Pharmacist-prescriber collaborative models of care for opioid use disorder: an overview of recent research.

PURPOSE OF REVIEW: Collaborative models of care where pharmacists work alongside physicians have been developed for a range of physical health conditions, with benefits including improved patient outcomes and increased access to ongoing care. Opioid agonist treatment (methadone and buprenorphine) is a clinically effective and cost-effective treatment for opioid use disorder that is under-utilized in many countries due to a shortage of prescribers. In recent years, there has been increased interest in the development of collaborative models that utilize pharmacists to overcome barriers to treatment. In this article, we present a narrative review to synthesise recent work in this rapidly developing area. RECENT FINDINGS: Two key aspects of opioid agonist treatment were identified: Collaborative models have utilized pharmacists to facilitate buprenorphine induction, and collaborative models provide increased capacity for delivering ongoing care in a variety of settings and patient groups where prescriber access is limited. Pharmacists have undertaken direct patient care responsibilities with varying degrees of autonomy, with benefits including a reduction in prescriber workload, and improvements in treatment retention and continuity of care. SUMMARY: Collaborative models in which pharmacists are responsible for buprenorphine induction and ongoing management with methadone and buprenorphine have been shown to reduce demands on prescribers while improving or maintaining patient outcomes, and appear feasible and acceptable in a wide range of outpatient settings.

Risky alcohol consumption among women in Australia attending breast screening services: an exploratory cross-sectional study.

BACKGROUND AND AIMS: Alcohol is a major modifiable risk factor for female breast cancer, with breast cancer risk now associated with substantially lower consumption levels than those previously deemed safe. This study sought to measure risky drinking among women attending breast screening services in Australia according to new national alcohol guidelines and to compare daily, weekly and recent (past 12 months) consumption to Australian gender and age population norms. DESIGN, SETTING AND PARTICIPANTS: This study was a retrospective analysis of cross-sectional data from the Lifepool Project (collected October 2011-January 2016) in Victoria, Australia, comprising a convenience sample of women attending breast screening services aged 40+ years. MEASUREMENTS: Typical and heavy alcohol consumption patterns over the previous 12 months (frequency, quantity), socio-demographic (e.g. age, education) and health-related (e.g. menopause status, breast cancer history) characteristics. Primary outcomes were the proportion of women drinking at a level exceeding new guidelines for weekly and daily alcohol consumption. FINDINGS: Of 49 240 women, mean age was 59.94 years (standard deviation = 7.14, range = 40-94 years). Most women had consumed alcohol during the past 12 months [41 628, 85.48%, 95% confidence interval (CI) = 85.16, 85.79]. One in five women (8464, 18.34%, 95% CI = 17.99, 18.69) were drinking at a level exceeding new national guidelines for weekly consumption (i.e. greater than 10 standard drinks per week), and one in six (7446, 15.60%, 95% CI = 15.28, 15.93) were exceeding new guidelines for consumption on a single day (i.e. greater than four standard drinks on any 1 day, more than once per month). The proportion of women in this sample drinking daily (4.21-11.19%), weekly (34.73-50.71%) and in the past 12 months (74.96-90.81%) was significantly greater among nearly all age groups (by decade), compared with Australian gender and age norms [drinking daily (3.4-9.1%), weekly (27.1-37.6%) and in the past 12 months (64.4-81.9%)]. CONCLUSIONS: There appears to be a high prevalence of risky alcohol consumption among a large convenience sample of breast screening service clients in Australia using new national alcohol guidelines introduced in December 2020.

A Latent Class Analysis of Perceived Barriers to Help-seeking Among People with Alcohol Use Problems Presenting for Telephone-delivered Treatment.

