Depressed patients in the community appear to have increased early morning cortisol secretion, but the demonstration of this effect requires control for time of waking.
Greater secretion of cortisol may be present in depressed subjects after clinical recovery and withdrawal of medication. This may put patients at risk of further episodes of depression as well as comorbid medical conditions, such as coronary heart disease.
In addition to causing distress and disability to the individual, neuropsychiatric disorders are also extremely expensive to society and governments. These disorders are both common and debilitating and impact on cognition, functionality and wellbeing. Cognitive enhancing drugs, such as cholinesterase inhibitors and methylphenidate, are used to treat cognitive dysfunction in Alzheimer's disease and attention deficit hyperactivity disorder, respectively. Other cognitive enhancers include specific computerized cognitive training and devices. An example of a novel form of cognitive enhancement using the technological advancement of a game on an iPad that also acts to increase motivation is presented. Cognitive enhancing drugs, such as methylphenidate and modafinil, which were developed as treatments, are increasingly being used by healthy people. Modafinil not only affects ‘cold’ cognition, but also improves ‘hot’ cognition, such as emotion recognition and task-related motivation. The lifestyle use of ‘smart drugs' raises both safety concerns as well as ethical issues, including coercion and increasing disparity in society. As a society, we need to consider which forms of cognitive enhancement (e.g. pharmacological, exercise, lifelong learning) are acceptable and for which groups (e.g. military, doctors) under what conditions (e.g. war, shift work) and by what methods we would wish to improve and flourish.
These findings are similar to the effects of conventional antidepressants and opposite to the negative biases in depression. The central effects of Epo therefore deserve further investigation as a potential antidepressant mechanism.
The primary role of the orexins was originally believed to be appetite regulation, but is now believed to be the regulation of sleep, arousal and locomotor activity. Orexin A immunoreactivity (orexin A-IR) and prepro-orexin mRNA were measured in the CNS of obese and lean Zucker rats. There were no differences in orexin A-IR or prepro-orexin mRNA levels between obese and lean Zucker rats. The orexins are therefore unlikely to be important in this model of obesity. Levels of orexin A-IR and prepro-orexin mRNA were measured in the CNS of Wistar-Kyoto (WKY) rats, which are hypoactive and have abnormal sleep architecture. Compared to Wistar rats, WKY rats had significantly lower orexin A-IR (with differences of up to 100% in some brain regions) and prepro-orexin mRNA levels. These observations suggest that the sleep and activity phenotype of the WKY strain may be related to orexin deficiency and that this strain may be a useful model of partial orexin deficiency.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.