Cognitive dysphoria (semantically the opposite of euphoria) is medically recognized as a cognitive and emotional state in which a person experiences intense feelings of discomfort and unhappiness. These feelings can vary in their intensity depending on the dosage consumed and the user's susceptibility to mental instability. Although dysphoria is an effect,  the term is also used colloquially to define an intense state of general melancholic unhappiness combined with an overwhelming sense of discomfort and malaise. Cognitive dysphoria is often accompanied by other coinciding effects such as anxiety and depression.  It is most commonly induced under the influence of moderate dosages of deliriant compounds, such as DPH and datura. However, it can also occur during a stimulant offset and during the withdrawal symptoms of almost any substance.
- Key DSM-IV Mental Status Exam Phrases | http://bipolar.about.com/cs/faqs/f/faq_dysphoria.htm
- Medical dictionary Dysphoria | http://medical-dictionary.thefreedictionary.com/dysphoria