AIMS: Despite the magnitude of alcohol use problems globally, treatment uptake remains low. This study sought to determine the proportion of people presenting to telephone-delivered alcohol treatment who are first-time help-seekers, and explored perceived barriers to help-seeking to understand the barriers this format of treatment may help to address. METHODS: Secondary analysis of baseline data from a randomized controlled trial of a telephone-delivered intervention for alcohol use problems. Latent class analysis (LCA) identified participant profiles according to self-reported barriers to alcohol treatment. RESULTS: Participants' (344) mean age was 39.86 years (SD = 11.36, 18-73 years); 51.45% were male. Despite high alcohol problem severity (Alcohol Use Disorder Identification Test: mean = 21.54, SD = 6.30; 63.37% probable dependence), multiple barriers to accessing treatment were endorsed (mean = 5.64, SD = 2.41), and fewer than one-third (29.36%) had previously accessed treatment. LCA revealed a two-class model: a 'low problem recognition' class (43.32%) endorsed readiness-for-change and attitudinal barriers; a 'complex barriers' class (56.68%) endorsed stigma, structural, attitudinal and readiness-to-change barriers, with complex barrier class membership predicted by female sex (adjusted OR = 0.45, 95% CI 0.28, 0.72) and higher psychological distress (adjusted OR = 1.13, 95% CI 1.08, 1.18). CONCLUSION: The majority of people accessing this telephone-delivered intervention were new to treatment, yet had high alcohol problem severity. Two distinct profiles emerged, for which telephone interventions may overcome barriers to care and tailored approaches should be explored (e.g. increasing problem awareness, reducing psychological distress). Public health strategies to address stigma, and raise awareness about the low levels of drinking that constitute problem alcohol use, are needed to increase help-seeking.

Informing a collaborative-care model for delivering medication assisted treatment for opioid dependence (MATOD): An analysis of pharmacist, prescriber and patient perceptions.

BACKGROUND: Demand for medication assisted treatment for opioid dependence (MATOD) in Australia exceeds capacity, particularly in rural and regional areas. There is increasing recognition that community pharmacists are well-positioned to take on expanded roles in MATOD delivery, however there has been limited Australian research exploring attitudes of pharmacists, prescribers, and patients to collaborative models of care. OBJECTIVE(S): This study aimed to better understand enablers and barriers to a collaborative model for MATOD, to inform implementation in regions where increases in treatment capacity are urgently needed. METHODS: Semi-structured telephone interviews were conducted with pharmacists (n = 11), prescribers (n = 6), and patients (n = 8) recruited from the Frankston-Mornington Peninsula region in Victoria, Australia, where transport and access to services have impacts on health care utilisation. The COM-B model was used to explore perceptions of pharmacists' capability, opportunity, and motivations for delivering collaborative care. RESULTS: There was strong motivation among healthcare professionals to participate in a collaborative model of care, with the main perceived benefits including improvements in accessibility, convenience, and continuity of care, and leverage of pharmacists' high level of patient engagement. Key barriers identified by both pharmacists and prescribers included a perceived lack of pharmacist skills in some areas (capability) and resources (opportunity) to deliver collaborative care in a community pharmacy setting. Established relationships between all stakeholders (social opportunity) and communication between pharmacists and prescribers were identified as facilitators. Barriers and facilitators aligned with seven key areas: skills, confidence, relationships, patient selection, protocols, communication and resources. CONCLUSIONS: Findings informed the development of a collaborative model that was individualised, protocol based, and supported by training and clear processes. PROJECT IMPACT: This study identifies specific barriers and facilitators to a pharmacist-prescriber collaborative model of care for MATOD. The resulting model will be tested in a hybrid implementation-effectiveness trial in the Frankston-Mornington Peninsula region.

The Impact of Stigma on People with Opioid Use Disorder, Opioid Treatment, and Policy.

