Evolution of sex-specific pace-of-life syndromes: genetic architecture and physiological mechanisms

Sex differences in life history, physiology, and behavior are nearly ubiquitous across taxa, owing to sex-specific selection that arises from different reproductive strategies of the sexes. The pace-of-life syndrome (POLS) hypothesis predicts that most variation in such traits among individuals, populations, and species falls along a slow-fast pace-of-life continuum. As a result of their different reproductive roles and environment, the sexes also commonly differ in pace-of-life, with important consequences for the evolution of POLS. Here, we outline mechanisms for how males and females can evolve differences in POLS traits and in how such traits can covary differently despite constraints resulting from a shared genome. We review the current knowledge of the genetic basis of POLS traits and suggest candidate genes and pathways for future studies. Pleiotropic effects may govern many of the genetic correlations, but little is still known about the mechanisms involved in trade-offs between current and future reproduction and their integration with behavioral variation. We highlight the importance of metabolic and hormonal pathways in mediating sex differences in POLS traits; however, there is still a shortage of studies that test for sex specificity in molecular effects and their evolutionary causes. Considering whether and how sexual dimorphism evolves in POLS traits provides a more holistic framework to understand how behavioral variation is integrated with life histories and physiology, and we call for studies that focus on examining the sex-specific genetic architecture of this integration

Optimal management of ADHD in older adults

Terje Torgersen,1,2 Bjorn Gjervan,2,3 Michael B Lensing,4 Kirsten Rasmussen5,6 1Department of Østmarka, St Olav’s Hospital, 2Department of Neuroscience, Norwegian University of Science and Technology, Trondheim, 3Department of Psychiatry, Helse Nord-Trondelag Hospital Trust, Kirkegata, Levanger, 4NevSom, Norwegian Center of Expertise for Neurodevelopmental Disorders and Hypersomnias, Women and Children’s Division, Oslo University Hospital, Oslo, 5St Olav’s Hospital, Broset Center for Research and Education in Forensic Psychiatry, Trondheim, 6Department of Psychology, Norwegian University of Science and Technology, Trondheim, Norway Background: The manifestation of attention-deficit/hyperactivity disorder (ADHD) among older adults has become an interesting topic of interest due to an increasing number of adults aged 50 years and older (≥50 years) seeking assessment for ADHD. Unfortunately, there is a lack of research on ADHD in older adults, and until recently only a few case reports existed.Method: A systematic search was conducted in the databases Medline/PubMed and PsycINFO in order to identify studies regarding ADHD in adults ≥50 years.Results: ADHD persists into older ages in many patients, but the prevalence of patients fulfilling the criteria for the diagnosis at age ≥50 years is still unknown. It is reason to believe that the prevalence is falling gradually with age, and that the ADHD symptom level is significantly lower in the age group 70–80 years than the group 50–60 years. There is a lack of controlled studies of ADHD medication in adults ≥50 years, but this review suggests that many patients aged ≥50 years experience beneficial effects of pharmacological treatment. The problem with side effects and somatic complications may rise to a level that makes pharmacotherapy for ADHD difficult after the age of 65 years. Physical assessment prior to initiation of ADHD medication in adults ≥50 years should include a thorough clinical examination, and medication should be titrated with low doses initially and with a slow increase. In motivated patients, different psychological therapies alone or in addition to pharmacotherapy should be considered.Conclusion: It is essential when treating older adult patients with ADHD to provide good support based on knowledge and understanding of how ADHD symptoms have affected health, quality of life, and function through the life span. Individualized therapy for each elderly patient should be recommended to balance risk–benefit ratio when pharmacotherapy is considered to be a possible treatment. Keywords: ADHD, adults, older adults, pharmacotherapy, central stimulant