Modern Trends in Pharmacopsychiatry

New neurons are continuously formed in the adult hippocampus of the human, nonhuman primate, and rodent throughout life though rates of neurogenesis precipitously decline with age to near zero levels at the end of the natural life span. Since its discovery in the 1960s, a large number of studies have documented numerous environmental and genetic factors which regulate adult neurogenesis. Chief among the positive regulators of neurogenesis are exercise and antidepressant drugs. Chief among the negative regulators of neurogenesis besides age are stress and inflammation...

The concept of neuroprogression describes the progressive course of the disorder and stresses the progressive, recurrent, and chronic course of the disease entity under consideration. It subsumes clinical manifestations of the disease process and may also entail morphological, biochemical, neurochemical, immunological, physiological, and genetic aspects that contribute to the progressive course of the disease in question. In an attempt to identify the appropriate agent or method that could arrest neuroprogression in psychiatric patients, we conducted an evaluation of the use of anti-inflammatory drugs under the perspective of current pharmacological and neurophysiological data...

Prevention of deterioration of brain function over time is important in the long-term management of chronic brain disorders such as dementia, schizophrenia, and mood disorders. Although the possibility of neurogenesis in the adult human brain is attractive, and there are psychiatric drugs proven to be effective inducers of neurogenesis in animals, we have yet to see their utility in clinical practice. The terms neurodegeneration and neuroregeneration are often used in a nonspecific manner. Neuroregeneration may mean neurogenesis, dendritogenesis, spinogenesis, or axonogenesis...

Schizophrenia is a disorder that shows a progressive course in 30-50% of the people concerned. The biology of chronification and progression is unclear. Genetic aspects may play a role, but details are unresolved. The fact that immune-mediated and autoimmune disorders such as rheumatoid arthritis or multiple sclerosis have a very similar course as schizophrenia has focused the interest on the immunopathogenesis of schizophrenia. A clear immune marker for neuroprogression in schizophrenia or psychosis could not be identified up to now, but a proinflammatory immune state (increased markers of cellular immunity) is regularly found in schizophrenia, e...

Several studies suggest that major depressive disorder (MDD) and bipolar disorder (BPD) are neuroprogressive illnesses. Besides clinical features, neurobiological mechanisms have been suggested to contribute to the neuroprogression of mood disorders. Biological factors that have been shown to contribute significantly toward the neuroprogressive course of these disorders are inflammatory markers, such as cytokines. Cytokines have been extensively investigated, primarily in the serum of MDD and BPD patients, and these studies show cytokine abnormalities in both adolescent and adult patients with mood disorders...

Neuroprogression is a term used to describe worsening psychopathology, poor treatment response, and declining cognitive and functional outcomes among patients with chronic mental disorders. Chronic inflammatory activation and glutamate-mediated excitotoxicity are two key etiological factors implicated in the development of neuroprogression. In this chapter, we hypothesize that the association between chronic inflammatory activation, neuroprogression, and glutamate dysregulation might be mediated by glial dysfunction...

Epidemiological studies implicate chronic depression as a predisposing factor for dementia in later life. However, the link is incompletely understood and controversial. The aim of this review is to consider some of the biological factors that contribute to neuroprogressive brain dysfunction in late life as a consequence of prolonged, low-grade inflammation in the course of depressive episodes. As chronic inflammation is known to precipitate increased apoptosis of neurons and astrocytes, this could be a contributing factor to brain dysfunction...

Psychotic disorders are heterogeneous and complex, involving many putative causal factors interacting along the course of disease development. Many of the factors implicated in the pathogenesis of psychosis also appear to be involved in disease onset and subsequent neuroprogression. Herein, we highlight the pertinent literature implicating inflammation and oxidative stress in the pathogenesis of psychosis, and the potential contribution of N-methyl-D-aspartate receptors (NMDARs). We also emphasize the role of peripubertal social stress in psychosis, and the ways in which hippocampal dysfunction can mediate dysregulation of the hypothalamic-pituitary-adrenal axis and cortisol release...

Immunostimulatory insults such as stress and infection are risk factors for the development of several neuropsychiatric disorders characterized by neuroprogression. Inflammatory and neurotoxic molecules in the brain can cause disruptions in neurogenesis, neuronal excitability, synaptic transmission, synaptic plasticity, and neuronal survival - changes that characterize neuroprogression. We draw on recent findings in the immunology literature that peripheral innate immune cells are capable of retaining long-term memory of infectious insults and displaying long-lasting upregulated proinflammatory function in response to repeated infectious insults - a concept known as "innate immune memory...

Traditionally, the neurobiology of major depressive disorder (MDD) has been largely considered from the perspective of the state of major depressive episodes (MDE) versus being in remission, but the current accumulation of disease markers, largely acquired cross-sectionally, is strongly suggestive of neuroprogressive aspects of MDD. This chapter focuses on the changes in disease markers involved in the reorganization of the nervous system in MDD, including the translocator protein (TSPO; an index of microglial activation), glial fibrillary acidic protein (GFAP; an index of astroglial activation), [11C]harmine (a marker of monoamine oxidase A; MAO-A), and several other indices (metabotropic glutamate receptor 5 [mGluR5], excitatory amino acid transporters, and magnetic resonance imaging spectroscopy measurements) of glutamate dysregulation...

