A Descriptive Study of Hallucinogen and Inhalant Detoxification Admissions From 2006 to 2022

Abstract

Background:

Detoxification is often identified as treating drug withdrawal. All drug classes except hallucinogens and inhalants include withdrawal as diagnostic criteria for a substance use disorder diagnosis. This descriptive study provides an analysis of detoxification admissions for individuals with hallucinogens or inhalants as their primary substance.

Objectives:

This research aimed to explore the characteristics of these detoxification admissions, focusing on demographics, substance use patterns, and treatment characteristics.

Design:

This retrospective study used annual cross-sectional data.

Methods:

Using the Treatment Episode Dataset Admissions 2006 to 2022 file, data from 8919 detoxification admissions over a 17-year period from publicly funded treatment facilities in the United States were examined.

Results:

During the 17-year period, n = 6761 and n = 2158 detoxification treatment episode admissions had the primary substance hallucinogens and inhalants, respectively. Polysubstance use was prevalent among both samples, with 66% among the hallucinogen sample and 48% among the inhalant sample, with alcohol, cannabis, and cocaine/crack being the most commonly co-used substances. A total of 2872 cases were identified as only having hallucinogens and/or inhalants without other drug classes as reported substances during admission.

Conclusion:

These preliminary findings highlight detoxification admissions among individuals with primary substances that do not meet diagnostic criteria for withdrawal. More research is needed to better understand the context of detoxification among individuals with hallucinogens or inhalants as their primary substance.

Introduction

In the United States (U.S.), approximately 3% and 1% of the population used a hallucinogen or an inhalant, respectively, ¹ with 0.2% of individuals having a hallucinogen use disorder and 0.1% having an inhalant use disorder in 2023. ² Withdrawal is 1 of 11 symptoms used for a person to meet the criteria for a substance use disorder (SUD) according to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision. ³ Withdrawal diagnoses are present in drug classes such as alcohol and tobacco, but there are no such diagnostic criteria for an SUD with hallucinogens or inhalants. ³ While the International Classification of Diseases, 10th Revision, Clinical Modification has withdrawal codes for other drug classes (eg, F12.13 Cannabis abuse with withdrawal), no such codes exist for hallucinogens and inhalants. ⁴

This short report builds on previous studies that have described the experience of inhalant withdrawal,^5-9 by focusing on the only 2 drug classes without a diagnostically defined withdrawal syndrome: hallucinogens and inhalants per the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision. ³ Regarding hallucinogen withdrawal, Halpern & Corey stated, “Hallucinogen withdrawal is occasionally mentioned by those attempting to sell “detoxification” strategies or other interventions to an unwitting public, but because hallucinogens in general do not induce physiological dependence, there is no classic withdrawal syndrome.” ¹⁰ Detoxification is described as primarily managing withdrawal to reduce the effects of substances on an individual.^11,12 Considering the absence of a diagnostically recognized withdrawal syndrome for hallucinogens or inhalants, and the role of clinical detoxification settings in managing withdrawal symptoms, this descriptive study explored detoxification admissions, with hallucinogens or inhalants as their primary substance (initial substance prompting admission) from 2006 to 2022. Prevalence, demographic characteristics, and polysubstance use were examined among these treatment episodes.

Materials and Methods

Data

This retrospective cross-sectional study using annual data, examined the Treatment Episode Dataset Admissions 2006 to 2022 file, which describes treatment episode admissions (not individual people) from SUD treatment facilities that receive public funds in the U.S. ¹² The dataset contains 31 152 649 cases. After selecting only detoxification service/settings as indicated in the dataset which included [a] Detox, 24-hour, hospital inpatient (ie, hospital detoxification for severe medical-associated withdrawal), [b] Detox, 24-hour, free-standing residential (ie, non-hospital residential detoxification for withdrawal), and [c] Ambulatory, detoxification (ie, outpatient detoxification for withdrawal), ¹² the sample size was reduced to 6 435 314. After selecting hallucinogens, inhalants, and phencyclidine (PCP) as the primary substance (see supplemental Table 1 for substances identified as hallucinogens and inhalants in the dataset) and removing cases from U.S. territories (<5 cases), the final sample size for the current study was N = 8919. This includes n = 6761 treatment episodes with hallucinogens and n = 2158 treatment episodes with inhalants as the primary substance.

