Recreational marijuana use associated with increased impulsivity and hostility in daily life
February 17, 2015
Despite high levels of marijuana use in the United States, little is known about the effects of recreational marijuana use on daily life. Most studies exploring this issue have either been conducted in a laboratory setting or have relied on retrospective reports of mood and use, which can be unreliable. One method to better capture information about experiences in real-life settings is Ecological Momentary Assessment (EMA), where participants answer specific questions as they go about their typical, daily routines. In a recent 14-day study using a smartphone-based EMA, recreational marijuana users (average use of 4.5 days over the past 30 days) who also drank alcohol at least once per week answered questions each day regarding their alcohol consumption, marijuana use, and number of cigarettes or cigars smoked. Participants also answered questions to assess hostility following any interaction with another person that lasted longer than five minutes. In addition, end-of-day surveys were completed to measure impulsivity. For each subject, days of marijuana use and non-use were compared to look for changes in impulsivity and hostility. Results showed that marijuana use was correlated with increased impulsivity on the day of use and the following day. Participants also reported higher hostility ratings – for both themselves and their perception of others – on the day they used marijuana. This effect did not last into the next day and appeared to lessen as the study progressed. Results were not impacted by other variables measured, such as alcohol or nicotine use.
While this research couldn’t determine whether marijuana caused these effects – or if increased impulsivity and/or hostility were stressors that led to marijuana use – these results highlight the need for further research to determine how marijuana impacts the daily experiences of recreational users.