Research suggests that there are several long-term side effects associated with long-term cannabis use. There may be risks to brain development especially if use began before the age of 25, which is when the brain is still developing and has not yet reached its full ‘adult state’. An increased risk may exist for the development of mental health problems in long term users. Also, Health Canada estimates that cannabis has an addiction rate of 9 % – albeit low, a risk still exists. There are many other speculated long-term effects, with many on-going studies currently attempting to understand and answer questions through research.