Key neurochemical markers for the prevention of suicide

The association between suicidality and treatment with selective serotonin reuptake inhibitors in older people with major depression: a systematic review

BACKGROUND

Suicide among the elderly is an emerging public health issue. In Australia, suicide is a leading cause of death, most notably amongst elderly men over the age of 75. Depression is one of the main causes of suicide in older people. Selective serotonin reuptake inhibitors are considered to be a safe pharmacological therapy in the management of depression in adults. The risk of suicidality/suicide associated with the use of antidepressants in older people is unclear.

OBJECTIVES

The objective of this review was to determine the association between treatment with selective serotonin reuptake inhibitors and suicidality/suicide in older people who suffer from major depression.

INCLUSION CRITERIA

TYPES OF PARTICIPANTS

  Consideration was given to studies that included older people aged 60 years and over, regardless of gender or ethnic background, with Diagnostic and Statistical Manual of Mental Disorders Fourth Edition or equivalent diagnostic criteria for Major Depressive Disorder without psychotic features.  Types of intervention(s)/phenomena of interest:  The review considered treatments using any selective serotonin reuptake inhibitors medication. Comparators included placebo or a different class of antidepressants including monoamine oxidase inhibitors or tricyclic antidepressants.  Types of studies:  This review considered both experimental and observational study designs including randomized controlled trials, non-randomized controlled trials, prospective and retrospective cohort studies and case control studies.  Types of outcomes:  The primary outcome measures of interest in this systematic review were worsening or emergent suicidal ideation, attempted suicide and completed suicide. For this systematic review, the term 'suicide attempt' referred to potentially self-injurious behavior with a non-fatal outcome.

SEARCH STRATEGY

A three-step search strategy was employed that aimed to locate both published and unpublished studies in the English language. An initial search in PubMed was followed by a second search using all identified keywords and index terms across multiple databases and grey literature sites. Finally, the reference list of all identified reports and articles were searched for additional studies. METHODOLOGICAL QUALITY : Critical appraisal was undertaken by two independent reviewers using the standard critical appraisal instrument from the Joanna Briggs Institute Mata-Analysis of Statistical Assessment and Review Instrument. The McMaster Quality Assessment Scale for Harms was used to analyse reporting quality on suicide related harm.

DATA COLLECTION

The primary data on the number of emergent or worsening of suicidal ideation, attempted suicide and completed suicides, in both arms of randomized controlled trials and observational studies was extracted using the standardized data extraction tool from the Joanna Briggs Institute Mata-Analysis of Statistical Assessment and Review Instrument. Baseline demographic data on each study was collected for presentation in tabular format.

DATA SYNTHESIS

The data from randomized controlled trials and observational studies was pooled separately in statistical meta-analysis using RevMan V 5.1 software (The Cochrane Collaboration). Population demographic and other study characteristics were presented in tables and as a narrative summary.

RESULTS

Following critical appraisal, eight randomized controlled trials and five observational studies (i.e. population cohort and retrospective case control studies) with data on suicide-related events were included in the systematic review. Based on the data on TRUNCATED AT 500 WORDS.

Association study of a functional catechol-O-methyltransferase (COMT) Val108/158Met polymorphism and suicide attempts in patients with alcohol dependence

Alcohol dependence is frequently associated with aggressive and suicidal behaviour. Genetic factors contribute to both behaviours. Candidate genes, related to suicide and aggression, include genes involved in serotonin, norepinephrine and dopamine pathways. The enzyme catechol-O-methyl transferase (COMT) degrades dopamine, epinephrine and norepinephrine. The functional polymorphism (COMT Val108/158Met) affects COMT activity, with the valine (Val) variant associated with higher and the methionine (Met) variant with lower COMT activity. This polymorphism is associated with aggressive and suicidal behaviour, but the literature data on this relationship is contradictory and inconsistent. The hypothesis of this study was that Met allele carriers with alcohol dependence will have a higher frequency of suicide attempts compared to other genotypes. Participants were 312 male and 81 female medication-free patients with alcohol dependence and 487 male and 122 female unrelated, non-suicidal medication-free Caucasian healthy subjects. Our results showed significant (χ2 test with standardized residuals) differences in the frequencies of COMT variants in all alcoholics, alcoholics with different comorbid diagnoses, and in male but not in female alcoholics, with or without suicide attempts. Male alcoholic suicide attempters, compared to male non-attempters, had the higher frequency of Met/Met genotype or Met allele, and significantly (Kruskal-Wallis ANOVA on ranks and Mann-Whitney test) higher aggression and depression scores. These results confirmed the associations between Met allele and aggressive behaviour or violent suicide attempts in various psychiatric diagnoses, and suggested that Met allele of the COMT Val108/158 Met might be used as an independent biomarker of suicidal behaviour across different psychopathologies.