Volume 3 Issue 2 February, 2013
Cannabis is the most widely used illicit drug in the world. Chinese Emperor Shen Nung first described medicinal use of cannabis in 2700 BC. Cannabis was used in China, India and the Middle East for approximately 8,000 years for medical purposes. It was introduced to Europe in the early 19th century by Napoleon’s army returning from Egypt and later to Britain for medical use by a surgeon who served in India.
Cannabis preparations are obtained from the plant Cannabis sativa which contains the active ingredient Delta-9-tetrahydrocannabinol (THC). Marijuana also known as ganja, grass, pot, weed, etc, consists of dried leaves and flowers of the plant with THC concentration of 1 – 5%. The resin scraped off the plant is known as Hashish (charas) which has THC of 10%. Powder of dried leaves is Bhang which has THC 1-2%. Marijuana & Hashish are smoked and Bhang is taken orally. Bhang is very popular in greater parts of India as it is culturally sanctioned. THC produces its effects by acting on cannabinoid receptor CB1 & CB2.
People who use cannabis experience a “high” characterized by feelings of euphoria, relaxation and perceptual alterations which include time distortion and the intensification of experiences such as eating, watching films, listening to music, engaging in sex, etc. The “high” may be accompanied by infectious laughter, talkativeness, and increased sociability. Cognitive changes include impaired short-term memory. Motor skills, reaction time, motor coordination and many forms of skilled psychomotor activity are impaired.
Psychotic symptoms such as delusions and hallucinations are very rare but usually occur either with high doses of THC or in individuals with a pre-existing vulnerability to psychosis. In cannabis-using cultures, such as India, a “cannabis psychosis” has been reported among heavy users of cannabis. There is consistent evidence that schizophrenia and cannabis use are associated. There is also increasing evidence from longitudinal studies that cannabis use can precipitate schizophrenia in vulnerable individuals or exacerbate its symptoms in those who have already developed the disorder.
Treatment of Cannabis use disorders is mainly symptomatic as there will be psychological dependence more than physical dependence. Irritability, agitation & insomnia in withdrawal period can be treated with benzodiazepines like diazepam or lorazepam. Delusional and hallucinatory experiences will usually disappear within a week’s time after stopping the use of cannabis. But in individuals with cannabis use and schizophrenia, treatment may be prolonged with the use of antipsychotics and rehabilitation care.
Prevention is always better than cure. The ill effects of cannabis should be communicated to the vulnerable population especially the youth. Cannabis use among vulnerable group should be discouraged as the younger age of initiation of cannabis use may increase the risk of developing schizophrenia substantially.
Assistant Professor of Psychiatry,
JNM Medical College, Belgaum
