• Cannabis: The plants used for making marijuana

• Plant features

Annual

Dioecious

Flowering

Wind-pollinated

Marijuana has become the most common and the least expensive drug for recreational use in the modern world.

Which country has the biggest number of people who

take in marijuana?

Australia According to a survey in 2009, 15% people in

Australia between ages from 15 to 64 have the experience of taking in marijuana.

Street names:

Grass, joints, pot, reefer, weed

-spirit: moral degration

-mood： anxious—euphoria—enchanted

-sense： colorful; sensitive to sound; time slower; things bigger

-movement: torpor; unbalanced

- Caused by tetrahydrocannabinol (THC)-both psychological and physiological effects -biochemical effect /short-term effect/long-term effect

•Biochemical ： heart rate increase; decrease eye pressure; cancer; bronchitis

• Short-term: euphoria; anxiety

• Long-term ： schizophrenia; bipolar disorders; and major depression

• The most prevalent psychoactive substances in cannabis are cannabinoids, including delta-9-tetrahydrocannabinol (Δ9-THC, commonly called simply THCTHC) and tetrahydrocannabivarin (THCVTHCV), --Cannabis cofactor compounds -- lowering body temperature, modulating immune functioning, and cell protection.

--THC and cannabidiol are also neuroprotective antioxidants.

--THC and endogenous anandamide additionally interact with glycine receptors.

• Biochemical mechanism in the brain--the use of cannabis affects the brain in the same manner as a naturally occurring brain chemical.

--The CB1 receptor -- in the brain--mediates the psychological effects of THC. --The CB2 receptor -- on cells of the immune system.

--Cannabinoids likely have a role in the brain’s control of movement and memory and natural pain modulation.-- affect pain transmission and interact with the brain‘s endogenous opioid system （ important pathway for medical treatment of pain ）

• Psychoactive Effect--As the chemical THC reaches parts of the brain, it attaches to cannabinoid receptors.

--Usually the receptors are blocked by anandamide produced at low rates by the body, but the large percent of THC increases the blocking of the receptors, and allows dopamine to flow freely.

--As dopamine reaches the receptors, the body experiences a heightened focus, and a greater level of perception

--resulting in extremely elevated emotions and feelings.

• Neurological Effect--The areas of the brain with abundant cannabinoid receptors are consistent with the behavioral effects produced by cannabinoids.

--Cannabinoids, depending on the dose, inhibit the transmission of neural signals through the basal ganglia and cerebellum.

--disruption of short-term memory formation-- Cannabinoids inhibit the release of several neurotransmitters in the hippocampus --decrease in neuronal activity in that region

1 ） Neurological disorders

Unconsciousness Anxiety Melancholy

2 ） damage our memory and behavior cause

The function of brain, attention, calculation ability and sense will decrease or loss.

3)Effect the immune system

can damage the body's immune system, resulting in cellular and humoral immune function, vulnerable to viruses, bacterial infection

4) Effects of movement coordination

damage muscle movement coordination functions, resulting in complex standing balance disorders

--treating depression

• Cannabis used medically has several beneficial effects.

--amelioration of nausea and vomiting

--stimulation of hunger in chemotherapy and AIDS patients

--lowering eye pressure (for treating glaucoma)

--Painkiller

--Relaxing muscles (for treating multiple sclerosis)

• Taking some medicine, like Methadoni Hydrochloridum.

• Setting one’s mind at rest.

• Taking part in some specific exercises.

• Getting professional psychological doctors’ help.

• Abrupt stop can cause people excited, unrest, decreased appetite, insomnia, hypothermia and even shivering, fever, tremor. These symptoms will disappear in 4 ~ 5 days. Rehabilitation needs a long process.