How to Assess the ICD-10 Codes for Hallucinogen Substance Use Disorder

A study from medical researchers at the Columbia University Mailman School of Public Health found that over 5.5 million U.S. citizens consumed a hallucinogen in 2019. This figure accounted for 2.2% of the population and marked a 0.5% increase from 2002 in overall usage among those 12 and older. LSD use rose 3.1% during the same period for individuals aged 18 to 25.

More recently, researchers at the University of Michigan Institute for Social Research discovered that for adults under 30, the use of hallucinogens other than LSD jumped from 3.4% in 2018 to 6.6% in 2021, while LSD use held steady at around 4%. Psilocybin, the active ingredient in “magic mushrooms,” was the most popular. While the study did not differentiate between therapeutic and recreational use, researchers noted that it can be risky to use psychotropic drugs, even therapeutically, without medical supervision.

We’ll explain the current patterns of hallucinogenic substance use in the United States and how providers should use ICD-10 codes to document the various associated states of the disorder. 

The Current State of Substance Use Disorders in the US

The current opioid epidemic started in the early 1990s and has been described in TIME magazine as the worst addiction crisis in U.S. history. The epidemic has drawn comparisons to China’s national opioid epidemic in the late 1890s. Both crises started with an amplification of the therapeutic benefits of opioids that failed to adequately consider their potential for addiction. 

Since most illicit drug users are reticent to speak openly about their use habits, it’s difficult to determine the full scope of the current addiction crisis in the U.S. Several credible studies, however, show that drug use is considerably higher than it has ever been. 

Quest Diagnostics, a leading workforce drug testing provider, reports that it started seeing upticks in positive drug tests in 2016 after years of decline. In 2015, of 9.5 million urine tests the company analyzed, 4% came back positive, up slightly from the positivity rate two years earlier. 

Increases in Psychotropic Drug Use During the Pandemic

According to U.S. health officials, the COVID-19 pandemic worsened the drug crisis. Between autumn 2020 and autumn 2021, the nation documented more than 100,000 overdose deaths, the highest number on record and a 50% increase over the previous two years. 

Reports from this time showed considerable increases in marijuana and hallucinogen use among 19-to-30-year-olds. Positive drug screens for fentanyl, cocaine, heroin, and methamphetamine climbed during the pandemic. Cannabis and alcohol use also substantially increased, particularly among younger users.

Drug use undeniably increased across the board during the pandemic. However, data concerning the most commonly used hallucinogens, like psilocybin and LSD, remains somewhat foggy. These two compounds typically require special testing kits to detect them in chemical screenings. Moreover, the psychedelic chemical in hallucinogenic mushrooms exits the system quickly, within 24 hours, while LSD is identifiable no longer than four days after use in a urine analysis. 

The Rise of Microdosing

Microdosing, ingesting small “sub-hallucinogenic” doses of psychedelic drugs like LSD and psilocybin mushrooms, to improve mental health became a growing trend in the years before the pandemic, particularly among the tech community in Silicon Valley. 

Microdosing proponents often cite a Johns Hopkins study reporting that psilocybin may help treat major depression. A randomized, double-blind trial published in The Journal of Psychology showed evidence of psilocybin substantially decreasing depression and anxiety symptoms in patients battling life-threatening cancer. 

Since hallucinogen abuse can be challenging to both diagnose and treat, providers need to understand the associated ICD-10 codes discussed below. 

Now that we’ve given an overview of the current landscape for psychedelic drug use, we’ll explore how ICD-10 medical coding helps providers diagnose the various forms of hallucinogenic use disorder more concisely. 

Interpreting ICD-10 Codes of Hallucinogenic Substance Use Disorder

In the current version of the World Health Organization’s International Classification of Diseases 10th Revision, the F16 block of codes represents the mental health and behavioral problems attributable to hallucinogenic substance use disorder. The subdivisions under the F16 ICD-10 diagnostic codes are similar to the several other ICD-10 use disorder codes that cover alcohol, cocaine, and opioid consumption. 

The fourth digit in the code, zero, refers to the patient’s condition — acute intoxication — after consuming the psychoactive substance. The clinician uses this portion of the code to document disturbances in consciousness levels, perception, and any loss of psychomotor function. These symptoms and complications relate to the pharmacological effects of hallucinogens shortly after ingesting the problem drug.

The digit marked by .1 indicates the pattern of psychotropic substance abuse that contributed to any observable ill-health effects after consuming the psychotropic drug. The .2 within the ICD-10’s alphanumeric code marks the patient’s state of drug dependence. Any documented withdrawal states are shown in the fourth common character by .4.

If .5 is present in the code, this signifies a cluster of psychotic phenomena that occurs after ingesting the psychotropic drug. This state is typically characterized by intense hallucinations and paranoid delusions. If .6 is visible in the code’s fourth digit, it denotes amnesic syndrome or a chronic memory impairment. 

The .7 in ICD-10 codes the fourth character signifies late-onset psychotic disorder. Clinicians use this code when flashbacks or other hallucinations start to occur beyond the normal intoxication phase. The digit .8 refers to other mental and behavioral disorders. If .9 is present in the fourth alphanumeric position, it indicates an unspecified mental or behavioral disorder.

