The Psycho-Neurology of Cross-Species Affective/Social Neuroscience: Understanding Animal Affective States as a Guide to Development of Novel Psychiatric Treatments

Neurogenetics and Epigenetics of Loneliness

Loneliness, an established risk factor for both, mental and physical morbidity, is a mounting public health concern. However, the neurobiological mechanisms underlying loneliness-related morbidity are not yet well defined. Here we examined the role of genes and associated DNA risk polymorphic variants that are implicated in loneliness via genetic and epigenetic mechanisms and may thus point to specific therapeutic targets. Searches were conducted on PubMed, Medline, and EMBASE databases using specific Medical Subject Headings terms such as loneliness and genes, neuro- and epigenetics, addiction, affective disorders, alcohol, anti-reward, anxiety, depression, dopamine, cancer, cardiovascular, cognitive, hypodopaminergia, medical, motivation, (neuro)psychopathology, social isolation, and reward deficiency. The narrative literature review yielded recursive collections of scientific and clinical evidence, which were subsequently condensed and summarized in the following key areas: (1) Genetic Antecedents: Exploration of multiple genes mediating reward, stress, immunity and other important vital functions; (2) Genes and Mental Health: Examination of genes linked to personality traits and mental illnesses providing insights into the intricate network of interaction converging on the experience of loneliness; (3) Epigenetic Effects: Inquiry into instances of loneliness and social isolation that are driven by epigenetic methylations associated with negative childhood experiences; and (4) Neural Correlates: Analysis of loneliness-related affective states and cognitions with a focus on hypodopaminergic reward deficiency arising in the context of early life stress, eg, maternal separation, underscoring the importance of parental support early in life. Identification of the individual contributions by various (epi)genetic factors presents opportunities for the creation of innovative preventive, diagnostic, and therapeutic approaches for individuals who cope with persistent feelings of loneliness. The clinical facets and therapeutic prospects associated with the current understanding of loneliness, are discussed emphasizing the relevance of genes and DNA risk polymorphic variants in the context of loneliness-related morbidity.

The Human Affectome Project: A dedication to Jaak Panksepp

Mapping the neural basis of the Affectome was certainly the goal of Jaak Panksepp as he extended the work of a long line of thinkers from William James to Paul Maclean. Jaak's contribution was not just an incremental step, but a move to embrace feelings as a key component of affective science. His goal was to develop objective behavioral measures as he identified the neural substrates associated with affective states. He dedicated his career to studying the biological roots of emotional operating systems and his 1998 book "Affective Neuroscience" stands as a seminal accomplishment that provided a foundation for a field of research that has flourished since. His influences can be seen in many of the reviews created for this project and his early references to comfort zones are central to the human affectome. Indeed, Jaak was a tireless investigator who challenged our thinking, and he gave us many insights and gifts. We are immensely grateful for his contributions and this special issue is dedicated to his memory.

Loneliness-based impaired reward system pathway: Theoretical and clinical analysis and application

Loneliness is a key determinant in the etiology of mental health disorders such as depression and has profound impacts on health, quality of life, and economic productivity. This narrative review uses extant neurobiology and evolutionary literature to propose a construct through which loneliness may induce depression in adulthood via the reward system (including symptom and treatment aspects). Early childhood (distal) factors were found to be important in influencing adult (proximal) factors, which lead to the formulation of the construct. Due to the heterogenous and comorbid nature of depression, a new subtype known as 'reward depression' was distinguished along with distinct symptoms to aid practitioners when assessing patient treatment options. Furthermore, an evolutionary perspective was applied to the current impaired reward construct to discuss how the ancestral purpose and environment (in terms of reward) clashes with the modern one. Finally, theoretical treatment and prevention ideas were examined and discussed, leading into future work that needs to build upon and confirm the outlined construct.

Nonsuicidal Self-Injury and Suicidal Behaviors in Girls: The Case for Targeted Prevention in Preadolescence

Non-suicidal self-injury (NSSI) affects 15-20% of adolescents-disproportionately girls-and is a strong predictor of eventual suicide attempts and suicide. Many girls now initiate NSSI before age 10. These early-starters exhibit greater frequency of NSSI, use more diverse methods, and are hospitalized more often, yet there are no empirically supported prevention programs for preadolescents. Obstacles to prevention include ascertaining who is sufficiently vulnerable and specifying mechanistic intervention targets. Recent research indicates that (1) preadolescent girls with ADHD who are also maltreated are at alarming risk for NSSI and suicide attempts by adolescence, and (2) the conjoint effects of these vulnerabilities are sufficiently potent for targeted prevention. Research also indicates that existing interventions are effective in altering child- and family-level mechanisms of NSSI. These interventions alter neurobiological markers of vulnerability, which can be used as proximal efficacy signals of prevention response, without waiting for NSSI and suicide attempts to emerge.

