Examining the Utility of a General Substance Use Spectrum Using Latent Trait Modeling

Development and validation of the Substance Use Protective Strategies Scale (SUPSS) among Polish young adults using various psychoactive substances

Research supports protective behavioral strategies (PBS) as effective in reducing substance use, intoxication, and/or related risks/harms. However, despite the predominance of polysubstance use and common co-occurrence of different substance use disorders (SUDs), previous PBS research has been limited in terms of substance-specific measurement. This study sought to develop and validate a measure of PBS that is not substance-specific. Building from initial pilot work, we tested the psychometric properties of the Substance Use Protective Strategies Scale (SUPSS) in a large sample of young adults (N = 7325, aged 18-30), who reported using multiple psychoactive substances (other than alcohol and nicotine), recruited via social media in Poland. By splitting the sample, we conducted exploratory (n = 3709) and confirmatory factor analysis (n = 3614), which supported a 4-factor structure with 19 items (7 items dropped): Preparation for use (α = 0.66), Manner of use (α = 0.85), Additional concerns (α = 0.74), and Setting (α = 0.62). Configural, metric and scalar invariance were supported across sex, age, and user status for most substance types (cannabis, dissociatives, etc.). Further, the SUPSS factors were strongly associated with substance-related harms (R-squared = 0.495) and SUD symptoms (DUDIT, R-squared = 0.570). Our model fit was adequate (but not excellent), and two subscales had low internal consistency, highlighting the need for further improvement of the SUPSS. Despite its limitations, we found the SUPSS to have strong psychometric properties and it holds promise to enhance PBS research and harm reduction-oriented interventions.

Why do we focus on the exception and not the rule? Examining the prevalence of mono- versus polysubstance use in the general population

BACKGROUND AND AIMS

Substance use disorders (SUDs) are predominantly studied as drug class specific constructs (e.g. opioid versus alcohol use disorder). Polysubstance use (PSU), or the use of two or more substances from multiple drug classes, is only captured diagnostically by the co-occurrences of drug class-specific SUDs, and in many ways is relegated to a secondary position within the literature. However, this is not consistent with mounting empirical evidence regarding the high prevalence of PSU patterns compared with a mono-use pattern (i.e. all use contained within a single-drug class). The current study measured how many individuals in the general United States population could be characterized as having a mono-use versus PSU pattern.

METHODS

We measured the prevalence of mono-use versus PSU in those who used substances in the past year, those with at least two symptoms of an SUD and in those who received treatment for alcohol/drug problems in the past year using data from the National Survey on Drug Use and Health (NSDUH) from years 2015-19.

RESULTS

Of those who used substance(s) in the past year, 64% reported a mono-use pattern. Importantly, only 26% of those who had at least two symptoms of an SUD and 22% of those who received treatment for substance use reported a mono-use pattern.

CONCLUSIONS

Although mono-use of drugs is common in the United States at the public health level, it is a much less common presentation than polysubstance use (PSU) among individuals of even mild substance use disorder severity. This means that common efforts to study substances in isolation do not focus upon the most common presentation of the phenomenon. We discuss the importance and implications of embracing a PSU framework in the study of substance misuse and substance use disorders.

Can severity of substance use be measured across drug classes? Estimating differential item functioning by drug class in two general measures of substance use severity

BACKGROUND

Substance use severity is frequently measured using generic (i.e., non-drug specific) items. Yet, the measurement properties of these items must be evaluated for measurement invariance across inidividuals who use differing substances to ensure total scores can be compared across groups.

METHOD

This study used data from two independent samples (n1 = 474; n2 = 5183) and two measures of general substance use severity with generic items, the Patient Reported Outcomes Measurement Information System (PROMIS) Severity of Substance Use and DAST-10, to examine for differential item functioning (DIF) across substances (i.e., sedatives, opioids, amphetamines, cocaine, and cannabis). We utilized moderated nonlinear factor analysis to estimate DIF. Finally, we compared factor scores across estimation methods with and without accounting for DIF to examine the impact of DIF.

RESULTS

A minority of items showed statistically significant DIF in each scale (Items with DIF: PROMIS Sample 1: 5/37; PROMIS Sample 2: 7/20; DAST-10 Sample 2: 3/10). Factor scores across scoring methods showed extremely high correlations (0.994 - 0.999), estimates of mean differences across substance groups did not vary considerably across scoring methods, but measurement differences were correlated with factor scores.

DISCUSSION

These findings suggest that these two measures of substance use severity can be used across individuals using different substances. Factor scores appear similar across scoring methods and mean differences do not appear to be substantially biases. Measures with generic items may offer a parsimonious alternative to measures with drug specific items but more research is needed to evaluate the robustness of these findings.

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.