Illicit drug use disorders are the most stigmatised health conditions worldwide, and stigma acts as a meaningful barrier to treatment entry and treatment provision. In the context of dramatically rising opioid-related harms, it is critical that we understand the drivers of stigma and how it affects opioid use disorder treatment and policy. The aim of this narrative review is to discuss how opioid-related stigma impacts treatment provision and harm reduction, and provide potential strategies to reduce stigma at a social and structural level. We used the Framework for Integrating Normative Influences on Stigma (FINIS) to identify sources of opioid-related stigma at the macro (structural stigma), meso (public stigma) and micro (internalised stigma) levels. Reducing stigma requires strategies that target multiple levels, however addressing inequity in the laws, regulations, and rules that segregate people with opioid and other substance use disorders from mainstream society is essential.

A prospective, multisite implementation-efficacy trial of a collaborative prescriber-pharmacist model of care for Medication Assisted Treatment for Opioid Dependence: Protocol for the EPIC-MATOD study.

BACKGROUND: Medication Assisted Treatment for Opioid Dependence (MATOD) is clinically effective and cost effective, yet a lack of MATOD prescribers in the community limits access to this treatment in Australia. These shortages are often greatest in regional and rural areas. OBJECTIVE(S): The Enhancing Pharmacist Involvement in Care (EPIC)-MATOD study will evaluate clinical and implementation outcomes among people with opioid dependence receiving MATOD through a collaborative pharmacist-prescriber model of care across multiple sites in a regional location (encompassing a mix of metropolitan and non-metropolitan areas) of Victoria, Australia. METHODS AND ANALYSIS: The EPIC-MATOD study is a prospective, multisite, implementation trial of collaborative MATOD care. Pharmacists and prescribers will be recruited through the local network of opioid pharmacotherapy providers. Patients will be recruited through participating healthcare providers. After induction into the collaborative care model, patients and healthcare professionals will be followed up over 6- (patients) and 12-months (pharmacists and prescribers) in a hybrid implementation-efficacy study, with outcomes mapped to the RE-AIM framework. The primary clinical efficacy endpoint is patient retention in treatment at 26 weeks. The primary implementation outcome is treatment capacity, based on prescriber time required to provide treatment through collaborative care compared with traditional care. Secondary clinical endpoints include attendance for dosing and clinical reviews, substance use, mental and physical health and overall well-being. Implementation costs, acceptability, and provider engagement in collaborative care will be used as secondary implementation outcome indicators. Time and costs associated with collaborative care, and health service utilisation, will also be estimated. PROJECT IMPACT: The study will provide important information on outcomes and acceptability of collaborative care for MATOD, as well as the cost and key considerations in delivering a collaborative model of care in Australia and other countries where similar treatment barriers exist.

Startle-elicited Event-Related Potentials to Affective Stimuli are Associated with Recent Illicit Opioid use among Patients Receiving Opioid Agonist Treatment.

Opioid use disorder (OUD) has been linked to exaggerated attentional, affective, and arousal responses to opioid-related stimuli, as well as altered responses to other affective (eg, naturally rewarding or aversive) stimuli, particularly blunted responses to pleasant/rewarding stimuli. Both exaggerated responses to drug-related stimuli and reduced response to pleasant stimuli may influence the course of OUD and its treatment, however interpretation of studies thus far is limited by methodological issues. In the present study, we examined subjective ratings, and attenuation of the P3 component of the acoustic startle-evoked event-related potential (as a measure of attention), while viewing neutral, pleasant, unpleasant, and drug-related images. Participants prescribed opioid agonist treatment (OAT) for OUD (n = 82) were compared to a carefully-matched control group (n = 33) and to recently-abstinent participants with OUD (n = 22). Relative to controls, participants prescribed OAT gave higher positive valence ratings of drug images, and blunted valence responses to other affective images, but groups did not differ in terms of arousal ratings or P3 amplitude. Within the OAT group, linear modeling of associations between frequency of recent illicit opioid use and startle P3 amplitude found an association between increased recent illicit opioid use and reduced attention to pleasant, relative to unpleasant, images. The latter finding may have implications for interventions targeting cognitive biases in people with substance use disorder. In particular, they suggest that enhancing attention to pleasant stimuli may be as, if not more important, than the typical approach of trying to reduce attentional bias to drug-related stimuli.

