Depression: Few lesser known causes

Cognitive deficits and elevated cortisol level are considered as the hallmark of depression. Actual causative factor for cognitive changes and depression are not well understood. Various studies summarize one or other factors like cortisol in causation of cognitive changes and depression. However complete model based study is required signifying all the causative factors. Hippocampus in brain is closely related to cognitive functions. As mineralocorticoid and glucocorticoid receptors are present majorly in hippocampus through which cortisol exerts its action. So the association of cortisol with depression and cognitive changes is emphasized more till date. In time, depression and cognitive changes development has changed from age related to stress related and later to more complex mechanisms like immune reaction. Stressful life event in various studies had been correlated with increased cortisol level which they considered as the main biological factor. But other factors like immune reaction, IDO pathway, 5-HT precursor tryptophan may equally contribute in development of these changes. Sum up of all factors in an individual is more important in development of cognitive deficits and depression. So a newer approach should be designed considering other factors summarized in this review to develop a model based approach.