Measures

Included variables are age, hallucinogens or inhalants only, mental health disorder, prior treatment episode, race and ethnicity, region, sex, treatment type, secondary substance, and tertiary substance. Age is a categorical variable including the following age groups 12 to 17 years, 18 to 20 years, 21 to 24 years, 25 to 29 years, 30 to 34 years, 35 to 39 years, 40 to 44 years, 45 to 49 years, 50 to 54 years, and 55 years and older. Hallucinogens or inhalants only describe cases that include the 2 drug classes as their primary, secondary, and tertiary substances. Cases were identified as hallucinogens and inhalants only if their secondary and tertiary substances were categorized as hallucinogens, inhalants, or none. Essentially, these are cases in which only hallucinogens or inhalants were documented, to the exclusion of all other drug classes. Mental health disorder described if the case had a co-occurring mental health disorder. Prior treatment episode described if the case had any prior substance use treatment. Race and ethnicity contain the following categories: American Indian or Alaska Native, Black or African American, Hispanic or Latino Any Race, White, and Another Race or Ethnicity. Region includes Midwest, Northeast, South, and West. Sex includes Female and Male as values. Treatment type includes Detox, 24-hour, hospital inpatient, Detox, 24-hour, free-standing residential, and Ambulatory, detoxification. Secondary and tertiary substances included substances such as alcohol, and cocaine/crack.

Analysis

The University of North Carolina at Chapel Hill Institutional Review Board considered study procedures not human subjects research because de-identified publicly available data were used. The package ggplot2 ¹³ in R Version 4.3.3 ¹⁴ and SPSS Version 29 ¹⁵ were used. Focusing on descriptive statistics,^16,17 this study examined the counts and percentages of study variables.

Results

Considering the total of 6 435 314 detoxification cases in the dataset before the sample selection criteria, hallucinogens as the primary substance accounted for 0.1% of cases annually (2006-2022). Similarly, inhalants, as the primary substance, accounted for 0.0% of cases annually (2006-2022), except in 2010 and 2016, when they accounted for 0.1%. Descriptive statistics of both study samples may be found in Table 1.

Table 1.

Sample Characteristics.

Characteristics	Hallucinogens as primary substance		Inhalants as primary substance
	n	%	n	%
Total	6761	100.0	2158	100.0
Region
Midwest	1082	16.0	340	15.8
Northeast	2238	33.1	331	15.3
South	2323	34.4	813	37.7
West	1118	16.5	674	31.2
Treatment setting
24-Hour free-standing residential detoxification	6095	90.1	1915	88.7
24-Hour hospital inpatient detoxification	485	7.2	139	6.4
Ambulatory detoxification	181	2.7	104	4.8
Age
12-17 years	278	4.1	94	4.4
18-20 years	551	8.1	171	7.9
21-24 years	908	13.4	227	10.5
25-29 years	1409	20.8	358	16.6
30-34 years	1233	18.2	350	16.2
35-39 years	954	14.1	322	14.9
40-44 years	620	9.2	205	9.5
45-49 years	421	6.2	188	8.7
50-54 years	215	3.2	132	6.1
55 years and older	172	2.5	111	5.1
Sex
Female	2135	31.6	687	31.8
Male	4624	68.4	1471	68.2
Missing	2	0.0	0	0.0
Race and ethnicity
American Indian or Alaska Native	87	1.3	103	4.8
Black or African American	2834	41.9	156	7.2
Hispanic or Latino any race	831	12.3	266	12.3
White	2731	40.4	1551	71.9
Another race or ethnicity	188	2.8	52	2.4
Missing	90	1.3	30	1.4
Co-occurring mental health disorder
No	2871	42.5	980	45.4
Yes	1898	28.1	757	35.1
Missing	1992	29.5	421	19.5
Prior treatment episode
No prior treatment episode	2332	34.5	873	40.5
One prior treatment episode	1003	14.8	401	18.6
Two prior treatment episodes	525	7.8	206	9.5
Three prior treatment episodes	382	5.7	113	5.2
Four prior treatment episodes	208	3.1	74	3.4
Five prior treatment episodes	706	10.4	220	10.2
Missing	1605	23.7	271	12.6
Hallucinogen or inhalants only a	1865	27.6	1007	46.7

a

Hallucinogens or Inhalants only: Hallucinogens, inhalants, or none were selected as the secondary and tertiary substances.

