However, "liking" or consummatory pleasure, is intact in people with schizophrenia, as they report experiencing the same degree of positive affect when presented with rewarding stimuli. Neuroimaging studies support this behavioral observation, as most studies report intact responses in the reward system (i.e. ventral striatum, VTA) to simple rewards. However, studies on monetary rewards sometimes report reduced responsiveness. More consistent reductions are observed with regard to emotional response during reward anticipation, which is reflected in a reduced responsiveness of both cortical and subcortical components of the reward system. Schizophrenia is associated with reduced positive prediction errors (a normal pattern of response to an unexpected reward), which a few studies have demonstrated to be correlated with negative symptoms. People with schizophrenia demonstrate impairment in reinforcement learnings tasks only when the task requires explicit learning, or is sufficiently complex. Implicit reinforcement learning, on the other hand, is relatively intact. These deficits may be related to dysfunction in the ACC, OFC and dlPFC leading to abnormal representation of reward and goals. Substance-related disorders
Anhedonia is common in people who are dependent upon any one or more of a wide variety of drugs, including alcohol, opioids, and nicotine. Although anhedonia becomes less severe over time, it is a significant predictor of relapse. Post-traumatic stress disorder
While PTSD is associated with reduced motivation, part of the anticipatory "wanting", it is also associated with elevated sensation seeking, and no deficits in physiological arousal, or self reported pleasure to positive stimuli.
In February 2007, the American Heart Association warned that with respect to "patients with a prior history of or at high risk for cardiovascular disease... use of COX-2 inhibitors for pain relief should be limited to patients for whom there are no appropriate alternatives, and then, only in the lowest dose and for the shortest duration necessary. "In 2005, a study published in the Annals of Internal Medicine found that cardiovascular effects of COX-2 inhibitors differ, depending on the drug. Other COX-2-selective inhibitors, such as rofecoxib, have significantly higher myocardial infarction rates than celecoxib. In April 2005, after an extensive review of data, the FDA concluded it was likely "that there is a class effect for increased CV risk for all NSAIDs". In a 2006 meta-analysis of randomized control studies, the cerebrovascular events associated with COX-2 inhibitors were examined, but no significant risks were found when compared to nonselective NSAIDs or placebos. Drug interactions
Celecoxib is predominantly metabolized by cytochrome P450 2C9. Caution must be exercised with concomitant use of 2C9 inhibitors, such as fluconazole, which can greatly elevate celecoxib serum levels. If used concomitantly with lithium, celecoxib increases lithium plasma levels. If used concomitantly with warfarin, celecoxib may result in increased risk of bleeding complications. The risk of bleeding and gastric ulcers also increase further when SSRIs are used in combination with celecoxib. The drug may increase the risk of kidney failure with angiotensin-converting enzyme-inhibitors, such as lisinopril, and diuretics, such as hydrochlorothiazide.