Потенциальные механизмы лечения депрессии

EMERGING THERAPEUTIC TARGETS


Consider the following novel mechanisms that may become the basis for creating entirely new antidepressants in the foreseeable future, by design, not by serendipity:

• corticotropin-releasing factor (CRF) and glucocorticoids

         – CRF antagonists
           – vasopressin receptor antagonists
           – glucocorticoids as agonists or antagonists

• neurokinin system
• brain derived neurotropic factor (BDNF) and other neurotropins, such as fibroblast growth factor (FGF) or vascular endothelial growth factor (VEGF)
• phosphodiesterase inhibitors
• glutamate pathway modulators

        – ketamine (IV infusion with immediate efficacy)
          – α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic (AMPA) receptor modulators
          – glycine

• hypothalamic feeding peptides
• circadian gene products
• other evolving antidepressants

        – K-opioid receptor antagonists
          – CB1 cannabinoid receptor agonists/antagonists
          – cytokines
          – melatonin receptor agonists
          – galanin
          – neuropeptide Y
          – histone deacetylase inhibitors
          – tissue plasminogen activator

 The hazards of serendipity

Нарушения дыхания во сне и психиатрические расстройства

The mechanism(s) underlying the connection between SDB and psychiatric symptoms is a matter of debate. From a psychiatric perspective, one can conceptualize the relationship as stemming from a direct physiological consequence of the general medical condition (in this case, sleep deprivation and nocturnal hypoxia/hypercapnia). Therefore, the increased prevalence of depression with SDB would not be surprising given that such a relationship is seen in other diseases that produce hypoxia and impair quality of life (eg, chronic obstructive pulmonary disease). On the other hand, excessive sleepiness and fatigue as a result of sleep apnea produce significant social and personal problems and result in depression. Ishman and colleagues showed that the daytime sleepiness is a strong predictor of depressive symptoms in patients with SDB.

Sleep apnea and depression can be bridged conceptually by vital exhaustion. Vital exhaustion refers to a state characterized by elevated somatic and cognitive symptoms of depression without affective symptoms. Our group as well as others demonstrated that vital exhaustion profiles were affected in patients with SDB. Therefore, depressive manifestations in patients with sleep apnea may reflect the patients’ vital exhaustion, which differs dramatically from melancholic affective mood changes observed in more typical forms of depression and dysthymia. As such, depressive phenomena in patients who have sleep apnea should be more akin to depression secondary to chronic medical illness.

The Correlation Between Sleep-Disordered Breathing and Psychiatry 

Профиль препарата JNJ-37822681

JNJ-37822681 is a novel, fast-dissociating dopamine D2 receptor antagonist, currently in development as an antipsychotic drug candidate. A previous first-in-human study demonstrated mild central nervous system effects of JNJ-37822681 in healthy male volunteers. Significant but transient serum prolactin elevations were demonstrated, whereas other neurophysiological effects were relatively small. To investigate striatal dopamine D2 receptor occupancy by variable single doses of JNJ-37822681, an open-label [11C]raclopride positron emission tomography study was performed in 12 healthy male volunteers, using the simplified reference tissue model with cerebellum as reference tissue. Oral administration of JNJ-37822681 resulted in dose-dependent dopamine D2 receptor occupancy. Receptor occupancy increased from 9–19% at 2 mg doses to 60–74% at 20 mg doses of JNJ-37822681. Therefore, single oral doses of JNJ-37822681 can produce occupancy levels that are generally associated with clinical efficacy for registered antipsychotic drugs.

In vivo quantification of striatal dopamine D2 receptor occupancy by JNJ-37822681 using [11C]raclopride and positron emission tomography 

Using the rate of dissociation from the D2 receptor as a means to screen novel compounds for antipsychotic drug candidates, the centrally acting and fast-dissociating selective dopamine D2 receptor antagonist JNJ-37822681 was developed. In a blinded, placebo-controlled, randomized first-in-human study, JNJ-37822681 was administered orally to 27 healthy male volunteers at doses of 0.5, 2, 5, 10, 15 and 20 mg. Safety, pharmacokinetics and central nervous system effects were evaluated by measuring prolactin levels, eye movements, adaptive tracking, visual analogue scales, body sway, finger tapping and electroencephalography. JNJ-37822681 was well tolerated and somnolence was the most frequently reported adverse effect. Peak plasma concentrations increased more than proportional to dose, but increases in the area under curve (AUC) were dose-proportional. Prolactin elevations started at doses of 5 mg, whereas small decreases in adaptive tracking were demonstrated at 10 mg doses. At higher doses, JNJ-37822681 caused a small decrease in saccadic peak velocity, smooth pursuit, alertness, finger tapping and electroencephalography activity, and an increase in body sway. This effect profile is likely to be the result of the selectivity of JNJ-37822681 for the D2 receptor, leading to strong D2 receptor-mediated elevations in serum prolactin, but fewer effects on more complex central nervous system functions, which are likely to involve multiple neurotransmitters.

