A substance that, when ingested, affects mental processes, e.g. cognition or affect. This term and its equivalent, psychotropic drug, are the most neutral and descriptive terms for the whole class of substances, licit and illicit, of interest to drug policy. "Psychoactive" does not necessarily imply dependence-producing, and in common parlance, the term is often left unstated, as in "drug use" or "substance abuse". (See also drug)

A cultural-political debate over whether general descriptive terms would give a favourable or unfavourable cast to the experience of mind-changing was conducted in many European and English-speaking countries in the 1960s and 1970s with regard to LSD and similar drugs. The terms ''psychotomimetic'' and ''hallucinogen'' (the latter became the accepted name for this class of drugs) conveyed an unfavourable connotation, while "psychedelic" and ''psycholytic'' gave a more favourable cast. ''psychedelic'', in particular, was also used with the same broad scope as "psychoactive" (The Journal of psychedelic drugs eventually changed to "psychoactive" in its title in 1981.) see also: psychotropic.

Impulse control disorder induced by multiple specified psychoactive substances is characterised by persistently repeated behaviours in which there is recurrent failure to resist an impulse, drive, or urge to perform an act that is rewarding to the person, at least in the short-term, despite longer-term harm either to the individual or to others (e.g., fire setting or stealing without apparent motive, repetitive sexual behaviour, aggressive outbursts) that develop during or soon after intoxication with or withdrawal from multiple specified psychoactive substances. The intensity or duration of the symptoms is substantially in excess of disturbances of impulse control that are characteristic of intoxication with or withdrawal from the multiple specified psychoactive substances. The amount and duration of the multiple specified psychoactive substances use must be capable of producing disturbances of impulse control. The symptoms are not better explained by a primary mental disorder (e.g., an Impulse control disorder, a Disorder due to addictive behaviours), as might be the case if the impulse control disturbances preceded the onset of the use of multiple specified psychoactive substances, if the symptoms persist for a substantial period of time after cessation of the multiple specified psychoactive substance use or withdrawal, or if there is other evidence of a pre-existing primary mental disorder with impulse control symptoms (e.g., a history of prior episodes not associated with multiple specified psychoactive substances use). (ICD-11 6C4F.73)

UNODC uses the term “new psychoactive substances (NPS)” which are defined as “substances of abuse, either in a pure form or a preparation, that are not controlled by the 1961 Single Convention on Narcotic Drugs or the 1971 Convention on Psychotropic Substances, but which may pose a public health threat”. The term “new” does not necessarily refer to new inventions — several NPS were first synthesized decades ago — but to substances that have recently become available on the market. NPS that have been placed under international control since 2014 continue to be included under the term NPS to enable times series analysis.

The main UNODC substance groups of NPS are aminoindanes (e.g. 5,6-methylenedioxy-2-aminoindane (MDAI)), synthetic cannabinoids (e.g. APINACA, JWH-018), synthetic cathinones (e.g. 4-methylethcathinone (4-MEC) and α-pyrrolidinopentiophenone (α –PVP)), phencyclidine-type substances (e.g. methoxetamine (MXE)), phenethylamines (e.g. 2C-E and 25H-NBOMe), piperazines (e.g. benzylpiperazine (BZP) and 1-(3-chlorophenyl) piperazine (mCPP)), plant-based substances (e.g. kratom (mitragyna speciosa Korth), salvia divinorum and khat (Catha edulis)), tryptamines (e.g. α-methyltryptamine (AMT)), and other substances (e.g. 1,3-dimethylamylamine (DMAA)).

Drugwise: New psychoactive substances (NPS) are drugs which were designed to replicate the effects of illegal substances like cannabis, cocaine and ecstasy whilst remaining legal – hence their previous name ‘legal highs’. Drugwise place NPS into four main categories:

• Synthetic cannabinoids – these drugs mimic cannabis and are traded under such names as Clockwork Orange, Black Mamba, Spice and Exodus Damnation. They bear no relation to the cannabis plant except that the chemicals which are blended into the base plant matter act on the brain in a similar way to cannabis.
• Stimulant-type drugs – these drugs mimic substances such as amphetamine, cocaine and ecstasy and include BZP, mephedrone, MPDV, NRG-1, Benzo Fury, MDAI, ethylphenidate.
• ‘Downer’/tranquiliser-type drugs – these drugs mimic tranquiliser or anti-anxiety drugs, in particular from the benzodiazepine family and include Etizolam, Pyrazolam and Flubromazepam.
• Hallucinogenic drugs – these drugs mimic substances like LSD and include 25i-NBOMe, Bromo-Dragonfly and the more ketamine-like methoxetamine.

