Depression Biological features

The older MAOIs (e.g. phenelzine) may be more effective than other classes in atypical depression, a form of depressive illness where mood reactivity is preserved, lack of energy may be extreme and biological features are the opposite of the normal S3mdrome i.e. excess sleep and appetite with weight gain. 

In its pure form, reactive depression can present with severe levels of symptomatology, yet basic physical functions (sleep, energy levels, and so on) are relatively unaffected. Note that many reactive depressions do take on biological features, as will be described below, but the pure reactive disorder noted here is seen without major physiological symptoms. 

Substantial evidence supports the theory that psychotic depression represents a distinct type of major depression (Schatzberg and Rothschild 1992). Statistically significant differences between psychotic and nonpsychotic major depression have been noted along many axes, including presenting features (Coryell et al. 1984 Frances et al. 1981 Classman and Roose 1981 Lykouras et al. 1986 J. C. Nelson and Bowers 1978), biology (Carroll et al. 1976a Coryell et al. 1982 Rihmer et al. 1984 Rudorfer et al. 1982), familial transmission (Leckman et al. 1984 W. H. Nelson et al. 1984), course of illness (D. G. Robinson and Spiker 1985), and response to treatment (Chan et al. 1987 Classman and Roose 1981 Kantor and Classman 1977 J. C. Nelson and Bowers 1978 Rothschild 1985). 

In clinical studies, major depressive disorder has had four specifiers, including melancholic feature, atypical feature, catatonic feature, and postpartum onset. In the future, we should investigate the distributions of the four specifiers of depression among patients with physical illness and discuss which biological markers could link the depressive disorder and the physical illness. 

It has been reported that the toxic depressant concentration of such a drug bears a close resemblanee with the physical features, namely partition coefficient, solubility, vapour pressure and surfaee aetivity. As most of these characteristics are entirely based on an equilibrium phenomenon, the ultimate effeets of the drug on the biological system are directly linked to an equilibrium model. 

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