Long term effects of marijuana

The main issue with long term use of marijuana is that of addiction. Physical dependency is not a problem per se but psychological dependency is a real problem which needs to be addressed.

The longer someone uses marijuana the harder they will find it to give up. Long term use leads to a state in which the user is unwilling or unable to stop due to their reliance on the drug plus withdrawal symptoms.

Many people in that situation report that they need marijuana to function on a day to day level. They exist in a constant haze and find it difficult to perform even the simplest tasks.

Apart from addiction, other long term effects include:

• Lack of drive and motivation
• Poor short term memory
• Difficulty in processing complex information
• Inability to focus
• Lack of energy
• Risk of respiratory infections especially in asthma sufferers
• Increased risk of lung, head and throat cancers (in marijuana smokers).
• Reduced sperm count and fertility (men)
• Irregular periods (women)
• Impaired immune system which means an increased risk of infections.

The mental and physical effects are discussed as separate sections, and in more detail within this guide.

Find out more about the health risks in our physical effects of marijuana section.

Find out more about the mental risks in our psychological effects of marijuana section.

A major concern is whether using marijuana leads to other drugs such as heroin and cocaine. There are cases where people who misuse heroin and cocaine also use marijuana but many users of marijuana do not automatically turn to hard drugs.

In other words, using marijuana does not mean that you will go on to try other drugs such as ecstasy, heroin and cocaine.

Many of the long term effects of marijuana are still unknown but evidence points to potential health risks from doing so. One of these is cancer which is a particular risk for people who add marijuana to tobacco and smoke this cigarette as a ‘joint’.

It is easy to assume that as marijuana is a plant that it is relatively harmless but unfortunately, that is not the case. Marijuana can be mixed with other substances to increase its bulk and the profit for the dealer, and these can have side effects.

An example of this is where cannabis resin is ‘cut’with substances such as turpentine, glass, and boot polish and animal faeces. These substances are ingested along with the resin but no-one is quite sure what the long term effects are likely to be.