Test-retest reliability of a new assessment to detect detailed temporal patterns of polysubstance use

OBJECTIVE

While polysubstance use is highly prevalent among people who use drugs, the field lacks a reliable assessment that can detect detailed temporal patterns of polysubstance use. This study assessed the test-retest reliability of the newly developed Polysubstance Use-Temporal Patterns Section (PSU-TPS).

METHODS

Participants who used cocaine plus alcohol and/or marijuana at least once in the past 30 days (n = 48) were interviewed at baseline and approximately 7 days later (retest) using the Substance Abuse Module and the PSU-TPS. Reliability of PSU-TPS measures of quantity, frequency, and duration of polysubstance use was examined using intra-class correlation coefficients (ICCs) and kappa tests.

RESULTS

Excellent reliability was observed for frequencies of concurrent polysubstance use patterns in the past 30 days (ICC range: 0.90-0.94) and quantity of alcohol use (ICC = 0.83), and fair to good reliability was observed for duration of substance use (ICC range: 0.52-0.73).

CONCLUSION

Detailed information regarding cocaine, alcohol, and marijuana polysubstance use in the past 30 days can be reliably measured with the PSU-TPS. Data on the order and timing of polysubstance use at the hourly level will improve our understanding of the implications of sequential and simultaneous use patterns, which can help inform treatment and prevention efforts.

An exploration of multivariate symptom clusters of cannabis use disorder in young adults

AIMS

Since the release of the DSM-V, CUD has been understood as a unidimensional construct. However, continued research has identified separate symptom clusters relating to consumption, loss of control, and withdrawal within substance use disorder criteria that may pose separate risk factors and functional difficulties. The current study aims to examine how symptom clusters commonly manifest in young adults that use cannabis using a latent class analysis (LCA) and explore how these clusters are related to co-occurring psychological constructs.

METHODS

1174 (aged 18-34) participants completed a battery of assessments on substance use and other psychological constructs. LCA was conducted on 17 symptoms corresponding with DSM-V CUD criteria. Multinomial regressions were used to examine class membership and commonly co-occurring psychopathology and psychological constructs.

RESULTS

LCA results identified a 'No problems' class, a 'Moderate consumption' class characterized by moderate probability of endorsing consumption items, a 'Consumption with Moderate Loss of Control' class, characterized by endorsing consumption and loss of control items but minimal endorsement of withdrawal items, a 'Consumption with Moderate Withdrawal' class characterized by moderate probability of endorsing all item types, and 'High Consumption, Loss of Control, Withdrawal' class characterized by high probability of endorsing all items. Multinomial regressions indicated some class differences in psychological constructs.

CONCLUSIONS

Symptom clusters differed in terms of CUD criteria, especially for those in our sample with moderate/severe problems. Findings suggest intervention efforts may benefit from treatment targeted at various presentations of CUD.

Is lower severity alcohol use disorder qualitatively different than more severe manifestations? An evaluation of multivariate symptom clusters

BACKGROUND AND AIMS

Alcohol use disorder (AUD), since the release of DSM-V, is conceptualized and studied as a unidimensional construct. However, previous research has identified clusters of AUD symptoms related to excessive consumption/tolerance, loss of control/social dysfunction and withdrawal/craving that have shown differential genetic risks, personality associations and predictive ability. Although past 'variable-centered' (e.g. factor-analytic) studies have demonstrated the importance of these clusters, the current study aimed to examine how these clusters commonly manifest using a 'person-centered' approach (e.g. latent class).

DESIGN

Cross-sectional in-person assessment.

SETTING

Indiana, USA.

PARTICIPANTS

A convenience sample of 1390 young adults (mean age = 21.43, SD = 2.47) recruited for an over-representation of alcohol problems (65% with AUD).

MEASUREMENTS

Latent class analysis (LCA) was conducted on 23 criteria from the Semi-Structured Interview on the Genetics of Alcoholism (SSAGA) that align with DSM-V AUD symptoms. Identified latent classes were characterized using multinomial regressions to examine the association of class and measures of alcohol use, other externalizing psychopathology, internalizing problems and personality.

FINDINGS

LCA results identified a 'Low Problems' class (34% of sample), a 'Heavy Consumption' class (26%) characterized by high endorsement probabilities of essentially only consumption/tolerance symptoms, a 'Consumption and Loss of Control' class (31%) characterized by endorsing consumption/tolerance and loss of control/social dysfunction symptoms, and finally a 'Consumption, Loss of Control and Withdrawal' class (9%) characterized by high endorsement probabilities of all symptom clusters. Multinomial regression results indicated an increasing spectrum of severity in terms of psychological impairment.

CONCLUSIONS

AUD appears to manifest as different clusters of symptoms at different severity levels.

Applying network analysis to investigate substance use symptoms associated with drug overdose

BACKGROUND

Drug overdose deaths have been increasing over the last several decades. While single substance classes, such as opioids, have been implicated in this rise, less is known about the contributions of polysubstance use (PSU) and other combinations of specific substances and symptoms that may be a risk factor for drug overdose.

