Patterns of Substance Use and Associations with Mental, Physical, and Social Functioning: A Latent Class Analysis of a National Sample of U.S. Adults Ages 30-80

Measurement Properties of the Patient Health Questionnaire-15 and Somatic Symptom Scale-8: A Systematic Review and Meta-Analysis

Importance

The subjective experience of somatic symptoms is a key concern throughout the health care system. Valid and clinically useful instruments are needed.

Objective

To evaluate the measurement properties of 2 widespread patient-reported outcomes: the Patient Health Questionnaire-15 (PHQ-15) and Somatic Symptom Scale-8 (SSS-8).

Data Sources

Medline, PsycINFO, and Web of Science were last searched February 1, 2024.

Study Selection

English-language studies reporting estimates pertaining to factor analysis, taxometric analysis, internal consistency, construct validity, mean scores in relevant groups, cutoffs, areas under the receiver operating characteristic curves (AUROCs), minimal clinically important difference, test-retest reliability, or sensitivity to change.

Data Extraction and Synthesis

Search hits were reviewed by independent raters. Cronbach α, Pearson r, means, and between-group effect sizes indicative of sensitivity to change were pooled in random-effects meta-analysis. Study quality was assessed using 3 instruments. Reporting followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 reporting guideline.

Main Outcomes and Measures

Comprehensive overview of evidence pertaining to the measurement properties of the PHQ-15 and SSS-8.

Results

A total of 305 studies with 361 243 participants were included. Most concerned routine care (178 studies) and the general population (27 studies). In factor analyses, both scales reflected a combination of domain-specific factors (cardiopulmonary, fatigue, gastrointestinal, pain) and a general symptom burden factor. The pooled PHQ-15 α was 0.81 (95% CI, 0.80-0.82), but with low item-total correlations for items concerning menstrual problems, fainting spells, and sexual problems (item-total correlations <0.40), and the SSS-8 α was 0.80 (0.77-0.83). Pooled correlations with other measures of somatic symptom burden were 0.71 (95% CI, 0.64-0.78) for the PHQ-15 and 0.82 (95% CI, 0.72-0.92) for the SSS-8. Reported AUROCs for identification of somatoform disorders ranged from 0.63 (95% CI, 0.50-0.76) to 0.79 (95% CI, 0.73-0.85) for the PHQ-15 and from 0.71 (95% CI, 0.66-0.77) to 0.73 (95% CI, 0.69-0.76) for the SSS-8. The minimal clinically important difference on both scales was 3 points. Test-retest reliability could not be pooled and was inconsistent for the PHQ-15 (PHQ-15: r = 0.65-0.93; ICC, 0.87; SSS-8: r = 0.996, ICC = 0.89). The PHQ-15 showed tentative sensitivity to change (g = 0.32; 95% CI, 0.08-0.56), but data for the SSS-8 were lacking.

Conclusions and Relevance

In this systematic review and meta-analysis, findings supported use of the PHQ-15 and SSS-8 for the assessment of symptom burden, but users should be aware of the complex, multifactorial structures of these scales. More evidence is needed concerning longitudinal measurement properties.

Seeking order in patterns of polysubstance use

PURPOSE OF REVIEW

This review provides an overview of recent developments in understanding polysubstance use patterns across the lifespan, and advances made in the prevention and treatment of harm arising from polysubstance use.

RECENT FINDINGS

A comprehensive understanding of the patterns of polysubstance use is hampered by heterogeneity across study methods and types of drugs measured. Use of statistical techniques such as latent class analysis has aided in overcoming this limitation, identifying common patterns or classes of polysubstance use. These typically include, with decreasing prevalence, (1) Alcohol use only; (2) Alcohol and Tobacco; (3) Alcohol, Tobacco, and Cannabis; and finally (4) a low prevalence, Extended Range cluster that includes other illicit drugs, Novel Psychoactive Substances (NPS), and nonmedical prescription medications.

SUMMARY

Across studies, there are commonalities present in clusters of substances used. Future work that integrates novel measures of polysubstance use and leverages advances in drug monitoring, statistical analysis and neuroimaging will improve our understanding of how and why drugs are combined, and more rapidly identify emerging trends in multiple substance use. Polysubstance use is prevalent but there is a paucity of research exploring effective treatments and interventions.

A latent class analysis of patterns of tobacco and cannabis use in Australia and their health-related correlates

INTRODUCTION

The shifting landscape in Australia's tobacco and cannabis policies and emerging new products and modes of administration may increase experimentation and the risks of addiction to these drugs.

METHODS

We analysed cross-sectional data from the 2019 National Drug Strategy and Household Survey (n = 22,015) of Australians aged 14 and above. Latent class analysis was used to identify distinct groups based on types of tobacco and cannabis products used. The socio-demographic, health-rated correlates and past-year substance use of each latent class was examined.

RESULTS

A four-class solution was identified: co-use of tobacco and cannabis (2.4%), cannabis-only (5.5%), tobacco-only (8.0%) and non-user (84.0%). Males (odds ratio [OR] range 1.5-2.9), younger age (OR range 2.4-8.4), moderate to high psychological distress (OR range 1.3-3.0), using illicit substances in the last year (OR range 1.41-22.87) and high risk of alcohol use disorder (OR range 2.0-21.7) were more likely to be in the tobacco/cannabis use classes than non-users. Within the co-use class, 78.4% mixed tobacco with cannabis and 89.4% had used alcohol with cannabis at least once.

DISCUSSION AND CONCLUSIONS

Approximately 16% of respondents used tobacco or cannabis, or both substances, and no major distinct subgroups were identified by the use of different product types. Mental health issues and the poly-substance use were more common in the class who were co-users of cannabis and tobacco. Existing policies need to minimise cannabis and tobacco-related harms to reduce the societal burden associated with both substances.