The FC16 Codes for Hallucinogenic Substance Use

The F16 hallucinogenic substance use disorder codes cover a diverse range of psychotropic drugs, including phencyclidine or PCP. The medical codes break down as follows:

F16.10: Hallucinogenic substance use, unspecified, without hallucinogenic-induced disorder

This ICD-10 code indicates use without other specified disorders. This should be used for a patient who has tried the drug for the first time or accidentally ingested the problem substance. 

F16.11: Hallucinogenic substance use, unspecified, with hallucinogenic-induced psychotic disorder

F16.11 is similar to F16.10 but includes symptoms of psychosis.

F16.12: Hallucinogenic substance abuse

Abuse in this context refers to a habitual pattern of hallucinogenic drug use.

Subcategories include:

  • F16.120 – With intoxication
  • F16.121 – With intoxication with delirium
  • F16.122 – With intoxication including perceptual disturbance
  • F16.129 – With intoxication, unspecified

F16.14: Hallucinogenic substance abuse, unspecified, with hallucinogenic substance-induced mood disorder

Clinicians designate this code when hallucinogenic substance use leads to mood disturbances.

F16.15: Hallucinogenic substance dependence

This alphanumeric combination refers to a patient who has become dependent on the problematic substance.

Subcategories include:

  • F16.150 – With intoxication
  • F16.151 – With intoxication with delirium
  • F16.159 – With intoxication, unspecified

F16.18: Hallucinogenic substance abuse with hallucinogenic substance-induced disorder

Clear signs of intoxication should be present under this classification. 

Subcategories include:

  • F16.180 – With anxiety disorder
  • F16.183 – With withdrawal
  • F16.188 – With other hallucinogenic substance-induced disorder

F16.19: Hallucinogenic substance use, unspecified, with other hallucinogenic substance-induced disorder

Unspecified hallucinogenic substance use with other drug-induced disorders not classified elsewhere should be marked with this code.

F16.20: Hallucinogenic substance abuse, uncomplicated

Hallucinogenic substance abuse without complications or additional disorders is indicated by F16.20.

F16.21: Hallucinogenic substance dependence, uncomplicated

Providers should use this code to document uncomplicated hallucinogenic substance dependence.

F16.22: Hallucinogenic substance dependence with intoxication

As is self-evident, the patient should be dependent, with symptoms of intoxication.

Subcategories include:

  • F16.220 – With intoxication delirium
  • F16.221 – With intoxication and perceptual disturbance
  • F16.229 – With intoxication, unspecified

F16.24: Hallucinogenic substance use, unspecified, with hallucinogenic substance-induced mood disorder

This code indicates unspecified hallucinogenic substance use leading to mood disturbances.

F16.25: Hallucinogenic substance dependence with hallucinogenic substance-induced psychotic disorder

Symptoms of psychosis should be present under this ICD-10 classification.

Subcategories include:

  • F16.250 – With hallucinations
  • F16.251 – With delusions
  • F16.259 – Unspecified

F16.28: Hallucinogenic substance dependence with other hallucinogenic substance-induced disorders

Clinicians use this code for any substance-induced orders not listed above.

Subcategories include:

  • F16.280 – With anxiety disorder
  • F16.283 – With withdrawal
  • F16.288 – With other phencyclidine-induced disorder

F16.29: Hallucinogenic substance dependence with other hallucinogenic substance-induced disorder, unspecified

This sequence indicates unspecified hallucinogenic substance dependence with one or more unspecified hallucinogenic substance-induced disorders.

F16.90: Hallucinogenic substance use, unspecified, without hallucinogenic substance-induced disorder

For a general code for unspecified hallucinogenic substance use without a related disorder, providers should use F16.90.

F16.92: Hallucinogenic substance abuse with intoxication

Signs of intoxication should be present under this classification.

Subcategories include:

  • F16.920 – With delirium
  • F16.921 – With perceptual disturbance
  • F16.929 – Unspecified

F16.94: Hallucinogenic substance abuse, with hallucinogenic substance-induced mood disorder

This code refers to hallucinogenic substance abuse that results in mood disorders.

F16.95: Hallucinogenic substance dependence with intoxication

Both dependence and intoxication must be present. 

Subcategories include:

  • F16.950 – With delirium
  • F16.951 – With perceptual disturbance
  • F16.959 – Unspecified

F16.98: Hallucinogenic substance abuse with other hallucinogenic substance-induced disorder

This classification is reserved for abnormal symptoms. 

Subcategories include:

  • F16.980 – With anxiety disorder
  • F16.983 – With withdrawal
  • F16.988 – With other specified hallucinogenic substance-induced disorders

F16.99: Hallucinogenic substance use, unspecified, with other hallucinogenic substance-induced disorder, unspecified

Unspecified hallucinogenic substance use with unspecified other hallucinogenic substance-induced disorder should be marked by F16.99.

Need More Accurate and Efficient 1CD-10 Medical Coding?

The above ICD-10 codes give healthcare providers a precise framework for categorizing and identifying the various states of hallucinogenic substance use disorder. If your clinic or health agency struggles with coding inaccuracies and navigating the complexity of the ICD-10 classification systems, AutoNotes can help.

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