There are several long-term effects of cannabis abuse.
Risk of mental illness
The first and arguably the most concerning is that young people, adolescents, who smoke cannabis on a regular basis have a much higher risk of developing a severe mental illness, such as schizophrenia. And this association is increasingly recognised over the last 10 to 20 years. And it is due to the fact that cannabis, today, is much stronger than it used to be. And secondly, cannabis is very taxing on a developing brain. So that’s one very concerning result of cannabis abuse.
A pathway to other drugs
The second is, probably, those people who severely abuse cannabis have a greater likelihood of going on and using other more severe drugs, such as amphetamines, opiates, and stimulants. So cannabis is probably a pathway drug to other drugs of addiction.
Loss of motivation
Thirdly, chronic cannabis users will develop what’s called an a motivational syndrome. So the more they smoke dope, the more they start to lose their drive, lose their energy, lose their desire to conduct themselves in a normal fashion.
Impact on relationships
Fourthly, chronic cannabis use has its impacts on relationships, be it family, interpersonal relationships, such as girlfriends or boyfriends. It is a drug of addiction, and used excessively, does, like all drugs, start to impact relationships.
Low mood and depression
And then finally, chronic cannabis use does actually contribute to increased risk of low mood and depression.
So in summary, intermittent use of cannabis probably is relatively harmless, but chronic, persistent cannabis use impacts all elements of one life, both biologically, psychologically, and socially.