How cannabis use affects people with Bipolar Disorder
Science Daily/March 13, 2015
Lancaster University
The first study to examine the use of cannabis in the context of daily life among people with Bipolar Disorder has shown how the drug is linked to increases in both manic and depressive symptoms.
Around 2% of the UK population has Bipolar Disorder, with up to 60% using cannabis at some point in their lives, but research in this area is limited and reasons for high levels of use are unclear.
Dr Elizabeth Tyler of the Spectrum Centre for Mental Health Research at Lancaster University led the study published in PLOS ONE with Professor Steven Jones and colleagues from the University of Manchester, Professor Christine Barrowclough, Nancy Black and Lesley-Anne Carter.
She said: "One theory that is used to explain high levels of drug use is that people use cannabis to self-medicate their symptoms of bipolar disorder. " The study looked at people diagnosed with bipolar disorder but who were not experiencing a depressive or manic episode during the six days the research was carried out.
Each participant completed a paper diary about their emotional state and drug use at several random points daily over a period of week. This enabled people to log their daily experiences in the moment before they forgot how they were feeling.
An individual with experience of bipolar disorder and cannabis use commented: "I do smoke a small amount to lift my mood and make myself slightly manic but it also lifts my mood and switches me into a different mind-set."
"I do not use weed to manage depression as it can make it worse, making me anxious and paranoid."
"I have found though that if I have smoked more excessively it can make me feel depressed for days afterwards."
The study found that the odds of using cannabis increased when individuals were in a good mood. Cannabis use was also associated with an increase in positive mood, manic symptoms and paradoxically an increase in depressive symptoms, but not in the same individuals.
Dr Tyler said: "The findings suggest that cannabis is not being used to self-medicate small changes in symptoms within the context of daily life. However, cannabis use itself may be associated with both positive and negative emotional states. We need to find out whether these relationships play out in the longer term as this may have an impact on a person's course of bipolar disorder."
https://www.sciencedaily.com/releases/2015/03/150313130855.htm
Significant link between cannabis use and onset of mania symptoms
February 10, 2015
Science Daily/University of Warwick
Researchers from the University of Warwick have found evidence to suggest a significant relationship between cannabis use and the onset and exacerbation of mania symptoms.
In a paper published in the Journal of Affective Disorders, mental health researchers from Warwick Medical School carried out a review of scientific literature examining the effect of cannabis use. The literature sampled 2,391 individuals who had experienced mania symptoms.
Mania symptoms are part of bipolar disorder and can include feelings of persistent elation, heightened energy and hyperactivity and a reduced need for sleep. Mania can also make people feel angry and aggressive with extreme symptoms including becoming delusional or hearing voices.
Lead author Dr Steven Marwaha said: "Previously it has been unclear whether cannabis use predates manic episodes. We wanted to answer two questions -- does cannabis use lead to increased occurrence of mania symptoms or manic episodes in individuals with pre-existing bipolar disorder? But also, does cannabis use increase the risk of onset of mania symptoms in those without pre-existing bipolar disorder?"
The researchers looked at a number of previous studies and concluded that cannabis use preceded the onset of mania symptoms.
Dr Marwaha said: "The observed tendency for cannabis use to precede or coincide with rather than follow mania symptoms, and the more specific association between cannabis use and new onset manic symptoms, suggests potential causal influences from cannabis use to the development of mania. It is a significant link."
Dr Marwaha also said the review suggested that cannabis use significantly worsened mania symptoms in people who had previously been diagnosed with bipolar disorder.
He added: "There are limited studies addressing the association of cannabis use and manic symptoms, which suggests this is a relatively neglected clinical issue. However our review suggests that cannabis use is a major clinical problem occurring early in the evolving course of bipolar disorder. More research is needed to consider specific pathways from cannabis use to mania and how these may be effected by genetic vulnerability and environmental risk factors.
"Cannabis is the most prevalent drug used by the under-18s and during this critical period of development services should be especially aware of and responsive to the problems that cannabis use can cause for adolescent populations.
https://www.sciencedaily.com/releases/2015/02/150210160101.htm