Behavioral awareness in the feline consultation: Understanding physical and emotional health

Practical relevance: Awareness of the strong connection between observed behavior and physical and emotional health is essential for patient welfare. It is often a change in the individual's normal behavior that informs owners and veterinarians of the possibility of illness, pain and stress/distress. There is ample evidence in the feline literature that medical and behavioral health go hand in hand. In most feline cases, medical and behavioral conditions contribute concurrently to clinical signs. Clinical challenges: Our domestic cats do not express change in physiological and emotional states in a way that is easily recognized. Therefore, it can be difficult to diagnose medical and behavioral illnesses and ascertain contributions from each one to the final diagnosis. When various levels of stress are present, especially distress, this compromises behavioral and physical health, and influences treatment outcomes.

AIMS

This review is intended to help veterinarians recognize physical and behavioral changes associated with acute stress through to chronic distress, including stress-associated diseases. An emphasis on thorough history-taking will allow the clinician to ascertain which signs are behavioral and which are medical, with the understanding that they are not mutually exclusive. Equally important is the contribution of pain, chronic disease and poor environmental situations to behavioral changes and the expression of medical disorders. Evidence base: There is an increasing amount of evidence that stress and distress have profound effects on feline health, behavior and welfare. The authors have drawn on a substantial body of published veterinary research in producing this review.

Animal models of depression: pros and cons

Animal models of depression are certainly needed but the question in the title has been raised owing to the controversies in the interpretation of the readout in a number of tests, to the perceived lack of progress in the development of novel treatments and to the expressed doubts in whether animal models can offer anything to make a true breakthrough in understanding the neurobiology of depression and producing novel drugs against depression. Herewith, it is argued that if anything is wrong with animal models, including those for depression, it is not about the principle of modelling complex human disorder in animals but in the way the tests are selected, conducted and interpreted. Further progress in the study of depression and in developing new treatments, will be supported by animal models of depression if these were more critically targeted to drug screening vs. studies of underlying neurobiology, clearly stratified to vulnerability and pathogenetic models, focused on well-defined endophenotypes and validated for each setting while bearing the existing limits to validation in mind. Animal models of depression need not to rely merely on behavioural readouts but increasingly incorporate neurobiological measures as the understanding of depression as human brain disorder advances. Further developments would be fostered by cross-fertilizinga translational approach that is bidirectional, research on humans making more use of neurobiological findings in animals.

Tools for Managing Feline Problem Behaviours Psychoactive medications

PRACTICAL RELEVANCE

When a cat is presented for evaluation of a problem behaviour, it is likely that the cat's wellbeing is negatively affected by the condition. In addition, the owners and any other animals around the cat may also be experiencing negative consequences. When managing these cases, it is important to consider all options (including behaviour modification, environmental changes, medications) that can help to reach an optimal solution. Medication cannot teach the cat how to behave or change a particular behaviour; it can, however, reduce arousal, excitability, reactivity and anxiety.

RATIONALE

The rationale for using psychoactive medications in behavioural medicine, or veterinary psychiatry, is to increase the wellbeing of the animal and to aid the owner and practitioner in managing problem behaviours. Medications should always be used as an adjunct to behavioural and environmental modification.

CLINICAL CHALLENGES

Many psychoactive medications cannot be used in the face of certain physical illnesses or concurrently with other medications. Some medications may also have side effects, not be effective at the recommended dose or have a paradoxical effect. Furthermore, success is reliant on the owner being able to administer the medication.

AIMS

This article aims to guide practitioners by discussing questions such as how to choose the appropriate medication, how to dose it and how long to use it. The psychoactive medications most commonly used in feline medicine are reviewed, as well as some that are newer or less common.

EVIDENCE BASE

Data for the use of medications in cats is limited, with just a small number of clinical-, species- and problem-directed studies available, and a few more case series and case reports. Where feline-specific research is not available, the authors have drawn upon research published in other species, such as humans, dogs and rats, as well as anecdotal reports and expert opinions.

Using the research domain criteria (RDoC) to conceptualize impulsivity and compulsivity in relation to addiction

Nomenclature for mental disorder was updated in 2013 with the publication of the fifth edition of the Diagnostic and Statistical Manual (DSM-5). In DSM-5, substance use disorders are framed as more dimensional. First, the distinction between abuse and dependence is replaced by substance use. Second, the addictions section now covers both substances and behavioral addictions. This contemporary move toward dimensionality and transdiagnosis in the addictions and other disorders embrace accumulating cognitive-affective neurobiological evidence that is reflected in the United States' National Institutes of Health Research Domain Criteria (NIH RDoC). The RDoC calls for the further development of transdiagnostic approaches to psychopathy and includes five domains to improve research. Additionally, the RDoC suggests that these domains can be measured in terms of specific units of analysis. In line with these suggestions, recent publications have stimulated updated neurobiological conceptualizations of two transdiagnostic concepts, namely impulsivity and compulsivity and their interactions that are applicable to addictive disorders. However, there has not yet been a review to examine the constructs of impulsivity and compulsivity in relation to addiction in light of the research-oriented RDoC. By doing so it may become clearer as to whether impulsivity and compulsivity function antagonistically, complementarily or in some other way at the behavioral, cognitive, and neural level and how this relationship underpins addiction. Thus, here we consider research into impulsivity and compulsivity in light of the transdiagnostic RDoC to help better understand these concepts and their application to evidence-based clinical intervention for addiction.