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Mad Hatter’s disease

a condition caused by chronic mercury poisoning and characterized by changes in mental status, emotional disturbance, gastrointestinal disturbances, and weakness or partial paralysis of the legs. The condition may also cause psychosis, behavioral changes, erethism, and several other symptoms. The name derives from the prevalence of this condition among hatters whose occupation, until the mid-20th century, exposed them to vapors from the mercury used to treat felt for hats. Also called Mad Hatter’s syndrome.

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Psychology term of the day

January 31st 2025

Kretschmer typology

Kretschmer typology

a controversial classification of individuals based on a “clear biological affinity” between specific physiques and specific personality tendencies. According to this classification, the short, stocky pyknic type tends to be jovial and subject to mood swings; the frail asthenic type is likely to be introversive and sensitive; the muscular athletic type is usually energetic and aggressive; and the disproportioned dysplastic type presents a combination of traits but tends toward the asthenic. These tendencies were attributed to endocrine secretions. [formulated in the 1920s by German psychiatrist Ernst Kretschmer (1888–1964)]