Hallucinogens are a diverse group of drugs that cause an alteration in perception, thought, or mood. A rather heterogeneous group, these compounds have different chemical structures, different mechanisms of action, and different adverse effects.allucinogens are a diverse group of drugs that cause an alteration in perception, thought, or mood. A rather heterogeneous group, these compounds have different chemical structures, different mechanisms of action, and different adverse effects.
Which US President served the shortest term in office? William Henry Harrison, 9th President ,who died in office on April 4, 1841.served the shortest term of any president: March 4 - April 4, 1841. He served 30 days, 12 hours, andâ¦ 30 minutes. He died of pneumonia. William Henry Harrison only held office for 32 days.
Which US President served for the longest term? Franklin D. Roosevelt (32nd President) served for  12 years and 1 month, from March 4, 1933 until his death in office  on April 12, 1945.FDR was elected four times, and the â¦ remaining 39  months of his 4th term were served by his new Vice President, Harry  Truman.ranklin D. Roosevelt was the US President from 1933-1945 and died in office. Roosevelt was elected four times (1932, 1936, 1940, 1944), but died in April, 1945, just four mon â¦ ths into his 4th term.