METHODS

Symptoms of alcohol, cannabis, and other drug use disorders, as well as co-substance use indicators, were assessed and then examined via network analysis in a sample of young adults (N = 1540). Features of the estimated symptom network were investigated, including topology and node centrality, as well as bridge centrality, which further examines node centrality while accounting for the nodes belonging to discrete communities.

RESULTS

Individual symptoms were more strongly associated with other symptoms within the same substance class than across substance classes. Tolerance and withdrawal symptoms were the most central items in the network. However, when accounting for symptoms belonging to discrete substance classes, drug overdose emerged as a strong bridge symptom, among others.

CONCLUSIONS

As a strong bridge symptom, drug overdose had many connections with a variety of substances and symptoms, which might suggest that risk for drug overdose may be a function of overall substance use severity. Altogether, examining alcohol and substance use symptoms using a network analytic framework provided novel insights into the role PSU might play in conferring risk for drug overdose.

ILC-OPI: impulsive lifestyle counselling versus cognitive behavioral therapy to improve retention of patients with opioid use disorders and externalizing behavior: study protocol for a multicenter, randomized, controlled, superiority trial

BACKGROUND

Substance use disorders show a high comorbidity with externalizing behavior difficulties, creating treatment challenges, including difficulties with compliance, a high risk of conflict, and a high rate of offending post-treatment. Compared with people with other substance use disorders those with opioid use disorders have the highest risk of criminal activity, but studies on the evidence base for psychosocial treatment in opioid agonist treatment (OAT) are scarce. The Impulsive Lifestyle Counselling (ILC) program may be associated with better retention and outcomes among difficult-to-treat patients with this comorbidity.

METHODS

The study is a multicenter, randomized, controlled, superiority clinical trial. Participants will be a total of 137 hard-to-treat individuals enrolled in opioid agonist treatment (OAT). Participants will be randomized to either a standard treatment (14 sessions of individual manual-based cognitive behavioral therapy and motivational interviewing (MOVE-I)) or six sessions of ILC followed by nine sessions of MOVE-I. All participants will receive personalized text reminders prior to each session and vouchers for attendance, as well as medication as needed. The primary outcome is retention in treatment. Secondary measures include severity of drug use and days of criminal offending for profit three and nine months post-randomization. A secondary aim is, through a case-control study, to investigate whether participants in the trial differ from patients receiving treatment as usual in municipalities where ILC and MOVE-I have not been implemented in OAT. This will be done by comparing number of offences leading to conviction 12 months post-randomization recorded in the national criminal justice register and number of emergency room contacts 12 months post-randomization recorded in the national hospital register.

DISCUSSION

This is the first randomized, controlled clinical trial in OAT to test the effectiveness of ILC against a standardized comparison with structural elements to increase the likelihood of exposure to the elements of treatment. Results obtained from this study may have important clinical, social, and economic implications for publicly funded treatment of opioid use disorder.

TRIAL REGISTRATION

ISRCTN, ISRCTN19554367 , registered on 04/09/2020.

Symptoms of anxiety, depression, and borderline personality in alcohol use disorder with and without comorbid substance use disorder

OBJECTIVE

Alcohol use disorder (AUD) is highly comorbid with other substance use disorders (SUDs) as well as other psychiatric disorders, such as anxiety, depression, and Borderline Personality Disorder (BPD). However, studies of persons with AUD rarely account for its comorbidity with other SUDs. Some research suggests that BPD symptoms reflect an important connection between internalizing disorders and SUDs. The current study investigated: 1) the levels of trait anxiety and symptoms of depression and BPD in persons with an AUD as a function of comorbid SUDs (cannabis use disorder - CUD) and other substance use disorder (oSUD), and 2) the influence of BPD on the association between severity of overall lifetime SUD symptoms (AUD + CUD + oSUD) and both trait anxiety and symptoms of depression.

METHOD

Trait anxiety and symptoms of depression and BPD were assessed in 671 young adults (351 men; 320 women; mean age 21 years) separated into four groups: Controls (n = 185), AUD-only (134), AUD + CUD (n = 210), and AUD + oSUD (n = 142).

RESULTS

Trait anxiety and symptoms of depression and BPD were elevated in all AUD groups compared with controls, and in the AUD + oSUD group compared with all other groups as well. Structural models also indicated that BPD symptoms accounted for all of the variance in lifetime SUD symptoms associated with Trait Anxiety, and a significant portion of the variance in lifetime SUD symptoms associated with depression symptoms.

CONCLUSION

Results indicate that when AUD is comorbid with oSUD, it is associated with more severe AUD symptoms and higher levels of trait anxiety and symptoms of both depression and BPD. The results also indicate that BPD symptoms account for the majority of the variance in SUD symptoms associated with both trait anxiety and depression, suggesting that a considerable amount of the internalizing symptomatology in AUD/SUDs is associated with BPD psychopathology.