PATHOPHYSIOLOGY OF DEPRESSION: DO WE HAVE ANY SOLID EVIDENCE OF INTEREST TO CLINICIANS?

Due to the clinical and etiological heterogeneity of major depressive disorder, it has been difficult to elucidate its pathophysiology. Current neurobiological theories with the most valid empirical foundation and the highest clinical relevance are reviewed with respect to their strengths and weaknesses. The selected theories are based on studies investigating psychosocial stress and stress hormones, neurotransmitters such as serotonin, norepinephrine, dopamine, glutamate and gamma-aminobutyric acid (GABA), neurocircuitry, neurotrophic factors, and circadian rhythms. Because all theories of depression apply to only some types of depressed patients but not others, and because depressive pathophysiology may vary considerably across the course of illness, the current extant knowledge argues against a unified hypothesis of depression. As a consequence, antidepressant treatments, including psychological and biological approaches, should be tailored for individual patients and disease states. Individual depression hypotheses based on neurobiological knowledge are discussed in terms of their interest to both clinicians in daily practice and clinical researchers developing novel therapies.     

Ketamine modulates TRH and TRH-like peptide turnover in brain and peripheral tissues of male rats

Major depression is the largest single healthcare burden with treatments of slow onset and often limited efficacy. Ketamine, a NMDA antagonist used extensively as a pediatric and veterinary anesthetic, has recently been shown to be a rapid acting antidepressant, making it a potential lifesaver for suicidal patients. Side effects and risk of abuse limit the chronic use of ketamine. More complete understanding of the neurobiochemical mechanisms of ketamine should lead to safer alternatives. Some of the physiological and pharmacological actions of ketamine are consistent with increased synthesis and release of TRH (pGlu-His-Pro-NH₂), and TRH-like peptides (pGlu-X-Pro-NH₂) where “X” can be any amino acid residue. Moreover, TRH-like peptides are themselves potential therapeutic agents for the treatment of major depression, anxiety, bipolar disorder, epilepsy, Alzheimer's and Parkinson's diseases. For these reasons, male Sprague–Dawley rats were anesthetized with 162 mg/kg ip ketamine and then infused intranasally with 20 μl of sterile saline containing either 0 or 5 mg/ml Glu-TRH. One, 2 or 4 h later, the brain levels of TRH and TRH-like peptides were measured in various brain regions and peripheral tissues. At 1 h in brain following ketamine only, the levels of TRH and TRH-like peptides were significantly increased in 52 instances (due to increased biosynthesis and/or decreased release) or decreased in five instances. These changes, listed by brain region in order of decreasing number of significant increases (↑) and/or decreases (↓), were: hypothalamus (9↑); piriform cortex (8↑); entorhinal cortex (7↑); nucleus accumbens (7↑); posterior cingulate (5↑); striatum (4↑); frontal cortex (2↑,3↓); amygdala (3↑); medulla oblongata (1↑,2↓); cerebellum (2↑); hippocampus (2↑); anterior cingulate (2↑). The corresponding changes in peripheral tissues were: adrenals (8↑); epididymis (4↑); testis (1↑,3↓); pancreas (1↑); prostate (1↑). We conclude that TRH and TRH-like peptides may be downstream mediators of the rapid antidepressant actions of ketamine.     

Novel 5-HT7R antagonists,arylsulfonamide derivatives of (aryloxy)propyl piperidines: Add-on effect to the antidepressant activity of SSRI and DRI,and pro-cognitive profile

A novel series of arylsulfonamide derivatives of (aryloxy)propyl piperidines was designed to obtain potent 5-HT₇R antagonists. Among the compounds evaluated herein, 3-chloro-N-{1-[3-(1,1-biphenyl-2-yloxy)2-hydroxypropyl]piperidin-4-yl}benzenesulfonamide (25) exhibited antagonistic properties at 5-HT₇R and showed selectivity over selected serotoninergic and dopaminergic receptors, as well as over serotonin, noradrenaline and dopamine transporters. Compound 25 demonstrated significant antidepressant-like activity in the forced swim test (0.625–2.5 mg/kg, i.p.) and in the tail suspension test (1.25 mg/kg, i.p.), augmented the antidepressant effect of inactive doses of escitalopram (selective serotonin reuptake inhibitor) and bupropion (dopamine reuptake inhibitor) in the FST in mice, and similarly to SB-269970, exerted pro-cognitive properties in the novel object recognition task in cognitively unimpaired conditions in rats (0.3 mg/kg, i.p.). Such an extended pharmacological profile, especially the augmentation effect of the identified 5-HT₇R antagonist on SSRI activity, seems promising regarding the complexity of affective disorders and potentially improved outcomes, including mnemonic performance.     

Improving psychometric assessment of the Beck Depression Inventory using Multidimensional Item Response Theory

We studied the latent factor structure of the Beck Depression Inventory (BDI) under the light of Multidimensional Item Response Theory models. Under a Bayesian Markov chain Monte Carlo setting, we chose the most adequate model, estimated its parameters and verified its fit to the data. An evaluation of the inventory in terms of the assumed dimensions seems to agree with previous investigations in the factor structure of the BDI present in the literature. Cognitive and somatic‐affective latent traits were identified in the analysis making possible the interpretation of symptom evolution along these dimensions, in terms of probability of their appearance.     