An Examination of Clinician Responses to Problem Gambling in Community Mental Health Services.

Gambling problems commonly co-occur with other mental health problems. However, screening for problem gambling (PG) rarely takes place within mental health treatment settings. The aim of the current study was to examine the way in which mental health clinicians respond to PG issues. Participants (n = 281) were recruited from a range of mental health services in Victoria, Australia. The majority of clinicians reported that at least some of their caseload was affected by gambling problems. Clinicians displayed moderate levels of knowledge about the reciprocal impact of gambling problems and mental health but had limited knowledge of screening tools to detect PG. Whilst 77% reported that they screened for PG, only 16% did so "often" or "always" and few expressed confidence in their ability to treat PG. However, only 12.5% reported receiving previous training in PG, and those that had, reported higher levels of knowledge about gambling in the context of mental illness, more positive attitudes about responding to gambling issues, and more confidence in detecting/screening for PG. In conclusion, the findings highlight the need to upskill mental health clinicians so they can better identify and manage PG and point towards opportunities for enhanced integrated working with gambling services.

Outcomes of reducing stigma towards alcohol misuse during adolescence: results of a randomized controlled trial of the MAKINGtheLINK intervention.

BACKGROUND: While it is well-recognized that the stigma associated with alcohol use problems can prevent or delay help-seeking, there is limited research examining stigmatising attitudes towards alcohol misuse, or their consequences, during adolescence. The current study examined the results of a school-based intervention on adolescents' stigmatising attitudes towards alcohol misuse among their peers, and how changes in attitudes influenced intentions to encourage help-seeking, as well as participants' personal use and misuse of alcohol. METHODS: Participants (n = 463) were a subset of a larger sample participating in a randomized controlled trial of the MAKINGtheLINK intervention. Of the included participants, 287 (62%) were allocated to the intervention group and 176 (38%) to the control group. Assessments were conducted at baseline and 6-weeks, 6-months, and 12-months post-baseline. At each assessment, participants were presented with a vignette describing a peer experiencing alcohol misuse and completed the General Help Seeking Questionnaire as well as a 10-item scale measuring stigmatising attitudes. Alcohol use was also assessed. RESULTS: The intervention was associated with a greater reduction in 'weak-not-sick' attitudes over time, which in turn predicted stronger intentions to encourage help-seeking from family members and formal help sources at the 12-month follow-up. Perceptions of dangerousness did not change significantly as a result of the intervention, however overall perceptions of dangerousness demonstrated a trend towards encouraging help-seeking from formal sources. Changes in stigma were not associated with past-year alcohol use or problems. CONCLUSIONS: School-based interventions such as MAKINGtheLINK can decrease some stigmatising attitudes towards alcohol misuse during adolescence, and increase adolescents' intentions to encourage help-seeking from both formal and informal help sources. However, results varied depending on both the dimension of stigma examined and the type of help source, highlighting a complex relationship between stigma, intentions, and sources of help that requires further investigation. Importantly, reducing stigma did not appear to result in negative effects due to greater acceptance of drinking (e.g., heavier alcohol use), supporting continued efforts to reduce alcohol-related stigma during adolescence.Trial registration: Registered with the Australia and New Zealand Clinical Trials Register (ANZCTR) on the 27th of February 2013 (ACTRN12613000235707).

Twelve-month outcomes of MAKINGtheLINK: A cluster randomized controlled trial of a school-based program to facilitate help-seeking for substance use and mental health problems.

