What long-term damage does cannabis cause?

The regular use of cannabis is known to be associated with an increase in the risk of later developing psychotic illnesses including schizophrenia. If you have a family background of mental illness, you may have an increased risk of developing a psychotic illness using cannabis.

Regular users may find they lack motivation in their day-to-day lives, lose interest in things and lose touch with their friends. Also it is reported that frequent use of cannabis may affect the fertility of men and women.

Like tobacco, cannabis has lots of chemical 'nasties'. These can cause lung disease and possibly cancer with long-term or heavy use. Cannabis can also make asthma worse, and cause wheezing in non-asthma sufferers.

Cannabis is often mixed with tobacco and smoked without a filter so the health risks of tobacco have to be taken in to account too.