholism, BAC is useful to judge alcohol tolerance, which in turn is a sign of alcoholism.

However, none of these blood tests for biological markers is as sensitive as screening questionnaires.

Medical organizations strongly discourage drinking alcohol during pregnancy. Alcohol passes easily from the mother's bloodstream through the placenta and into the bloodstream of the fetus, which interferes with brain and organ development. Alcohol can affect the fetus at any stage during pregnancy, but the level of risk depends on the amount and frequency of alcohol consumed. Regular heavy drinking and binge drinking (four or more drinks on any one occasion) pose the greatest risk for harm, but lesser amounts can cause problems as well. There is no known safe amount or safe time to drink during pregnancy.

Prenatal alcohol exposure can lead to fetal alcohol spectrum disorders (FASDs). The most severe form of FASD is fetal alcohol syndrome (FAS). Problems associated with FASD include facial anomalies, low birth weight, stunted growth, small head size, delayed or uncoordinated motor skills, hearing or vision problems, learning disabilities, behavior problems, and inappropriate social skills compared to same-age peers. Those affected are more likely to have trouble in school, legal problems, participate in high-risk behaviors, and develop substance use disorders themselves.

Kim Janda has been working for years on a vaccination that would treat cocaine use disorders by limiting its rewarding effects.

Transcranial magnetic stimulation (TMS) is being studied as a treatment for cocaine addiction. So far studies have been undertaken by Medical University of South Carolina (MUSC), National Institute on Drug Abuse (NIDA), and Mexican National Institute of Psychiatry.