BACKGROUND: Young people experiencing mental health problems are often reluctant to seek help, particularly from professionals (i.e., doctors or mental health workers). MAKINGtheLINK is a school-based intervention that aims to help adolescents overcome barriers to seeking professional help for mental health and substance use problems. METHODS: A cluster randomised controlled trial was conducted to evaluate the 12-month outcomes of MAKINGtheLINK among 2447 participants (Mean age=14.9 years, SD=0.5 years, 50% male). Randomisation resulted in 1130 students from 11 schools allocated to receive the intervention, and 1317 students from 10 schools allocated to the wait-list control group. After the baseline assessment, follow-ups were conducted at 6-weeks (n = 2045), 6-months (n = 1874), and 12-months (n = 1827). The primary outcome measure was help-seeking behaviour, from both formal (e.g., health professionals) and informal (e.g., friends, family members) sources. The trial was registered with the Australia and New Zealand Clinical Trials Register (ANZCTR) on the 27th of February 2013 (registration number ACTRN12613000235707). FINDINGS: The intervention was not associated with overall help-seeking at the 12-month follow-up (p = 0.99, odds ratio [OR]=1.00, 95% CI for OR = 0.70-1.42), or help-seeking for depression (p = 0.28, OR = 1.21, 95%CI =0.86-1.69), stress and anxiety (p = 0.73, OR = 1.04, 95%CI = 0.74-1.47), or alcohol/other drugs (p = 0.84, OR=1.12, CI=0.37-3.37). However, the intervention was associated with increased help-seeking from formal sources (compared to informal sources) both overall (p = 0.005, OR = 1.81, 95%CI = 1.19-2.75), as well as for depression (p = 0.01, OR=2.09, 95%CI=1.19-3.67), and stress and anxiety (p < 0.006, OR = 1.72, 95%CI = 1.17-2.54). INTERPRETATION: Rates of help-seeking remained unchanged following the intervention. However, MAKINGtheLINK effectively improved the quality of adolescent help-seeking behaviour by increasing help-seeking from formal sources. As prompt treatment is essential in reducing the long-term impact of early onset mental health problems, MAKINGtheLINK has the potential to make a significant contribution to existing early intervention and prevention efforts. FUNDING: National Health and Medical Research Council (APP1047492).

Early adolescent drinking and cannabis use predicts later sleep-quality problems.

A range of biopsychosocial changes occur during adolescence that contribute to changes in the sleep-wake system. Use of alcohol and cannabis also increases during early adolescence; however, limited studies have examined the associations between changes in the use of alcohol and cannabis and later sleep problems. Participants (n = 245) aged 12 years were recruited from schools and completed a baseline assessment, which included questions about their alcohol and cannabis use. Three subsequent follow-up assessments took place approximately 2.5 years (age 14 years), 4 years (age 16 years), and 6 years (age 18 years) after baseline, with sleep quality assessed at age 18 years. Earlier drug use was associated with poorer sleep quality at age 18 years, with different facets of alcohol and cannabis important in these associations. For alcohol, heavy episodic drinking across time was associated with poorer sleep; lifetime use at age 18 years (but not prior) was also associated with poorer sleep. For cannabis, recent use at age 18 years was associated with poor sleep quality. Our findings suggest that there are associations between specific facets of alcohol and cannabis use that are related to poor sleep in adolescents. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Dynamic associations between opioid use and anhedonia: A longitudinal study in opioid dependence.

