The Narcotic Drugs and Psychotropic Substances Act, 1985, often referred to as the NDPS Act, is an Indian legislation relating to the control and regulation of operations relating to narcotic drugs and psychotropic substances.

Narcotic Drugs

These are addictive drugs that reduce pain, induce sleep and alter mood, usually leading to a state of euphoria. Some major narcotic drugs include:

1. Opium: And its derivatives like Morphine and Codeine.
2. Heroin: Derived from the morphine alkaloid found in opium.

Psychotropic Substances

These substances can alter mood, perception, consciousness, and behavior. Some examples include:

1. Barbiturates
2. Benzodiazepines
3. Cannabis: Though it is a narcotic, cannabis is also a psychotropic substance. Products derived from the cannabis plant like charas (hashish), ganja, and any mixture or drink prepared from it are included.
4. LSD (Lysergic acid diethylamide)
5. Amphetamines
6. Methaqualone

The NDPS Act also provides provisions for the controlled cultivation, production, manufacture, possession, sale, import inter-State, export inter-State, use, and possession of these substances.

Key Features of the NDPS Act:

1. Stringent Provisions: The act imposes stringent penalties, which can vary depending on the quantity of the prohibited substance. The Act classifies drug offenses under small quantity, more than small but less than commercial quantity, and commercial quantity, with the penalties becoming increasingly stringent.
2. Rehabilitation of Addicts: The Act provides provisions not just for punitive actions but also for the identification, treatment, education, aftercare, rehabilitation, and social reintegration of addicts.
3. Regulatory Provisions: For medical and scientific use of these substances, the NDPS Act provides provisions where the Central Government can regulate or restrict any operations, including cultivation, production, manufacturing, possession, sale, transport, warehousing, use, etc.
4. International Cooperation: The Act provides a framework to fulfill India’s international obligations under the Single Convention on Narcotic Drugs, 1961, the Convention on Psychotropic Substances, 1971, and the United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances, 1988.
5. Establishment of Authorities: The NDPS Act also provides for the establishment of authorities such as the Narcotics Control Bureau (NCB) to combat drug trafficking and enforce the provisions of the Act.

The NDPS Act is a comprehensive act aimed at controlling and regulating narcotic drugs and psychotropic substances, ensuring their availability for medical and scientific use while preventing their abuse, and combating illicit trafficking. The Act has been amended multiple times, considering the evolving nature of drug use and trafficking to make it more effective.