F19.7 ICD-10-CA subcategory: Mental and behavioural disorders due to multiple drug use and use of other psychoactive substances, residual and late-onset psychotic disorder

Note

• A disorder in which alcohol- or psychoactive substance-induced changes of cognition, affect, personality, or behaviour persist beyond the period during which a direct psychoactive substance-related effect might reasonably be assumed to be operating. Onset of the disorder should be directly related to the use of the psychoactive substance. Cases in which initial onset of the state occurs later than episode(s) of such substance use should be coded here only where clear and strong evidence is available to attribute the state to the residual effect of the psychoactive substance. Flashbacks may be distinguished from psychotic state partly by their episodic nature, frequently of very short duration, and by their duplication of previous alcohol- or other psychoactive substance-related experiences.
• This category should be used when two or more psychoactive substances are known to be involved, but it is impossible to assess which substance is contributing most to the disorders. It should also be used when the exact identity of some or even all the psychoactive substances being used is uncertain or unknown, since many multiple drug users themselves often do not know the details of what they are taking.From F19 Mental and behavioural disorders due to multiple drug use and use of other psychoactive substances
• This block contains a wide variety of disorders that differ in severity and clinical form but that are all attributable to the use of one or more psychoactive substances, which may or may not have been medically prescribed. The third character of the code identifies the substance involved, and the fourth character specifies the clinical state. The codes should be used, as required, for each substance specified, but it should be noted that not all fourth-character codes are applicable to all substances.Identification of the psychoactive substance should be based on as many sources of information as possible. These include self-report data, analysis of blood and other body fluids, characteristic physical and psychological symptoms, clinical signs and behaviour, and other evidence such as a drug being in the patient's possession or reports from informed third parties. Many drug users take more than one type of psychoactive substance. The main diagnosis should be classified, whenever possible, according to the substance or class of substances that has caused or contributed most to the presenting clinical syndrome. Other diagnoses should be coded when other psychoactive substances have been taken in intoxicating amounts (common fourth character .0) or to the extent of causing harm (common fourth character .1), dependence (common fourth character .2) or other disorders (common fourth character .3-.9).Only in cases in which patterns of psychoactive substance-taking are chaotic and indiscriminate, or in which the contributions of different psychoactive substances are inextricably mixed, should the diagnosis of disorders resulting from multiple drug use (F19.-) be used.From F10-F19 Mental and behavioural disorders due to psychoactive substance use