Dependence on cannabis means that the person needs to use cannabis just to feel ‘normal’ (neuroadaptation).

Signs & symptoms include:

• Activates cannabinoid receptors. 
• Also increases dopamine activity in the mesolimbic pathway.

• Smoking cannabis delivers THC rapidly to the blood and brain (Todd et al, 2002).
• It reaches its peak in approximately 10 to 20 minutes and its effects last for around 2 hours. 
• When taken orally or ingested, the route of absorption is slower and more variable and the effects are often less pronounced (Todd et al, 2002). 
• The psychoactive effects of THC last only several hours, however, it can be detected in blood after 20 hours and it accumulates in the tissues of the kidneys, liver, spleen and testes. 

• Marijuana is smoked in hand-rolled cigarettes called joints, or in a pipe or bong
• Hashish is usually added to tobacco and smoked, or baked and eaten in foods such as hash cookies and cakes
• Hash oil is usually spread on the tip or paper of a cigarette and then smoked
• Cannabis and hash can also be smoked in vaporisers that heat the cannabis to temperatures that release its active ingredients while minimising the toxins associated with burning

Onset

There is no risk of overdose or death from cannabis use as there are few cannabis receptors in the brainstem which control vital functions (Denning et al, 2004).

If you take a large amount of cannabis, you may:

• feel confused
• vomit
• be restless
• experience change in your perception of time, sound, sight, touch and distance
• feel excited
• see or hear things which are not there (hallucinations)
• feel anxious or panicky
• ‘black out’
• feel distant or separate from reality

• Euphoria
• Mild enhancement of senses (smell, taste, hearing)
• Subtle changes in thought and expression
• Talkativeness
• Drowsiness
• Increased appreciation of music
• Mild closed-eye visuals
• Anaesthesia
• Decreased nausea
• Increased appetite
• More pronounced visual hallucinations
• Altered sense of time (Campbell 2001)

• memory loss
• confusion and difficulty thinking clearly
• Lethargy and lack of motivation
• headaches
• drowsiness and sleepiness
• difficulty sleeping and disturbing sleep
• nausea
• personality change and changes in emotional response
• anxiety
• irritability
• paranoia and aggression
• depression and lack of motivation
• muscle weakness
• fatigue
• skin rashes
• weight gain
• menstrual irregularities

• Depression
• Confusion
• Feelings of isolation
• Double or blurred vision
• Dry mouth
• Slurred speech or stuttering
• Fatigue
• Increased risk of accidents and falling over (especially for older people)
• Memory loss
• Impaired thinking
• Headache
• Drowsiness and sleepiness
• Vertigo
• Muscle tremors
• Impaired motor coordination
• Nausea and vomiting
• Loss of appetite
• Diarrhoea and constipation