Polysubstance Use Patterns among Outpatients Undergoing Substance Use Disorder Treatment: A Latent Class Analysis

Substance Use Disorders (SUDs) pose significant challenges to both individuals and society at large. The primary focus of existing research with clinical SUD populations has been on individual substances, but research is required to better understand the profiles of individuals who use different substances simultaneously. The purpose of the current study was, therefore, to identify patterns of use among subjects (n = 1025) who reported using multiple substances by adopting a Latent Class Analysis (LCA) methodology. The Addiction Severity Index (ASI-lite) was included as a measure of substance misuse, we performed LCA to identify patterns of substance use through the administration of the ASI-Lite. Responses were collected from the following substances: alcohol, cannabis/cannabinoids, opioids and heroin, and cocaine. Results identified two latent classes: (1) alcohol use dominant, and (2) poly-abuser use dominants. Class 1 represented 60.0% of the sample and refers to individuals with the dominant use of alcohol, of those a higher proportion (47%) reported low-frequency use (1 to 7 days per month) and 26% reported a frequency of use of 24 to 30 days per month. Furthermore, 18% used alcohol in combination with cocaine. Class 2 represents 40.0% of the sample. This class is characterized by low-frequency and high-frequency users of several substances. The results obtained highlight the importance of deepening the study of the concomitant use of substances in individuals with SUDs to better understand the health risk of the combined use of two or more substances.

The Role of Cannabinoids in CNS Development: Focus on Proliferation and Cell Death

The active principles of Cannabis sativa are potential treatments for several diseases, such as pain, seizures and anorexia. With the increase in the use of cannabis for medicinal purposes, a more careful assessment of the possible impacts on embryonic development becomes necessary. Surveys indicate that approximately 3.9% of pregnant women use cannabis in a recreational and/or medicinal manner. However, although the literature has already described the presence of endocannabinoid system components since the early stages of CNS development, many of their physiological effects during this stage have not yet been established. Moreover, it is still uncertain how the endocannabinoid system can be altered in terms of cell proliferation and cell fate, neural migration, neural differentiation, synaptogenesis and particularly cell death. In relation to cell death in the CNS, knowledge about the effects of cannabinoids is scarce. Thus, the present work aims to review the role of the endocannabinoid system in different aspects of CNS development and discuss possible side effects or even opportunities for treating some conditions in the development of this tissue.

A Scoping Review of Gender, Sex and Sexuality Differences in Polysubstance Use in Adolescents and Adults

BACKGROUND

Polysubstance use is a common, problematic behavior that increases risk of harm to self and others. Research suggests that rates may vary based on gender, sex and sexuality. Understanding the current state of this literature may inform prevention and treatment of polysubstance use, leading to reduced public health burden.

OBJECTIVES

This review aimed to synthesize research on gender, sex and sexuality differences in polysubstance use in adults and adolescents.

METHODS

A scoping review was conducted using all EBSCO databases, PubMed and Google Scholar to identify articles examining the effects of gender, sex and sexuality on polysubstance use. Polysubstance use was defined broadly as the use of any combination of substances over any time period and included licit (alcohol, tobacco) and illicit substances, concurrent and simultaneous use, from lifetime to daily use and use at any frequency. Studies were considered if they were published in peer-reviewed journals between January 1990 and October 2020 and were written in English. Publicly available data sources were also utilized to fully capture prevalence data that has not been published elsewhere.

RESULTS

Findings were mostly inconsistent and often conflicting. Only two findings were generally consistent: adult men were overall more likely to report polysubstance use than adult women, and sexual and gender minorities report more frequent polysubstance use than non-minorities.

CONCLUSIONS

Research has been unable to clearly elucidate differences in polysubstance use prevalence and patterns according to gender, sex and sexuality. Several recommendations are offered to advance future research and address limitations of current research.

The latent class structure of substance use in US adults 50 years and older

OBJECTIVE

Substance use rates have increased in adults 50 years and older, and substance use in this population is associated with significant consequences. Given that little is known about their underlying substance use patterns, the objective was to identify latent classes of adults 50 years and older by past-year substance use, past-month substance use, and past-year substance use disorder (SUD) diagnosis.

METHODS

The National Survey on Drug Use and Health is an annual nationwide cross-sectional U.S. survey. Participants were 35,229 civilian, non-institutionalized U.S. residents, 50 years and older. Past-year and past-month alcohol, tobacco, marijuana, heroin, cocaine, methamphetamine use, and opioid, stimulant, and tranquilizer/sedative prescription drug misuse (PDM) were captured, as was past-year DSM-IV SUD from these substances. Correlates included mental health, physical health, and healthcare utilization variables.

RESULTS

Latent class analysis indicated four past-year or past-month substance use subgroups (Alcohol-Only, Alcohol-Tobacco-Marijuana, Cocaine-Polydrug, PDM-Polydrug), with SUD prevalence rising from 3.2% to 17.3%, 68.8%, and 78.5% by past-year subgroup; similarly, rates of past-year suicidal ideation increased from 2.1%, to 4.8%, 12.0%, and 20.4% by past-year subgroup. For SUD, there were three subgroups (Low Nicotine Dependence [ND], High Alcohol Use Disorder, Multiple SUDs). Over 90% of adults were in a low-risk subgroup (i.e., Alcohol-Only and Low ND), but members of Cocaine-Polydrug, PDM-Polydrug, or Multiple SUDs latent classes had high rates of mental and physical health concerns.

CONCLUSIONS

Most adults 50 and older have lower risk profiles, but those engaged in PDM or cocaine use are heavily substance-involved and need screening and likely multi-disciplinary intervention.