Major depressive disorder systems

NEUROTRANSMITTER AND NEUROPEPTIDE SYSTEMS ARE IMPLICATED IN THE PATHOPHYSIOLOGY OF BIPOLAR AND MAJOR DEPRESSIVE DISORDERS 889... 

It also seems likely that some mental disorders (perhaps major depressive disorder) in their present form will fail to show evidence of taxonicity, but definitional refinement would help elucidate underlying taxa (e.g., melancholia). Thus, taxometrics may be able to serve as an impetus and a guide for revising the diagnostic system. Of course, taxometric methods alone are not sufficient to tackle this task and should be used in conjunction with dimensional methods, such as exploratory factor analysis. Dimensions provide the building blocks for construction of taxa, and research on the structure of psychopathology should integrate dimensional and taxometric methods. 

The burden of mental illness has traditionally been underestimated worldwide. Despite treatment advances, major depressive disorder (MDD) is still a significant cause of morbidity and mortality. In fact, depression was the fourth leading cause of disease burden in the world in 1990, and is projected to be the second leading cause of disability by 2020. In the United States alone, it causes billions of dollars annually in direct and indirect medical costs and losses in productivity. It is now known that patients with MDD may experience both psychological and medical complaints, including pain, which underscores the severity of impact of MDD on the health-care system. 

Amsterdam, J. D. (2003), A double-blind, placebo-controlled trial of the safety and efficacy of selegiline transdermal system without dietary restrictions in patients with major depressive disorder,/. Clin. Psychiatry, 64(2), 208-214. 

The other specifiers for the major depressive disorder (with melancholic features, with postpartum onset, etc.) cannot be coded within the numbering system. They are to be written out and listed after the official diagnosis. 

The electroconvulsive therapy performed in the past is a far cry from the process used today in the treatment of major depressive disorder. In ECT a generalized central-nervous-system seizure is induced by means of an electric current. The objective is to achieve the full seizure threshold until the full therapeutic gains can be established. The exact process by which ECT works is unknown however, the shock results in an increase in different neurotransmitter responses at the cell membrane. Four to twelve treatments are generally given until therapeutic results are noted (Sachs, 1996). 

Amine hypothesis of mood The hypothesis that major depressive disorders result from a functional deficiency of norepinephrine or serotonin at synapses in the central nervous system... 

Monoamine oxidase inhibitors, such as SSRIs, have been shown to be effective in the treatment of depression, and they have become among the most widely used prescription drugs in the United States. Prozac is used not only to treat major depressive disorders but also bulimia nervosa, obsessive-compulsive disorder, panic disorder, and premenstrual dysphoric disorder. Multiple serotonin receptor subtypes are involved. Specific serotonin receptor subtype agonists and antagonists have been radiolabeled with positron-emitting tracers to assess the state of the serotonergic system. 

Norepinephrine (NE) is a major neurotransmitter in both the central and peripheral nervous system and is involved in regulation of a variety of body functions. Extracellular levels of norepinephrine can be increased by blocking its reuptake by the norepinephrine transporter (NET). Drugs that inhibit norepinephrine reuptake either selectively or in combination with serotonin or dopamine have demonstrated efficacy in the clinic for a variety of indications such as attention deficit hyperactivity disorder (ADHD), major depressive disorder (MDD), pain disorders (e.g. fibromyalgia), and vasomotor symptoms (VMS). In an effort to identify new selective NRIs, we designed a novel class of 1-(3-amino-1-phenylpropyl)indolin-2-ones. These compounds showed potency inhibiting NE reuptake when tested in the human norepinephrine transporter (hNET) inhibition assay. The compounds also showed selectivity (>100) against the human serotonin and dopamine transporters. The synthesis and properties of these novel compounds are described. 

The serotonergic system has long been thought to play a role in major depression and bipolar disorders, although the exact mechanisms are yet to be determined 889... 

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