What is the geographic place of origin of the word "doolally", meaning to have lost one’s mind?

The term “doolally” stems from the nickname given by British soldiers to the British Army transit camp, Deolali (or Devlali), which was located in Maharashtra (near Mumbai), India. The term is a contraction of "Doolally tap", where the latter part is derived from "tapa" ("fever" in Hindustani and "heat" or "torment" in Sanskrit). The whole phrase is best translated as "camp fever".

Established in 1861, the camp remained in use throughout the time of the British Raj. It housed soldiers newly arrived in the country, those awaiting ships to take them to Britain, a military prison, and during the two world wars, it was a prisoner of war camp.

Conditions in the camp were said to be poor especially for those stationed there for long periods, as many were. The term "doolally" became associated with mental illness. Because the soldiers were in transit, there was little for them to do for many months at a time. Men were allowed to spend time in the nearby city of Nashik which offered numerous gin bars and brothels. Venereal disease was common. Malaria, which can affect the brain, was also common in the Deolali area and remained a major issue for the British Army right through the Second World War despite the development of anti-malarial drugs. Suicides in the camp were not uncommon.

Ironically, Deolali, or Devlali, was the setting for the first four series of the British TV sitcom “It Ain't Half Hot Mum”, set in 1945.