The effects of NPS vary significantly from drug to drug and, compared to more traditional drugs, we have relatively little information on them. However, there is a growing body of evidence to demonstrate the potential short and long-term harms associated with their use. There have been hospitalisations and deaths linked to NPS...

For Ireland, see the 2017, Country report on new psychoactive substances in Ireland, the latest national report for Ireland, and the Criminal Justice (Psychoactive Substances) Act 2010

For items in our collection, see our 'Emerging trends' webpage

A term of varied usage. In medicine, it refers to any substance with the potential to prevent or cure disease or enhance physical or mental welfare, and in pharmacology to any chemical agent that alters the biochemical physiological processes of tissues or organisms. Hence, a drug is a substance that is, or could be, listed in a pharmacopoeia. In common usage, the term often refers specifically to psychoactive drugs, and often, even more specifically, to illicit drugs, of which there is non-medical use in addition to any medical use. Professional formulations (e.g. "alcohol and other drugs") often seek to make the point that caffeine, tobacco, alcohol, and other substances in common non- medical use are also drugs in the sense of being taken at least in part for their psychoactive effects.

See The drugs wheel web-resource for categories of drugs in a number of countries

ESPAD is a collaborative effort of independent research teams in more than forty European countries and the largest cross-national research project on adolescent substance use in the world. The overall aim with the project is to repeatedly collect comparable data on substance use among 15–16 year old students in as many European countries as possible.

ESPAD publications in library collection

A novel chemical substance with psychoactive properties, synthesized specifically for sale on the illicit market and to circumvent regulations on controlled substances. In response, these regulations now commonly cover novel and possible analogues of existing psychoactive substances. The term was coined in the 1980s.

The analysis of body fluids (such as blood, urine, or saliva) or hair or other tissue for the presence of one or more psychoactive substances. Drug testing is employed to monitor abstinence from psychoactive substances in individuals pursuing drug rehabilitation programmes, to monitor surreptitious drug use among patients on maintenance therapy, and where employment is conditional on abstinence from such substances.

See blood alcohol level for testing specifically for alcohol.

An illicit or licit drug, use of which is regarded as opening the way to the use of another drug, usually one viewed as more problematic.

The use of more than one drug or type of drug by an individual, often at the same time or sequentially, and usually with the intention of enhancing, potentiating, or counteracting the effects of another drug. The term is also used more loosely, to include the unconnected use of two or more drugs by the same person. It carries the connotation of illicit use, though alcohol, nicotine, and caffeine are the substances most frequently used in combination with others in industrialized societies.

Multiple drug use disorder (ICD-11 6C4F.3) is one of the ''Intoxication due to multiple specified psychoactive substances" in ICD-I1, diagnosed only when two or more substances are known to be involved and it is impossible to assess which substance is contributing most to the disorder. The category is also used when the exact identity of some or even all of the substances being used is uncertain or unknown, since many multiple drug users often do not know themselves what they are taking.

Local Drugs Task Forces were established in Ireland following the report of the Ministerial Task Force on Measures to Reduce the Demand for Drugs (1996). There are 14 Local Drug and Alcohol Task Forces, 12 in Dublin, one in Cork and one in Bray. There are also 10 Regional Drug and Alcohol Task Forces. Task Forces include representatives from statutory agencies, the voluntary sector, local communities and public representatives.

Drug and Alcohol Task Force areas:

• Ballymun Local Drugs Taskforce
• Ballyfermot Local Drug and Alcohol Task Force
• Blanchardstown Local Drug & Alcohol Task Force
• Bray Local Drug and Alcohol Task Force
• Clondalkin Drug and Alcohol Task Force
• Cork Local Drug & Alcohol Task Force
• Dublin 12 Local Drugs & Alcohol Task Force
• Dublin North East Drugs & Alcohol Task Force
• Dun Laoghaire Rathdown Drugs Taskforce
• ECRDATF East Coast Regional Drugs Task Force – Wicklow and South Dublin
• Finglas/Cabra Local Drug and Alcohol Task force
• Mid-West Regional Drugs and Alcohol Task Force - Counties Clare and Limerick, and North Tipperary
• Midland Regional Drug and Alcohol Task Force - Counties Laois, Longford, Offaly and Westmeath
• North Dublin Regional Drug and Alcohol Task Force - North Dublin city and county, including the five LDTF areas within these boundaries
• North Eastern Regional Drug and Alcohol Taskforce - Counties Cavan, Louth, Meath and Monaghan
• North Inner City Drugs and Alcohol Task Force
• Northwest Regional Drug and Alcohol Task Force - Counties Donegal, Leitrim and Sligo, and north-west Cavan
• South East Regional Drug and Alcohol Task Force - Counties Carlow, Kilkenny, Waterford and Wexford, and South Tipperary,
• South Western Regional Drugs and Alcohol Task Force - South-west Dublin, west Wicklow and County Kildare, including the six LDTF areas within these boundaries
• Southern Regional Drug and Alcohol Task Force - Counties Cork and Kerry, including the Cork LDTF area
• Tallaght Drug and Alcohol Task Force
• Western Region Drugs & Alcohol Task Force - Counties Galway, Mayo and Roscommon

Drug Task Force websites

8C80 Drug-induced myopathy - Myopathy caused by drugs that ranges from mild myalgias with or without mild weakness to chronic myopathy with severe weakness, to massive rhabdomyolysis with acute renal failure. It could be due to several different mechanisms including direct myotoxicity, immune mediated and indirect muscle damage through drug-induced coma, drug-induced hypokalaemia, drug-induced hyperkinetic states or dystonic states.

8D44.1 Alcoholic myopathy - Myopathy secondary to alcohol use and includes acute and chronic alcoholic myopathy. Several forms have been described: acute necrotizing myopathy, acute hypokalaemic myopathy, chronic alcoholic myopathy, asymptomatic alcoholic myopathy, and alcoholic cardiomyopathy.

The framework for the international control of psychotropic substances is established by the Convention on Psychotropic Substances of 1971 signed in Vienna, Austria. Following the establishment of the Convention on Psychotropic Substances of 1971, a commentary was prepared providing detailed explanation of the various articles and provisions of the convention. The UN Treaty Collection provides information related to the signature, accession, acceptance, approval, formal confirmation and succession by Governments to the United Nations Convention on Psychotropic Substances, 1971 (INCB).

The 1988 Convention against Illicit Traffic in Narcotic Drugs and Psychotropic Substances Convention provides comprehensive measures against drug trafficking, including provisions against money laundering and the diversion of precursor chemicals. It provides for international cooperation through, for example, extradition of drug traffickers, controlled deliveries and transfer of proceedings.

Historical information: International treaties concerned with the control of production and distribution of psychoactive drugs. Early treaties (General Brussels Act, 1889-90, and St Germain-en-Laye Convention of 1912) controlled liquor traffic in Africa in the colonial era. The first treaty dealing with currently controlled substances was the Hague Convention of 1912: its provisions and those of succeeding agreements were consolidated in the Single Convention on Narcotic Drugs (1961; amended by a 1972 Protocol). To this have been added the 1971 Convention on Psychotropic Substances and the 1988 Convention against Illicit Traffic in Narcotic Drugs and Psychotropic Substances (WHO Lexicon of alcohol and drug terms).

For more information on drug laws, see the European Legal Database on Drugs

Any of the range of adverse accompaniments of drug use, particularly illicit drug use. "Related" does not necessarily imply causality. The term was coined by analogy with alcohol-related problem but is less used, since it is drug use itself, rather than the consequences, that tends to be defined as the problem; it can be used to refer to problems at an individual or societal level. In international drug control, drug-related problems are taken into account in setting a level of control for a controlled substance through a WHO assessment of the drug's dependence potential and abuse liability. "Drug problems" is a possible cognate term, but can be confused with "the drug problem", meaning illicit drugs as a policy issue.

