Chronic high-dose (CHD) prescription opioid use is a major public health concern. Although CHD opioid use has been associated with psychiatric disorders, the causality could go both ways. Some studies have already linked psychiatric disorders to an increased risk of transitioning to chronic opioid use, and longitudinal data identifying psychiatric disorders as predictors of CHD opioid use could shed further light on this issue.

To prospectively examine the relationship between the presence of a psychiatric disorder and subsequent development of CHD opioid use in primary care patients newly receiving opioids.

Data were included from 137 778 primary care patients in The Netherlands. Cox regression modelling was used to examine the association between psychiatric disorders prior to a new opioid prescription and subsequent CHD opioid use (≥90 days; ≥50 mg/day oral morphine equivalents) in the subsequent 2 years.

Of all patients receiving a new opioid prescription, 2.0% developed CHD opioid use. A psychiatric disorder before the start of an opioid prescription increased the risk of CHD opioid use (adjusted hazard ratio HR = 1.74; 95% CI 1.62–1.88), specifically psychotic disorders, substance use disorders, neurocognitive disorders and multiple co-occurring psychiatric episodes. Similarly, pharmacotherapy for psychosis, substance use disorders and mood and/or anxiety disorders increased the risk of CHD opioid use. Psychiatric polypharmacy conferred the greatest risk of developing CHD opioid use.

Psychiatric disorders increase the risk of developing CHD opioid use in patients newly receiving prescription opioids. To reduce the public health burden of CHD opioid use, careful monitoring and optimal treatment of psychiatric conditions are advised when opioid therapy is initiated.

Tackling Scotland's drug-related deaths and improving outcomes from substance misuse treatments, including residential rehabilitation, is a national priority.

To analyse and report outcomes up to 4 years after attendance at a substance misuse residential rehabilitation programme (Lothians and Edinburgh Abstinence Programme).

In total, 145 participants were recruited to this longitudinal quantitative cohort study of an abstinence-based residential rehabilitation programme based on the therapeutic community model; 87 of these participants were followed up at 4 years. Outcomes are reported for seven subsections of the Addiction Severity Index-X (ASI-X), together with frequency of alcohol use, heroin use, injecting drug use and rates of abstinence from substances of misuse.

Significant improvement in most outcomes at 4 years compared with admission scores were found. Completing the programme was associated with greater rates of abstinence, reduced alcohol use and improvements in alcohol status score (Mann–Whitney U = 626, P = 0.013), work satisfaction score (U = 596, P = 0.016) and psychiatric status score (U = 562, P = 0.007) on the ASI-X, in comparison with non-completion. Abstinence rates improved from 12% at baseline to 48% at 4 years, with the rate for those completing the programme increasing from 14.5% to 60.7% (χ2(2, 87) = 9.738, P = 0.002). Remaining abstinent from substances at follow-up was associated with better outcomes in the medical (U = 540, P < 0.001), psychiatric (U = 273.5, P < 0.001) and alcohol (U = 322.5, P < 0.001) subsections of the ASI-X.

Attending this abstinence-based rehabilitation programme was associated with positive changes in psychological and social well-being and harm reduction from substance use at 4-year follow-up, with stability of change from years 1 to 4.

Individuals with intellectual and developmental disability (IDD) can have a high prevalence of pain, which can be managed with prescription opioids. However, the prevalence of substance use disorder is also high in this population, raising concern about opioid-related adverse events.

To assess the risk of opioid-related adverse events following opioid initiation among adults with versus without IDD.

We conducted a population-based, propensity score matched cohort study on all adults starting prescription opioid therapy in Ontario, Canada, between January 2013 and December 2018. The outcomes of interest were opioid toxicity, new opioid use disorder (OUD) diagnosis and dose escalation (≥90 mg morphine or equivalent) in the year after opioid initiation. We used Cox proportional hazards models to assess the association between IDD diagnosis and each outcome.

The hazards of opioid toxicity and OUD were significantly higher in those with IDD compared with those without IDD in unmatched analyses (opioid toxicity hazard ratio 3.19, 95% CI 2.81–5.18; OUD hazard ratio 2.36, 95% CI 2.10–2.65), whereas the hazard of dose escalation was significantly lower (hazard ratio 0.76, 95% CI 0.66–0.88). Findings were no longer significant in propensity score matched models for opioid toxicity and dose escalation, whereas the hazard of OUD diagnosis was attenuated substantially in those with IDD (hazard ratio 0.79, 95% CI 0.68–0.91).

IDD diagnosis is not a driver of opioid-related harm. The increased risk we observed is likely driven by various risk factors often present in this population.