New findings by a team of British researchers point toward a substantial worsening of existing bipolar disorder symptoms in people who use various forms of the addictive, plant-based drug marijuana\/cannabis. People who consume marijuana or other forms of cannabis may have increased risks for developing serious psychiatric problems, especially when they have genetic or environmental susceptibilities to such problems. In a study published in March 2015 in the journal PLOS One, researchers from two British universities sought to determine how marijuana\/cannabis use impacts the mental health of people affected by either of two mood disorders known as bipolar I disorder and bipolar II disorder. These researchers connected cannabis use to a worsening of both main aspects of bipolar illness. Bipolar Illness Bipolar illnesses get their name because affected individuals periodically swing between two poles of unusually strong and damaging emotion: mania (a state characterized by irritability and heightened energy levels) and depression. The American Psychiatric Association (APA) officially recognizes several forms of these illnesses, including bipolar I disorder and bipolar II disorder. People with bipolar I disorder have a severe type of bipolar illness that includes episodes of fully developed mania and episodes of depression symptoms extreme enough to merit a diagnosis of major depression (the most severe form of depressive illness). APA guidelines mandate that the periods of extreme mania associated with the disorder must last for a week or longer; periods of bipolar I disorder-related depression must last for two weeks or longer. Some people with the disorder experience mixed periods of mania and depression, or cycle through these damaging mental states unusually quickly. People with bipolar II disorder also experience periods of mania and depression. However, their manic episodes don\u2019t reach the severity of the episodes found in people with bipolar I disorder. In addition, people with bipolar II disorder don\u2019t experience mixed episodes of mania and depression. The separate episodes of depression associated with this form of bipolar illness are just as severe as the depression associated with bipolar I disorder. Marijuana\/Cannabis and Mental Health Apart from characteristic symptoms of short-term mind alteration, marijuana\/cannabis use can trigger lasting changes in brain function when consumed at an early age or consumed habitually over time. In addition to altered brain development, memory impairment and diminished intellectual capacity, potential consequences of exposure to the drug include bouts of psychosis (delusions and\/or hallucinations) that strongly resemble schizophrenic mental illness. Risks for such bouts may be rising along with the potency of currently available marijuana\/cannabis. Marijuana\/cannabis consumption may also precipitate the onset of schizophrenia in susceptible individuals. Additional mental health problems linked to cannabis use include medically serious anxiety, medically serious depression and increased odds of contemplating suicide. Marijuana\/Cannabis and Bipolar Illness In the study published in PLOS One, researchers from the United Kingdom\u2019s Lancaster University and University of Manchester used a small-scale study involving 24 people affected by bipolar disorder to help determine the influence that marijuana\/cannabis use has on the manifestations of bipolar illness. All of the study participants had diagnosable cases of bipolar I disorder or bipolar II disorder. In addition, 15 of the participants met the criteria used to diagnose cannabis use disorder (cannabis abuse and\/or cannabis addiction). Most of the participants solely used marijuana, not hashish or hashish oil. After conducting a series of tests over six days, the researchers concluded that people with bipolar I disorder who use marijuana\/cannabis experience a notable increase in their levels of mania-related symptoms, as well as their depression-related symptoms. The researchers made the same conclusions about marijuana\/cannabis consumption in people affected by bipolar II disorder. The study participants experienced a roughly 20 percent uptick in their mania symptoms after using cannabis; their depression symptoms increased by roughly 17 percent. The study\u2019s authors found that people with bipolar I disorder and bipolar II disorder have increased chances of using marijuana\/cannabis when they\u2019re in a relatively good mood (but not a manic mood). They also found that people with either of these illnesses tend to experience significant mood elevation after consuming the drug. However, the authors concluded that the typical bipolar illness-affected individual does not rely on marijuana\/cannabis to self-medicate relatively minor symptoms of his or her condition. They don\u2019t know if bipolar-affected people in the midst of heightened manic or depressive states try to self-medicate with the drug.