Drug abuse or misuse by Drugwise:

Drugs can be used either by swallowing, smoking, injecting or any other way of getting the drug into the blood stream, such as inserting into the anus (often done by heavy cocaine snorters to avoid further damaging their noses) or insufflation – inhaling the drug contained in a fine spray. The terms have different connotations, varying usually on ideas of harm or inappropriate purpose. Abuse and misuse imply that the use is harmful or done in the wrong way. Misuse, as harm, refers to use that is dependent or part of a problematic or harmful behaviour. Those who believe drug taking is wrong, except within a medical context, will tend to use the term misuse to refer to illicit drug taking. The Government, for example, still uses this term, in keeping with their policies that aim to prevent non-medical drug taking. Use by children is regarded as inappropriate and again the terms abuse and misuse often apply, such as in the case of volatile substance abuse which is often harmful and particular to young teenagers. Drug use is used to refer to drug taking that, although it has some risk, is not necessarily wrong or dangerous. The term does not imply that drug taking is wrong and is therefore preferred by many not wishing to value-judge the taking of drugs (Drugwise).

The National Drug Related Deaths Index is a census of drug-related deaths (such as those due to accidental or intentional overdose) and deaths among drug users (such as those due to hepatitis C and HIV) in Ireland. It will also record alcohol-related deaths. The information collected will be used to develop health and social service responses aimed at reducing the number of deaths. The number of drug-related deaths and deaths among drug users is one of the European Union Drugs Agency (EUDA) key indicators to measure the consequences of drug use.

• Non-poisoning deaths:
Deaths in individuals with a history of drug dependency or non-dependent abuse of drugs (ascertained from toxicology results and from Central Treatment List, medical or coronial records) whether or not the use of the drug was directly implicated in the death.

• Poisoning deaths:
Deaths which are directly due to the toxic effect of the presence in the body of one or more drugs and/or other substance(s).

Irish drug-related deaths data

Drug consumption rooms, sometimes known as supervised injecting facilities, are fixed or mobile spaces in which people who inject drugs are provided with sterile injection equipment and can use illicit drugs under the supervision of trained staff. In some countries, consumption rooms also provide a space and equipment to allow non-injecting routes of administration, for example for crack cocaine smokers. Drug consumption rooms exist in several European countries and are usually located in areas where there is an open drug scene and injecting in public places is common. Their primary goal is to reduce morbidity and mortality by providing a safer environment for drug use and training clients in safer forms of drug use. Providing a conduit to other care services and reducing public nuisance may also be an explicit objective.

For more details see the EUDA consumption facilities webpage.

The Misuse of Drugs Acts, 1977 and 1984 and the Regulations made thereunder are the main laws regulating drugs in Ireland. They include controls relating to cultivation, licensing, possession, administration, supply, record-keeping, prescription-writing, destruction and safe custody. They also establish the offences and penalties.
The Misuse of Drugs Act, 1977 (Controlled Drugs) Declaration Order, 1987 extend the list of substances, products and preparations to be controlled for the purposes of the Misuse of Drugs Act, 1977. In 1984 the Criminal Justice Act, 1984 widened the scope of the criminal law and procedures to deal more effectively with serious crime, including serious offences under the Misuse of Drugs Acts.

In November 1993 a new text was introduced to control precursors and essential chemicals, the Misuse of Drugs (Scheduled Substances) Regulations, 1993. With these acts Ireland meets with the obligations relevant to the control of precursors, under the United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances 1988, and under EC Directives 92/109 and EC Regulation 3677/90. The Regulations control production, supply, importation, exportation and possession of the precursors substances.

In 1994 the Criminal Justice Act, 1994 provided for the seizure and confiscation of assets derived from the proceeds of drug trafficking and other offences. It contains provisions related to money laundering and allows for international co-operation in respect of certain criminal law enforcement procedures, the forfeiture of property used in the commission of crime, and related matters. The Criminal Justice (Drug Trafficking) Act, 1996 permits the detention of a person suspected of having committed a drug trafficking offence for up to a maximum of seven days. The Misuse of Drugs Regulations, 1988 sets out the arrangement to facilitate the licence control over the lawful production, supply, importation and exportation of the drugs to which the Misuse of Drugs Acts 1977 and 1984, apply.

The Criminal Justice Act, 1999 amends the Misuse of Drugs Act, 1977 to provide for a new drug related offence. The new section (15A) creates a new offence related to the possession of drugs, with a value of €12 700 or more, for the purpose of sale or supply. A person found guilty of such an offence may be imprisoned for up to life and be subject to an unlimited fine. The Act also provides for a mandatory minimum sentence of ten years in prison. However, the mandaory minimum sentence shall not apply where the court is satisfied that there are exceptional and specific circumstances which would make it unjust in all the circumstances to impose the minimum ten year sentence. In addition, where it is found that addiction was a substantial factor leading to the commission of the offence, the sentence may be reviewed after half of the mandatory period, at which time the court may suspend the remainder of the sentence on any condition it sees fit.
In 2000 new regulations (Customs-free Airport (Extension of Laws) Regulations, 2000) were introduced to extend drug controls under the Misuse of Drugs Acts, 1977 and 1984, and the Irish Medicines Board Act, 1995, to include the Customs free area at Shannon airport. This instrument extends the import/export controls under the Misuse of Drugs Acts, 1977 and 1984 to this area. It also allows Irish Medicines Board to inspect any company within the customs free area at the Customs Free Airport.

