Narcoanalysis, derived from the Greek word 'narkco', refers to a truth serum test first used in 1922, involving the use of a sodium pentothal injection to induce a semi-conscious state in subjects. This technique is employed in criminal psychology to facilitate interrogation, although its legal admissibility is nuanced, with Indian law requiring voluntary consent and consideration of individual rights. Narcoanalysis has both advantages, such as a high success rate in interrogations, and disadvantages, including risks of extreme lethargy or ineffective results based on individual health conditions.