There is a growing emphasis on the relationship between the complexity and diversity of the microorganisms that inhabit our gut (human gastrointestinal microbiota) and brain health. The microbiota-gut-brain axis is a dynamic matrix of tissues and organs including the brain, glands, gut, immune cells, and gastrointestinal microbiota that communicate in a complex multidirectional manner to maintain homeostasis. Changes in this environment may contribute to the neuroprogression of stress-related disorders by altering physiological processes including hypothalamic-pituitary-adrenal axis activation, neurotransmitter systems, immune function, and inflammatory responses...

Treatment refractoriness remains one of the biggest challenges in the field of bipolar disorder (BD) as treatments are often suboptimal or unsatisfactory. Recent evidence points towards a potential link between the progressively evolving nature of BD, increased inflammation, and reduced treatment response. There are several medications and other somatic treatments available, but remission rates are low, and medication compliance is still problematic. Psychotherapeutic techniques appear to be promising in several disease states and in relapse prevention, but additional research is needed to determine who will benefit from what strategy the most...

Although it is well known that there is a high degree of comorbidity between chronic pain and mood and anxiety disorders, the mechanisms involved in these co-occurrences are not clear. It appears that numerous neurotransmitters and neuromodulators are involved, and this chapter focuses on the monoamine neurotransmitters noradrenaline, 5-hydroxytryptamine (5-HT, serotonin), and dopamine and the amino acid neurotransmitters GABA (γ-aminobutyric acid) and glutamate in chronic pain and depression. Numerous preclinical and clinical neurochemical, neuroanatomical, pharmacological and molecular biological studies as well as clinical pharmacological treatment investigations implicate noradrenaline, 5-HT and, to a lesser extent, dopamine in the etiology of pain and depression...

Neuropathic pain occurs as a result of lesion or disease affecting the somatosensory nervous system and is present in a diverse set of peripheral and central pathologies such as nerve trauma, diabetic neuropathy, post-herpetic neuralgia, chemotherapy-induced peripheral neuropathy, spinal cord injury and multiple sclerosis. Debilitating symptoms including allodynia, hyperalgesia and spontaneous pain have a substantial negative impact on patients' quality of life. The currently available therapeutic treatments are generally ineffective and characterised by poor response rates...

Pain processing in patients with borderline personality disorder (BPD) is abnormal primarily with respect to pain thresholds which are typically elevated or perception of phasic nociceptive stimuli which is reduced. In spite of this common finding, nonsuicidal self-injury (NSSI), often expressed as cutting, is a hallmark sign of the disease and serves to release aversive inner tension. The question thus arises, how does a painful stimulus release inner tension when these patients feel less pain than healthy people? However, intensity discrimination is normal in these patients...

Depression and chronic pain have been estimated to co-occur in up to 80% of patients suffering from these disorders, with this co-morbidity being more disabling and more expensive to both patients and society than either disorder alone. A number of neural substrates have been proposed to underlie this association; however, there has been increased interest and support for a role of neuroimmune and neuroinflammatory mechanisms as key players in this dyad. This chapter will provide an overview of the clinical and preclinical data supporting a role for neuroimmune alterations in depression-pain co-morbidity...

Co-morbid depression and chronic pain are highly prevalent. The purpose of this review is to examine the role of chronic inflammation as a common mediator of these co-morbidities. Dysfunctional bidirectional pathways between the brain and the immune, endocrine and neurotransmitter systems have been extensively described and implicated in pain and psychiatric disorders. This short review therefore accesses the evidence in favour of the psychoneuroendocrine hypothesis of psychiatric disorders under three main headings: (1) by illustrating how different types of stress play a crucial role in initiating chronic inflammation in major depression, (2) by accessing the evidence that pain is frequently an important component of, and an initiator of, depression, and (3) considering the evidence that chronic inflammation provides an important link between chronic pain and depression, and the possible cellular mechanisms involved in this process...

In this article, the co-occurrence of anxiety disorders (in particular generalized anxiety disorder) and pain conditions is described, characteristics of chronic pain are explained, and data on the prevalence of co-comorbidity of both conditions are reviewed. Further, hypotheses on the possible psychosocial and neurobiological backgrounds of the high rate of co-occurrence are discussed. This review will also focus on the role of 'unexplained' pain syndromes (e.g. somatic symptom disorder and fibromyalgia) and anxiety...

Animal models of chronic pain have provided valuable information on the mechanisms of initiation and maintenance of the disease. Much of the research effort has targeted sensory abnormalities like hyperalgesia and allodynia. However, in the past 15 years a significant number of research groups have focused their attention on comorbid anxiety, depression and cognitive impairments that frequently emerge in chronic pain conditions. A myriad of paradigms have since then been introduced in the field to tackle multiple dimensions of rodents' behavior...

Multiple emotional and cognitive factors impact on the experience of pain. This chapter will review some of the most important emotional and cognitive determinants of the pain experience as found in experimental and clinical studies with human participants. Emotional factors that may increase pain perception are anxiety, depression and anger. Positive emotions usually decrease perceived pain. The cognitive factors attention, expectancy and appraisal can either increase or decrease pain experiences depending on their specific focus and content...