Bipolar disorder risk linked to cannabis disrupting daily routines

New research published in Journal of Affective Disorders indicates that for young adults at risk for bipolar spectrum disorders, cannabis consumption is more likely to interfere with daily responsibilities like work and school rather than strictly leading to more frequent drug use. The study also explores how specific positive emotional processes, such as an intense drive to achieve happiness, relate to different patterns of cannabis consumption and difficulty quitting.

Substance use research frequently examines how drugs like cannabis interact with negative emotional states, such as anxiety and depression. Less attention has been directed toward the role of positive emotions. Positive emotions are generally associated with basic well-being and achieving goals, but they can sometimes become dysregulated. Conditions like bipolar spectrum disorders are characterized by disruptions in these positive emotional systems.

Cannabis is the most widely used illicit substance globally, and its consumption has risen rapidly over the past decade as legalization policies shift. While cannabis has known medical applications, heavy recreational use is associated with mental health risks. These risks include impaired driving, an increased likelihood of hospitalizations, and the development of substance use disorders. Given that young adulthood is a time of increased physical access to substances, understanding how cannabis interacts with mental health during this specific life stage is an urgent public health priority.

Bipolar spectrum disorders are psychiatric conditions that involve extreme shifts in mood, energy, and activity levels. People with these conditions experience depressive episodes marked by deep sadness and fatigue, which occur alongside contrasting episodes of mania or hypomania. Mania involves an abnormally elevated mood, high energy, impulsivity, and a decreased need for sleep. Hypomania is a milder form of mania that features similar energetic elevations but does not typically cause severe functional impairment.

Individuals with or at risk for these disorders often experience more intense positive emotions in response to everyday events. They also tend to show a heightened response to rewards and may struggle to manage or regulate intense feelings of happiness. Bipolar mood disorders and cannabis use frequently occur together in psychiatric settings. This combination is often linked to an earlier onset of psychiatric symptoms and a worsening of clinical outcomes.

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University of Colorado Boulder psychology researcher Luiza Rosa and colleagues wanted to understand how cannabis use relates to both the risk for bipolar disorders and the positive emotional processes that underlie them. The team focused on emerging adults between the ages of 18 and 25. This developmental stage is known for heightened emotional reactivity, increased independence, and greater risk-taking behavior. It is also a peak period for the onset of mood disorders and regular substance use.

The researchers recruited 968 college students from nine universities across North America. To participate, all students had to report using cannabis at least once in their lifetime. The participants completed a series of remote surveys that assessed their patterns of cannabis consumption over the previous 90 days. When running their statistical models, the researchers adjusted the data to account for the age and sex of the participants, as well as the specific university they attended.

The surveys evaluated three specific elements of problematic cannabis habits. These included the frequency of use, how much the drug interfered with school, work, or home life, and how difficult the participants thought it would be to stop using entirely. The researchers also measured the participants’ underlying risk for developing a bipolar spectrum disorder using a specialized personality questionnaire.

To gauge positive emotional processes, the team asked participants to rate how often and how intensely they recently experienced positive emotions. They also measured reward responsiveness, or how excited and energized the students felt when they obtained something they wanted. A third measure assessed positive emotion valuation. This concept refers to how much a person strives to feel happy and how much they worry about their own happiness levels.

In behavioral science, there are competing theories about how reward responsiveness relates to drug use. The reward hypersensitivity perspective suggests that people who are exceptionally sensitive to rewards are more vulnerable to seeking out the immediate highs provided by substances. In contrast, the hyposensitivity perspective proposes that people with blunted reward systems might use drugs to cope with feelings of numbness or mild depression. The current study aimed to gather data that might clarify how these emotional reward systems function specifically in relation to cannabis.

The results revealed that having a higher risk for a bipolar spectrum disorder was associated with greater cannabis-related interference in daily life. This means that individuals predisposed to intense mood shifts experienced more disruptions to their work or school obligations due to cannabis. The risk for bipolar spectrum disorders was not associated with a higher frequency of cannabis use or greater difficulty quitting the drug.

The researchers interpret this as a sign that for people at risk of bipolar disorders, the primary issue is how the substance impedes daily functioning, rather than the raw amount consumed. However, when the researchers factored in the participants’ current, short-term mood symptoms, the association between underlying bipolar risk and daily interference no longer held up. Instead, current feelings of depression were specifically linked to greater cannabis interference.

The team also found distinct relationships between cannabis consumption and specific emotional tendencies. Experiencing high levels of positive emotion on a daily basis was linked to less frequent cannabis use. Those who reported intense daily positive emotions also experienced less cannabis-related interference in their lives and reported less difficulty stopping the drug. The researchers suggest that natural positive emotions might serve as a protective factor against severe cannabis issues.

A different pattern emerged for individuals who place a very high value on being happy. People who are highly concerned about achieving and maintaining happiness used cannabis more frequently and reported greater difficulty stopping. The researchers propose that an intense preoccupation with feeling happy might drive people to use cannabis repeatedly as a quick way to regulate their mood. If a person views their baseline emotional state as inadequate, they may turn to psychoactive compounds to artificially synthesize the joy they feel they are missing.

Some initial calculations hinted that a lower internal response to real-world rewards might be linked to more cannabis interference. However, those results were not statistically significant once the researchers controlled for alcohol consumption. This suggests that some emotional disruptions are more closely tied to alcohol than to cannabis directly, failing to firmly support the hypersensitivity or hyposensitivity reward models for marijuana.

The study relies on a cross-sectional design, which means the researchers collected all the data at a single point in time. Because of this, the researchers cannot determine cause and effect. It is not possible to say whether an intense drive to be happy causes someone to use more cannabis, or if frequent cannabis use alters how a person prioritizes happiness.

The researchers note that their sample mostly consisted of infrequent cannabis users, with the most common usage rate being less than once a month. The findings might differ in a sample of people diagnosed with severe substance addictions. Additionally, the data relies on self-reported surveys rather than objective clinical interviews, which could introduce bias entirely based on human memory.

Future research will need to follow individuals over longer periods of time to track how specific positive emotional processes develop alongside cannabis habits. Experimental studies could help identify whether cannabis use directly alters a person’s risk for bipolar mood episodes in an isolated setting. By examining both positive and negative emotional networks, researchers hope to better treat substance use issues in people with mood disorders.

The study, “The highs and lows: Cannabis use and positive valence bipolar mood and emotion processes in emerging adults,” was authored by Luiza Rosa, Gerald Young, Stevi G. Ibonie, Joelle LeMoult, Iris B. Mauss, Lauren B. Alloy, Jessica L. Borelli, Sarah R. Holley, Ellen Jopling, Daniel P. Moriarity, Robin Nusslock, Gregory Strauss, Cynthia M. Villanueva, Lauren M. Weinstock, L. Cinnamon Bidwell, and June Gruber.