In 1962 Meehl furthered Rados theory through the introduction of the concept of schizotaxia, a genetically driven neural integrative defect thought to give rise to the personality type of schizotypy. Loren and Jean Chapman further distinguished between two types of anhedonia: physical anhedonia, or a deficit in the ability to experience physical pleasure, and social, or a deficit in the ability to experience interpersonal pleasure.Recent research suggests that social anhedonia may represent a prodrome of psychotic disorders. First-degree relatives of individuals with schizophrenia show elevated levels of social anhedonia, higher baseline scores of social anhedonia are associated with later development of schizophrenia. These findings provide support for the conjecture that it represents a genetic risk marker for schizophrenia-spectrum disorders. Additionally, elevated levels of social anhedonia in patients with schizophrenia have been linked to poorer social functioning. Socially anhedonic individuals perform worse on a number of neuropsychological tests than non-anhedonic participants, and show similar physiological abnormalities seen in patients with schizophrenia. Comorbidity
Anhedonia is present in several forms of psychopathology. Depression
Social anhedonia is observed in both depression and schizophrenia. However, social anhedonia is a state related to the depressive episode and the other is trait related to the personality construct associated with schizophrenia. These individuals both tend to score highly on self-report measures of social anhedonia.
Crotamiton is a drug that is used both as a scabicidal (for treating scabies) and as a general antipruritic (anti-itching drug). It is a prescription, lotion-based medicine that is applied to the whole body to get rid of the scabies parasite that burrows under the skin and causes itching. Use
For treating scabies, crotamiton should be applied to the whole body rather than a localized area. It is applied two or three times, with a 24-hour delay between applications, and the patient is asked to take a shower no sooner than after 48 hours. For children under 3 years, it is applied once daily. It can also be used to treat itching stemming from other causes, e.g. insect bites, in which case it is applied to the itching areas only, and repeated if necessary after 4 to 8 hours. Use near the eyes, or breaks in the skin, should be avoided. Pharmacology
Crotamiton is toxic to the scabies mite. It probably acts as a general antipruritic by inhibition of TRPV4, a sensory ion channel that is expressed in the skin and primary sensory neurons. Pharmacokinetics
After topical application, crotamiton is absorbed systemically. It has an elimination half-life of 30.9 hours and 4.8-8.8% is excreted in the urine. Side effects
The most common side effect of crotamiton is skin irritation. Trade name
Crotamiton is marketed under the trade names Eurax, which is manufactured by Ranbaxy Laboratories in the United States, and GlaxoSmithKline in the United Kingdom, and Euracin, which is manufactured by Green Cross in South Korea.