The Criminal Justice Act 2006 includes: provisions for creating criminal offences in relation to participation in criminal organisations; proposals to strengthen the provisions on the imposition of the 10-year mandatory minimum sentence for drug trafficking; new offences of supplying drugs to prisoners and provisions in relation to a drug offenders register. The Irish Human Rights Commission has raised a number of concerns about some of the provisions of the Act. (For more information see the Irish National Report 2006)

The Criminal Justice Act 2007 provides for increased Garda detention powers, changes to existing provisions in relation to the right to silence and the introduction of mandatory sentencing for a range of offences. Many of these changes have been introduced in the context of growing concern about drug-related crime. (For more information see the Irish National Report 2007)

The Criminal Justice (Psychoactive Substances) Act 2010 covers substances which are not specifically proscribed under the Misuse of Drugs Acts, but which have psychoactive effects. (For more information see the Irish National Report 2010)

Further resources:

• Chapter one of the Irish National Report for each year provides a summary of new drug and alcohol legislation.
• Library policy and law resource
• See also, Citizens Information – Drug offences

Wikipedia - Regulations (Lists drugs under each schedule)
Legislation provides for the Minister for Health to make regulations scheduling drugs according to their use perceived medical usability and their risk to the public. Additionally, these regulations outline the requirements for distribution and monitoring of the listed substances. The principal regulations are the Misuse of Drugs Regulations 1988 (SI 328/1988) as amended by the Misuse of Drugs (Amendment) Regulations 1993 (SI 342/1993), the Misuse of Drugs (Amendment No. 1) Regulations 1999 (SI 273/1999), the Misuse of Drugs (Amendment) Regulations 2006 (SI 53/2006), the Misuse of Drugs (Amendment) Regulations 2007 (SI 200/2007), the Misuse of Drugs (Amendment) (No. 1) Regulations 2009 (SI 63/2009), the Misuse of Drugs (Amendment) (No. 2) Regulations 2009 (SI 122/2009) and the Misuse of Drugs (Amendment) (No. 2) Regulations 2010 (SI 200/2010).

(1) In the context of psychoactive drugs, the aggregate of polices designed to affect the supply and/or the demand for illicit drugs, locally or nationally, including education, treatment, control, and other programmes and policies. In this context, "drug policy" often does not include pharmaceutical policy (except with regard to diversion to non-medical use), or tobacco or alcohol policy.

(2) In the context of WHO' s Action Programme on Essential Drugs, "national drug policy" refers to a national pharmaceutical policy concerning the marketing, availability, and therapeutic use of medicines. WHO recommends that every country should have such a policy, formulated in the context of a national health policy. The WHO List of Essential Drugs is an effort to assist developing countries to develop a pharmaceutical policy attuned to allocating scarce funds for pharmaceuticals on the basis of health needs rather than market considerations*

* The use of essential drugs. Model List of Essential Drugs (seventh list). Fifth report of the WHO Expert Committee.Geneva, World Health Organization. 1992 (WHO Technical Report Series. No.825).

See all Irish policy documents

EUDA - EU policy and law and Alternatives to coercive sanctions webpage

The European Union Drugs Agency (EUDA) is the leading authority on illicit drugs in Europe. Based in Lisbon, Portugal, we provide independent scientific evidence and analysis on all aspects of this constantly changing threat to individual lives and wider society. Our work contributes to EU and national policies to protect Europe's citizens from drug-related harms. We are an agency of the European Union.

The EUDA’s organisation consists of a Directorate to manage the agency, two statutory bodies (Management Board and Scientific Committee) to advise and assist in the decision making process, and, finally, the various working units (which comprises the majority of the EUDA’s staff) to run the agency and ultimately deliver its products and services.