Phase-Synchronization of Daily Motor Activities Can Reveal Differential Circadian Patterns

A patient diagnosed with seasonal affective disorder (SAD) carried out prospective ratings of depression weekly for nearly a decade. A winter peak of depression and benzodiazepine intake was documented. However, over the years, the depressive episodes shifted toward spring in an apparent free-running circannual rhythm (periodogram peaks at 53 and 55 weeks). This patient may have an underlying seasonal propensity to depression no longer precisely entrained to environmental cues. (Chronobiology International, 18(2), 309–313, 2001)     

文拉法辛联合认知行为疗法治疗帕金森病抑郁、认知功能障碍的临床疗效评价

目的:探讨文拉法辛联合认知行为疗法治疗帕金森病(PD)抑郁、认知功能障碍的临床疗效和安全性。方法:选择我院收治的60例PD合并抑郁、认知功能障碍患者并将其随机分为三组,分别为对照组(单用文拉法辛治疗),联合奥氮平组(文拉法辛联合奥氮平),联合认知行为疗法组(文拉法辛联合认知行为疗法),每组20例,于治疗前及治疗后4、8周末采用汉密尔顿抑郁量表(HAMD)进行抑郁程度评定,简易精神状态评价量表(MMSE)和事件相关电位(event-related potentials,ERPs)P300进行认知功能评定。结果:治疗4、8周时,三组的HAMD评分均较治疗前有不同程度下降,P300潜伏期较治疗前有不同程度缩短,P300波幅、MMSE评分有不同程度升高(P0.05),联合奥氮平组和联合认知行为疗法组HAMD评分较对照组明显下降,P300潜伏期较对照组明显缩短,P300波幅、MMSE评分明显升高(P0.05),联合认知行为疗法组HAMD评分较联合奥氮平组明显下降,P300潜伏期明显缩短,P300波幅、MMSE评分明显升高(P0.05)。三组均无特殊不良反应。结论:文拉法辛联合认知行为疗法治疗PD抑郁、认知功能障碍疗效确切,能显著改善患者抑郁症状,提高患者的认知功能,疗效较单用文拉法辛或文拉法辛联合奥氮平治疗更好,且安全性高。     

个性化心理护理对帕金森病伴抑郁状态患者的影响

目的探讨个性化心理护理对帕金森病患者伴抑郁状态的影响。方法选择我院神经内科收治的帕金森病伴抑郁状态患者100例作为研究对象,随机分成对照组和观察组各50例。对照组按帕金森病常规药物治疗和护理,观察组在此基础上给予个性化心理护理,观察两组患者4周后汉密尔顿抑郁量表(HAMD)评定情况。结果通过个性化心理护理后,观察组患者的抑郁发生率明显低于对照组,差异有统计学意义(P0.01)。结论个性化心理护理可显著改善帕金森病患者的抑郁症状,提高患者的生活质量。     

Effects of Insulin and Streptozotocin-Induced Diabetes on Brain Norepinephrine Metabolism in Rats

Administration of insulin (2 IU/kg, i.p.) produced a significant decrease (18%) in forebrain norepinephrine and a significant increase in the major metabolite of norepinephrine, 3-methoxy-4-hydroxyphenylglycol-sulfate (MOPEG-SO4, +19%) in rats. Streptozotocin-induced diabetes produced the opposite effects, resulting in an increase in forebrain norepinephrine (+17%) and a decrease in MOPEG-SO4 (-26%). In addition, insulin increased (+143%) and diabetes decreased (-41%) the turnover rate of norepinephrine, as measured by the rate of decrease of norepinephrine following inhibition of tyrosine hydroxylase by alpha-methyl-p-tyrosine. All of these effects in diabetic rats were reversed by insulin replacement therapy. These data are discussed within the context of mood disorders characteristic of diabetic patients.     

Design,synthesis and biological evaluation of novel serotonin and dopamine receptor ligands being 6-bromohexyl saccharine derivatives

Due to numerous side effects of current antidepressants, the search for new, safer bioactive compounds is still a valid research topic in medical chemistry. In our research we decided to synthesize and determine SAR for new hexyl arylpiperazines (LACPs) derivated with saccharin moiety. High biological activity has been explained using molecular modelling methods. The compounds obtained show high affinity for the 5-HT_1A (compound 18, K_i = 4 nM – antagonist mode) and D₂ (compound 15, K_i = 7 nM – antagonist mode) receptor, and in some cases also 5-HT₇ receptor (compound 17, K_i = 20 nM). A preliminary ADME analysis showed that the compounds exhibit CNS drugability properties. We have proved that carbon-chain lengthening may have a beneficial effect on increasing the activity towards serotonin and dopamine receptors.     

Culpa por percibirse como una carga. Una variable relevante asociada al malestar psicológico de las personas mayores

AimsTo analyze the relationship between guilt for perceiving oneself as a burden and negative self-perceptions of aging, perceived control and anxious and depressive symptomatology in older people without cognitive or functional limitations.MethodsParticipants were 351 community-dwelling people over 60 years without explicit cognitive or functional limitation. Indirect effet analysis were conducted that examined the indirect effect of negative self-perceptions of aging through 1) perceived control and anxious symptomatology and 2) perceived control and depressive symptomatology in guilt for perceiving oneself as a burden.ResultsBoth models showed an indirect relationship between negative self-perceptions of aging and guilt for perceiving oneself as a burden through 1) perceived control and anxious symptomatology and 2) perceived control and depressive symptomatology, explaining 26.37% of anxious symptomatology, 48.51% of depressive symptomatology and 13.73% and 14.44% of guilt for perceiving oneself as a burden, respectively.DiscussionThe results obtained suggest that higher negative self-perceptions of aging is associated with a lower perception of control and greater psychological distress (anxiety and depression), and this process increases the feeling of guilt for perceiving oneself as burden to family members in older people without functional or cognitive limitations.