In pre-employment screenings, the criminal justice system, sports medicine, and screening and confirming reasons in individuals with physical and mental problems, illegal drug testing is employed. Depending on the indication, the types of medications evaluated and the methods utilized differ. Although hair and sweat are increasingly engaged in medico-legal situations and child protection issues, this article focuses mostly on blood, urine, and oral fluids, which are more typically used in mental health settings.
Illegal drug usage is using a legally restricted substance in a way that goes against a culture’s moral or customary standards. Over ten percent of adults aged 16 to 59 had used illicit substances in the previous year in 2005/2006. (Home Office 2006). Because of the spike in cocaine use, the use of ‘Class A substances’ (typically heroin or cocaine) increased by almost 3%. In the previous year, nearly 25% of young adults aged 16 to 24 reported using illicit drugs; 17 percent of youngsters aged 11–15 reported using drugs in the previous year, and 9% in the last month (Home Office 2006). In mental health services, the prevalence is substantially higher: 25 percent of adult in-patients and 50 percent of teenage in-patients have an illegal substance use issue (Reference Crome, Bloor, and ThomCrome 2006).
Types of medication analysis and quality control
Drug analysis can be classed as largely utilized for screening or primarily used for confirmation (Box 1). A very sensitive screening approach should be used first, followed by a highly specific confirmatory test for samples that are found to be positive. Immunoassays are used in most screening processes because they allow for large-scale screening and quick detection (Reference Armbruster, Schwarzhoff, and HubsterArmbruster 1993). They are thus perfect for home-testing kits, near-patient tests, or point-of-care screenings, as the specimen may be tested, the data obtained, and the interpretation done without the need for specialized laboratory conditions. Cloned enzyme donor immunoassay (CEDIA), enzyme-multiplied immunoassay method (EMIT), fluorescence polarization immunoassay, immunoturbidimetric assay, and radioimmunoassay are all immunoassay techniques.
Drug testing is a three-step process that includes collecting samples, analyzing them in the lab, and interpreting the results based on the indication (Reference Saxon, Calsyn, and HaverSaxon 1988).
Depending on the needs in various situations, the types of drugs tested for and the procedures utilized vary. The presence of a substance in a specimen does not imply that it was used illegally, and it could indicate contamination that was either unintentional or unavoidable. Many British banknotes, for example, that have been used by drug users are tainted with cocaine, which can be identified in the hands of bank employees. Similarly, police officers raiding illegal drug warehouses are likely to be exposed to aerosols and powder.
Urine remains the most regularly used specimen in mental health settings. Drug-testing kits on the market can detect up to ten different drugs, including barbiturates. Barbiturate abuse is uncommon. Thus testing is rarely required unless there is a clinical suspicion of abuse. Amphetamine, methamphetamine, 3, 4-methylenedioxymethamphetamine (MDMA or “ecstasy”), cocaine, cannabis, methadone, opiates, benzodiazepines, and tricyclic antidepressants are among the other nine substances.
Illicit drug use and detection have significant implications for mental health services in general (Box 4). Psychiatrists must be more aggressive in seeking tests in a scientifically sound manner based on drug detection windows, which will vary depending on the specimen and drug in question. Although urine remains the most regularly used specimen, oral fluids offer numerous benefits and should be evaluated more frequently. Ideally, specimen analysis should focus on metabolites rather than the parent drug, as the latter could indicate contamination rather than ingestion.