Predisposing and protective factors influencing suicide ideation, attempt, and death in patients accessing substance use treatment: a systematic review and meta-analysis protocol

BACKGROUND

The lifetime risk of suicide in patients with substance use disorder is five to ten times the risk in the general population. Critically, up to 19% of patients continue to think about and attempt suicide even after accessing treatment. Therefore, suicidality represents a significant clinical concern in patients struggling with substance use that warrants careful investigation of the factors involved. While most previous research has relied on limited cross-sectional designs, a growing number of prospective studies are improving our understanding of the factors involved. However, a systematic study of these factors has not yet been conducted.

METHODS

The primary objective of this review and possible meta-analysis will be to identify key risk and protective factors for suicide ideation, attempt, and death in patients accessing substance use treatment, guided by current models of suicide. Secondary and tertiary objectives will be to obtain pooled effect sizes for the factors identified and to disaggregate factors for suicidality before and after treatment, and for suicidal thought versus action. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we will conduct an electronic search of the literature using the databases Embase, Medline, PsycINFO, and Web of Science. Two authors will independently screen studies based on pre-specified inclusion and exclusion criteria, extract relevant data, and assess study quality. Observational and randomized-controlled studies will be included, whereas case-studies and reviews will be excluded. We will extract data on risk and protective factors associated with suicide ideation, attempt (odds or risk ratios), and death (hazard ratio). Given sufficient data (> 5 studies), we will calculate pooled effects using comprehensive meta-analysis.

DISCUSSION

This systematic review will contribute to our knowledge of risk and protective factors for suicidality in patients before and after treatment. Understanding these factors will help define areas of research for further investigation to ultimately inform risk assessment and prevention strategies.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO (reference number: CRD42018076260).

A comparative pharmacokinetic and dynamic evaluation of alprazolam sustained-release, bromazepam, and lorazepam

Sustained-release (SR) alprazolam may facilitate compliance with oral benzodiazepine treatment of panic disorders that currently requires doses administered three or four times daily. To compare the pharmacokinetic, psychomotor performance, and subjective effects of alprazolam SR (1.5 mg), bromazepam (3 mg taken three times daily), and lorazepam (1 mg taken three times daily), 13 male volunteers (aged 20-45 years) randomly received on four separate occasions one of these medications or placebo. Once before and 11 times after drug administration, the subjects were tested using psychomotor performance tests (manual tracking and digit-symbol substitution test [DSST]) and computerized questionnaires (such as the Tufts University Benzodiazepine Scale [TUBS], the Addiction Research Center Inventory, and the visual analog scales) to determine the subjective effects of the drugs. Blood samples for the determination of the plasma levels of the drugs were collected before and 17 times after the drug was administered. A peak plateau of plasma alprazolam began approximately 6 hours after the dose, which was later than the initial peaks for lorazepam and bromazepam (1-2 hours after the dose). Once this plateau had begun, alprazolam SR sustained that concentration better than did the other two formulations. Of the 10 measures on which the response averaged for the first 14 hours differed among drugs (p < 0.05), bromazepam differed from placebo on two measures, lorazepam on four (including DSST Performance and TUBS Sedation), and alprazolam SR on nine (including all four affected by lorazepam). Lorazepam and alprazolam, but not bromazepam, produced significantly more sedation than placebo. The doses of the three drugs were not equipotent in sedation and mood effects. None of the drugs tested differed from placebo on measures relevant to abuse liability.

Pharmacologic effects and abuse liability of bretazenil, diazepam, and alprazolam in humans

OBJECTIVES

To assess the pharmacologic effects and abuse liability of bretazenil, a partial benzodiazepine agonist, and compare them to the short-term effects of diazepam and alprazolam over a range of doses.

METHODS

This was a placebo, within-subject, randomized, double-blind study conducted in 28 male volunteers. They were experienced but nondependent users of central nervous system depressants who had the ability to reliably distinguish 150 mg secobarbital from placebo and to report positive subjective effects. Subjects randomly received placebo and the two middle doses of diazepam, bretazenil, and alprazolam for the first 7 days of the study and, depending on their clinical response, received either the highest or the lowest dose of each drug for the remaining 3 days. Pharmacologic effects were assessed by use of objective tests (e.g., psychomotor performance), subject-rated questionnaires (e.g., Profile of Mood States), and observer-rated scales.

RESULTS

All three drugs were clearly distinguishable from placebo on most measures. Diazepam and alprazolam produced dose-related psychomotor and memory impairment, whereas bretazenil produced a flatter slope. Both alprazolam and diazepam produced dose-dependent increases in subject and observer-rated sedation and liking, whereas bretazenil showed increases compared with placebo, but these effects were not dose dependent.

CONCLUSIONS

Results from the study supported the view that bretazenil may have a partial agonist pharmacologic profile. Scores on subjective effects scales considered important for abuse liability assessment suggest a lower abuse liability of bretazenil than diazepam and alprazolam.