Cooperation with EU institutions, the Reitox network (30 national drug monitoring centres), candidate and potential candidates to the EU, European Neighbourhood Policy (ENP) area countries,and regional and international organisations was an important activity for the EUDA’s predecessor, the EMCDDA, starting in 1993.

A psychoactive substance, the production, sale, or use of which is prohibited. Strictly speaking, it is not the drug that is illicit, but its production, sale, or use in particular circumstances in a given jurisdiction (see controlled substances). "illicit drug market", a more exact term, refers to the production, distribution, and sale of any drug outside legally sanctioned channels.

An illicit drug is defined as any drug which is illegal to possess or use or any legal drug used in an illegal manner, for example: a drug obtained on prescription but given or sold to another person to use; glue or petrol which is sold legally, but is used in a manner that is not intended, such as inhaling fumes; stolen pharmaceuticals sold on the black market (e.g. Pethidine) (Australian Government).

A drug that is legally available by medical prescription in the jurisdiction in question, or, sometimes, a drug legally available without medical prescription.

The National Drug Treatment Reporting System (NDTRS) is an epidemiological database on treated drug and alcohol misuse in Ireland. It was established in 1990 in the Greater Dublin Area and was extended in 1995 to cover all areas of the country. Since 2004, clients reporting alcohol as their main problem drug have been recorded by the system.

NDTRS Links:

• NDTRS publications and interactive treatment tables
• NDTRS protocol for data collection
• How NDTRS data is collected and used

The NDTRS uses the following definition of treatment in its 2022 collection protocol:

• any activity that aims to improve the psychological, medical and social state of individuals;
• one or more of the following: medication (detoxification, methadone reduction and substitution programmes), addiction counselling, group therapy, psychotherapy and/or life skills training;
• treatment in residential and non-residential settings;
• treatment in prison.

The National Drug-Related Deaths Index (NDRDI) is a census of drug-related deaths (such as those due to accidental or intentional overdose) and deaths among drug users (such as those due to hepatitis C and HIV) in Ireland. It also records alcohol-related deaths.

Data is collected from a number of sources, including:
• The Coroner Service;
• The General Mortality Register;
• The Central Treatment List;
• HIPE

The information is used to develop health and social service responses aimed at reducing the number of deaths.

More about the HRB NDRDI

Link: Latest NDRDI publications

Performance and image enhancing drugs (PIEDs) are taken by people who wish to improve their physical appearance and/or enhance their strength and sporting performance.

Possible benefits include increasing the size and definition of muscles, reducing body fat, increasing strength/endurance and helping the body recover from injury. These benefits can increase a user’s confidence and self-esteem which may lead to them becoming psychologically dependent on these drugs. The most widely used type of PIED are anabolic steroids however this group also includes peptides and hormones such as androstenedione, human growth hormone, erythropoietin, diuretics, and various stimulants...

See also, steroid

A generic term for substances that modify normal behaviour. Examples can be found in the 1971 UN Convention on Psychotropic Substances. Many are subclassified as stimulants or hallucinogens, but the term can also include sedatives, tranquillisers and hypnotics. Psychotropic drugs are differentiated from narcotics, which are more correctly known as narcotic analgesics.

From WHO Lexicon of alcohol and drug terms - Psychotropic: In its most general sense, a term with the same meaning as "psychoactive'', i.e. affecting the mind or mental processes. Strictly speaking, a psychotropic drug is any chemical agent whose primary or significant effects are on the central nervous system. Some writers apply the term to drugs whose primary use is in the treatment of mental disorders—anxiolytic sedatives, antidepressants, antimanic agents, and neuroleptics. Others use the term to refer to substances with a high abuse liability because of their effects on mood, consciousness, or both—stimulants, hallucinogens, opioids, sedatives/hypnotics (including alcohol), etc. In the context of international drug control, "psychotropic substances" refers to substances controlled by the 1971 Convention on Psychotropic Substances (see conventions, international drug).

In treatment, the primary drug is defined as the drug that causes the client the most problems at the start of treatment. This is usually based on the request made by the clients and (or) on the diagnosis made by a therapist, commonly using international standard instruments (e.g. ICD-11; DSM-V) or clinical assessment. This item is of central importance and it should be collected for every client. 

Secondary drugs are those drugs used in addition to the primary drug, and are substances that cause problems for the client and/or change the nature of the problem as assessed by the client and the therapist.

For more details, see EMCDDA Treatment Demand Indicator Protocol version 3.0