BACKGROUND: Anhedonia is a commonly reported symptom among substance-dependent populations that appears to diminish with sustained abstinence. However, previous research has not determined whether anhedonia is dynamically linked to changing patterns of drug use, nor whether it predicts subsequent drug use. AIMS: We aimed to test whether changes in illicit opioid use would predict changes in anhedonia, and whether increases in anhedonia would predict further opioid use. METHODS: We conducted a longitudinal, observational study, with a convenience sample of 121 participants with current or past-year Diagnostic and Statistical Manual for Mental Disorders, Fourth Edition Text Revision (DSM-IV-TR) opioid dependence recruited from substance use treatment and related services and from pharmacies administering opioid substitution pharmacotherapy. Anhedonia was assessed with the Temporal Experience of Pleasure Scale and frequency of illicit opioid use was assessed using timeline follow-back interviews. RESULTS: There was a significant within-subject effect (ß=-0.015; 95% CI -0.02 to -0.01; p=0.001), indicating that participants' Temporal Experience of Pleasure Scale scores typically declined (i.e. anhedonia increased) following a month with above-average opioid use and Temporal Experience of Pleasure Scale scores rose (i.e. anhedonia reduced) following a month with below-average opioid use. However, Temporal Experience of Pleasure Scale scores did not significantly predict opioid use in the subsequent month (ß=-0.04, 95% CI -0.20 to 0.12; p=0.651). CONCLUSIONS: Changes in illicit opioid use predict self-reported anhedonia, suggesting a possible causal relationship whereby anhedonia is likely to worsen with frequent drug use and diminish with prolonged abstinence. However, anhedonia does not appear to drive further drug use.

Amygdala volume mediates the relationship between externalizing symptoms and daily smoking in adolescence: A prospective study.

The current study examined amygdala and orbitofrontal cortex (OFC) volumes as mediators of the relationship between externalizing symptoms and daily smoking in adolescence. Externalizing behaviors are among the most robust predictors of adolescent smoking, and there is emerging evidence that volume reductions in the amygdala and OFC are associated with risk for substance misuse as well as aggressive, impulsive, and disinhibited tendencies. Using a prospective longitudinal design, we recruited 109 adolescents who provided data on brain volume and externalizing behaviors at age 12, and on smoking at age 18. Daily smoking at age 18 (n = 27) was predicted by externalizing behaviors (measured by the self-report Child Behavior Checklist, CBCL) as well as smaller right amygdala volumes. Right amygdala volumes mediated the relationship between externalizing symptoms and later smoking. These findings provide important insight into the neurobiological risk factors associated with adolescent smoking, and, more generally, into factors that may be associated with vulnerability to substance use disorders and related psychopathology.

Perceived Barriers and Enablers of Help-Seeking for Substance Use Problems During Adolescence.

AIM: Receiving professional help early can reduce long-term harms associated with substance use. However, little is known about the factors that influence help-seeking for substance use problems during early-mid adolescence, prior to the emergence of disorder. Given that beliefs regarding help-seeking are likely to develop early, understanding adolescent views of help-seeking during this period is likely to provide important information for prevention and intervention efforts. The current study identifies perceptions that would facilitate or prevent adolescents from seeking support for substance use problems from formal and informal help sources. METHOD: Thirty-four 12- to 16-year-olds from two schools in Melbourne, Victoria, Australia, were recruited. A qualitative interpretative design was used, incorporating semistructured, audio-recorded interviews. RESULTS: Three overlapping themes that reflected barriers or enablers to help-seeking were identified: approachability, confidentiality and trustworthiness, and expertise. Help-seeking was facilitated when adolescents believed that the help source would be supportive and understanding, would keep information confidential, and had expertise in the alcohol and drug field. Conversely, adolescents were reluctant to seek help from sources they believed would be judgmental, lacked expertise, or would inform their parents. CONCLUSIONS: These findings highlight perceptions that may influence help-seeking for alcohol and drug problems during adolescence. Further research is needed to determine if help-seeking can be facilitated by improving parents' and peers' knowledge and promoting health professionals' expertise in working with young people's alcohol and drug issues.

MAKINGtheLINK: A school-based intervention to improve help-seeking for substance use problems.

