Could epigenetics play a role in suicidal behavior in older age?

Psychiatry and sensation: the epigenetic links

A complex interaction among sensory, social and epigenetic determinants in psychiatric conditions was described across all age strata. The high prevalence of mental disorders in individuals with sensory deficits might be attributed to the interaction among social isolation, cognitive functioning and sensory processing. The epigenetic implications of such interactions were examined: environmental and social factors can affect gene expression and impact the pathogenesis of psychiatric disorders also through sensory processing. This article discussed the role of social determinants, in other words, social isolation, loneliness and chronic stress, in promoting psychiatric disorders and, in a vicious circle, sensory deficits (vision, hearing, olfaction and somatosensation). We emphasized the importance of integrating social, sensory and epigenetic factors to target different treatments for psychiatric conditions.

Apolipoprotein E genotype, inflammatory biomarkers, and non-psychiatric multimorbidity contribute to the suicidal ideation phenotype in older age. The Salus in Apulia Study

BACKGROUND

Possible relationships between suicidal ideation and biopsychosocial predictors in older age are unclear. In the population-based Salus in Apulia Study, we investigated the relationships among biomarkers, socio-demographic, psychopathological, inflammatory and metabolic characteristics and suicidal ideation in 1252 older subjects.

METHODS

Suicidal ideation was evaluated with the brief version of the Columbia-Suicide Severity Rating Scale. Apolipoprotein E (APOE) genotype and inflammatory profile [interleukin (IL)-6, tumor necrosis factor (TNF)-α, C-reactive protein (CRP)] were evaluated. A machine learning algorithm, the Random Forest (RF), selected potential biopsychosocial factors associated to suicidal ideation.

RESULTS

Suicidal ideators accounted for 2.32 % of subjects, were female, smokers, and obese with multimorbidity. After adjusting for age, gender, education and social dysfunction, logistic regression analyses revealed that suicidal ideation was associated to late-life depression (LLD) (odds ratio:21.71,95 % confidence interval:9.22-51.14). In the full RF model, asthma was the most important contributor to suicidal ideation. In the final RF model, education, age, and mild cognitive impairment followed by gender and global cognition were considered the most important contributors. Among biomarkers, in the final RF model, IL-6 followed by TNF-α, APOE ε4 allele presence, CRP and high-density lipoprotein cholesterol contributed most to suicidal ideation.

LIMITATIONS

A relatively small number of older subjects with suicidal ideation (2.3 %); we did not distinguish between active and passive suicidal ideation.

CONCLUSIONS

Although LLD is a strong determinant of suicidal ideation, other non-psychiatric factors, i.e., serum inflammation biomarkers, APOE ε4 allele, and multimorbidity, should be taken into account when evaluating a suicidal ideation phenotype in older age.