Hallucinogens as Primary Substance

Among the sample with hallucinogens as their primary substance (n = 6761), the most reported secondary substances included cannabis (n = 1462; 21.6%), alcohol (n = 1184; 17.5%), and cocaine/crack (n = 732; 10.8%). The most reported tertiary substances in this sample include alcohol (n = 639; 9.5%), cannabis (n = 524; 7.8%), and cocaine/crack (n = 318; 4.7%). Considering the presence of a secondary substance, polysubstance use was reported among 66% of this sample (n = 4467). Regarding the primary substance, 55.5% (n = 3755) of the sample had PCP listed, whereas 44.5% (n = 3006) of the sample had hallucinogens listed. Non-Hispanic Black or African Americans were the most prevalent racial/ethnic group at 41.9%, PCP primarily drove this as PCP was the primary substance among n = 2346 treatment episodes involving non-Hispanic Black or African Americans. Figure 1 shows the annual counts of cases with hallucinogens as their primary substance.

Figure 1.

Annual counts of treatment episodes in detoxification with hallucinogens as the primary substance: 2006 to 2022.

Inhalants as Primary Substance

Among the sample with inhalants as their primary substance (n = 2158), the most prevalent secondary substances included alcohol (n = 360; 16.7%), cannabis (n = 259; 12.0%), and cocaine/crack (n = 117; 5.4%). The most prevalent tertiary substances included cannabis (n = 124; 5.7%), alcohol (n = 104; 4.8%), and cocaine/crack (n = 45; 2.1%). Polysubstance use was reported in 48% of this sample (n = 1045). Figure 2 shows the annual counts of cases with inhalants as their primary substance.

Figure 2.

Annual counts of treatment episodes in detoxification with inhalants as the primary substance: 2006 to 2022.

Discussion

Building on prior research describing the experience of inhalant withdrawal,^5-9 this study examined detoxification admissions among the only 2 drug classes without a diagnostically defined withdrawal syndrome: hallucinogens and inhalants, based on the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision criteria. ³ The number of individuals with hallucinogens or inhalants as their primary substance in detoxification accounted for approximately 0.1% (n = 8919), of all detoxification admission treatment episodes in the dataset. An even smaller number of individuals only had hallucinogens or inhalants as the substance(s) (n = 2872) during admission. In the sample with hallucinogens as their primary substance, non-Hispanic Black or African Americans were the most prevalent racial/ethnic group, which was primarily driven by PCP. A study from 1998 identified the duration and peak period of withdrawal related to PCP or psychedelics as days to weeks.^18,19

The breadth of diverse hallucinogenic chemical derivatives and inhalant-viable substances enables greater difficulty in capturing the full range of withdrawal symptoms. These classes of substances also fall into contrasting regulatory spectrums. On one end, some hallucinogens are federally classed as Schedule I drugs under the Controlled Substances Act, while others are not. Inhalants can be modified from everyday items found in households. It is also worth noting that some commercially available items can also create a hallucinogenic response, such as the presence of lysergic acid amide. ²⁰ Study limitations must be considered alongside these findings, such as the dataset only capturing treatment in facilities that receive public funds. Another limitation is that treatment episodes are the unit of analysis. Other future studies may examine these substances being co-used with other primary substances among individuals entering detoxification services. Overall, these preliminary findings highlight detoxification admissions among individuals with primary substances that do not meet diagnostic criteria for withdrawal. More research is needed to understand the contextual factors that influence detoxification admissions among persons primarily using hallucinogens and inhalants.

Supplemental Material

sj-docx-1-sat-10.1177_29768357251393025 – Supplemental material for A Descriptive Study of Hallucinogen and Inhalant Detoxification Admissions From 2006 to 2022

Supplemental material, sj-docx-1-sat-10.1177_29768357251393025 for A Descriptive Study of Hallucinogen and Inhalant Detoxification Admissions From 2006 to 2022 by G. Rose Geiger and Orrin D. Ware in Substance Use: Research and Treatment