Teenage cannabis use may increases a person’s risk of suffering from bipolar disorder in later life, new research suggests.
People who used cannabis at least two-to-three times a week at 17 years old are more likely to experience hypomania in their earlier 20s, according to the first study of its kind.
Hypomania is defined as an elevated mood alongside irritability or an inflated ego, an unrealistic sense of superiority, frenzied speech and a reduced need for sleep.
Such symptoms frequently occur in bipolar-disorder sufferers.
Lead author Dr Steven Marwaha from Warwick Medical School, said: ‘Adolescent cannabis use may be an independent risk factor for future hypomania, and the nature of the association suggests a potential causal link.’
Cannabis is the most commonly-used drug in the UK, with 6.5 per cent of people aged between 16 and 59 taking it in the past year, which makes up around 2.1 million individuals.
Teenage cannabis use may increases a person’s later risk of suffering from bipolar disorder
How the research was carried out
The researchers analysed 3,370 women from a previous study.
The study’s participants’ cannabis use at 17 years old was assessed by asking if they took the drug and, if so, how frequently over a 12-month period.
At 22-to-23 years old, the participants completed a questionnaire that investigated their lifetime experience of maniac symptoms, including their emotions, thoughts and behaviour while in a ‘high’ state.
Teenage cannabis use may cause bipolar in later life
Results reveal using cannabis at least two-to-three times a week at 17 years old increase a person’s later risk of suffering hypomania.
Hypomania is defined as elevated mood alongside irritability or an inflated ego, an unrealistic sense of superiority, a reduced need for sleep and frenzied speech.
Such symptoms frequently occur in bipolar disorder sufferers.
Dr Marwaha said: ‘Cannabis use in young people is common and associated with psychiatric disorders. However, the prospective link between cannabis use and bipolar disorder symptoms has rarely been investigated.
‘Adolescent cannabis use may be an independent risk factor for future hypomania, and the nature of the association suggests a potential causal link.
‘As such it might be a useful target for indicated prevention of hypomania.’
The findings were published in the journal Schizophrenia Bulletin.