Pharmacokinetics and central nervous system effects of the novel dopamine D2 receptor antagonist JNJ-37822681 

Препарат LY2140023 не превзошел по эффективности плацебо

Eli Lilly (LLY) announced Wednesday that its schizophrenia drug candidate didn't do better than the placebo in a phase-two study.

The study in question looked at the drug, called pomaglumetad methionil, as the sole treatment for the mental disease, but another ongoing trial is still studying the compound as a supplemental treatment with other medicines. Lilly said that trial is complete, but it's still awaiting results.

 Lilly's Schizophrenia Drug Candidate Fails Trial

Сравнение CDSS и HAMD-17 у больных шизофренией

Background: The aim of this study was to compare two measures of depression in patients with schizophrenia and schizophrenia spectrum disorder, including patients with delusional and schizoaffective disorder, to conclude implications for their application.

Sampling and Methods: A total of 278 patients were assessed using the Calgary Depression Scale for Schizophrenia (CDSS) and the Hamilton Depression Rating Scale (HAMD-17). The Positive and Negative Syndrome Scale (PANSS) was also applied. At admission and discharge, a principal component analysis was performed with each depression scale. The two depression rating scales were furthermore compared using correlation and regression analyses. 

Results: Three factors were revealed for the CDSS and HAMD-17 factor component analysis. A very similar item loading was found for the CDSS at admission and discharge, whereas results of the loadings of the HAMD-17 items were less stable. The first two factors of the CDSS revealed correlations with positive, negative and general psychopathology. In contrast, multiple significant correlations were found for the HAMD-17 factors and the PANSS subscores. Multiple regression analyses demonstrated that the HAMD-17 accounted more for the positive and negative symptom domains than the CDSS.

Conclusions: The present results suggest that compared to the HAMD-17, the CDSS is a more specific instrument to measure depressive symptoms in schizophrenia and schizophrenia spectrum disorder, especially in acutely ill patients.

Evaluating Depressive Symptoms in Schizophrenia: A Psychometric Comparison of the Calgary Depression Scale for Schizophrenia and the Hamilton Depression Rating Scale

Пример неэффективности лечения шизофрении витаминно-минеральными комплексами и анализ доказательной базы БАДов Truehope

A B.C. Supreme Court judge will decide if a schizophrenic man who killed his father and injured his mother while taking multivitamins instead of his anti-psychotic medication is criminally responsible for the attack.

 Mentally ill killer tried vitamin therapy, court told

However, there is no doubt that vitamin deficiencies can produce neurological and psychiatric disturbances. For instance, a lack of B12 can damage the central nervous system via changes in cytokine and growth factor production (Scalabrino, 2009). Thiamine deficiency is well-known for causing Wernicke's encephalopathy and Korsakoff's syndrome, disorders characterized by severe memory impairments. Previous studies have suggested that vitamins and minerals do have an effect on mood and perhaps even antisocial behavior Kaplan et al., 2007; Bohannon, 2009). The question here is whether broad-spectrum micronutrient treatments (i.e., nutritional supplements) can improve or "cure" bipolar disorder.

Truehope lists 17 published studies on the effectiveness of EMPowerplus™ in treating bipolar, ADHD, autism, and OCD. However, none of these studies is a randomized controlled trial that compares placebo to EMPowerplus™ in a double-blind fashion. Thus, it cannot be established that any improvements are due to the supplement, rather than to expectation or placebo effects.

EMPowered to Kill

Did "Alternative Medicine" Lead to Murder?

Меланокортин и ангедония

The researchers report that chronic stress in mice leads to activation of the melanocortin 4 receptor, which decreases the strength of excitatory synapses on neurons expressing D1 dopamine receptor in the nucleus accumbens, the brain's pleasure center.

The research also shows that stress-elicited increases in behavioral measurements of anhedonia in the mice can be prevented by blocking melanocortin 4 receptor–mediated synaptic changes in the animals.

"By delineating the molecular mechanisms underlying the circuit modifications that mediate specific behavioural manifestations of psychiatric symptoms such as anhedonia, it should be possible to accelerate the development of efficacious therapies with new mechanisms of action," the investigators write.

Hormone a New Treatment Target for Depression, Schizophrenia?