BACKGROUND: Many young people are reluctant to seek professional help for alcohol and other substance use problems, preferring to rely on family and friends. MAKINGtheLINK is a school-based intervention that teaches adolescents how to help their peers overcome barriers to engaging with professional help. The current study examined the effect of the MAKINGtheLINK programme in a sample of 12- to 15-year-old students. METHODS: Participants included 247 Grade 8 students (49% male, 51% female) recruited from 3 schools in Victoria, Australia. Participants completed questionnaires measuring barriers to professional help-seeking, help-seeking intentions and confidence to seek help at 3 time points (pre-intervention, post-intervention and 6-week follow-up). A non-controlled repeated measures design was used to assess the effect of the programme on help-seeking across time points. RESULTS: The programme decreased barriers, increased intentions to seek help from formal sources, decreased intentions to seek help from family and increased confidence to seek help for a peer. The decrease in barriers was maintained at the 6-week follow-up, as were decreased intentions to seek help from family members, and increased intentions to seek help from school counsellors and alcohol and drug workers. The effects of the intervention did not differ substantially between males and females. CONCLUSIONS: The MAKINGtheLINK is the first intervention to focus on overcoming barriers to help-seeking for substance use problems by helping adolescents develop skills to support their peers. The intervention has promise as a means of facilitating help-seeking during adolescence, although further research is needed to test its effectiveness in a more rigorous design.

Evidence that anhedonia is a symptom of opioid dependence associated with recent use.

BACKGROUND: Anhedonia is prevalent among substance-dependent populations. The hedonic allostasis model suggests this is due to the effects of addictive substances on neural substrates of reward processing. However, previous research may have been confounded by other factors likely to influence anhedonia, including tobacco use, psychopathology, and history of trauma and other stressors. Thus it remains unclear whether elevated anhedonia in substance-dependent populations is caused by substance use itself, or is due to other correlates of substance dependence. METHODS: Multivariate analysis of covariance was conducted to test whether opioid-dependent participants' anhedonia scores were elevated, relative to a non-dependent control group, after controlling for psychosocial factors likely to influence anhedonia. Correlational analyses within opioid-dependent participants were also conducted to examine whether anhedonia was associated with recent illicit opioid use or duration of abstinence. RESULTS: There was a modest, but significant, elevation in anhedonia in opioid-dependent participants, relative to controls (Partial η2=0.034, p=0.041) after controlling for psychosocial variables that were associated with anhedonia. Depressive symptoms and history of post-traumatic stress disorder also remained significantly associated with anhedonia in the adjusted model. Among participants on opioid pharmacotherapy, there were significant associations between frequency of recent illicit opioid use and scores on anhedonia measures (all rs>0.25, p<0.013), but among abstinent opioid-dependent participants, relationships between duration of abstinence and anhedonia were not significant (all rs<0.24, p>0.22). CONCLUSION: These findings support the hypothesis that use of opioids can cause anhedonia, although other psychosocial factors may also contribute to the high prevalence of anhedonia among opioid-dependent populations.

Orbitofrontal Cortex Volume and Effortful Control as Prospective Risk Factors for Substance Use Disorder in Adolescence.

BACKGROUND: Orbitofrontal cortex (OFC) dysfunction has been proposed to increase the risk for developing a substance use disorder (SUD) during adolescence. In this study, we suggest that a reduction in OFC volumes might underlie temperament-based risk factors for SUD, and examined whether smaller OFC volumes during early adolescence could predict later development of SUD. METHODS AND MATERIALS: Adolescents (n = 107; 58 male, 49 female) underwent structural MRI and completed a self-report measure of temperamental effortful control at age 12. At 3 subsequent assessments (aged 15, 16, and 18) SUD was assessed via a semi-structured clinical interview. By the third assessment, 24 participants (22.4%) had received a lifetime diagnosis of SUD. RESULTS: Smaller volumes of the left OFC, right OFC, and left medial subregions predicted lifetime history of SUD by age 18. Volumes of the left OFC and left lateral subregions were positively correlated with effortful control, and left OFC volumes mediated the relationship between effortful control and SUD. CONCLUSIONS: Smaller volumes of the OFC and low effortful control during adolescence appear to be associated phenotypes that increase the risk of subsequent SUD. Further studies examining the temporal sequence of these risk factors are needed to fully understand this relationship.