Traumatic brain injury, depression and cannabis use--assessing their effects on a cognitive performance

Patient RB is presented as a demonstration of the need for a more thorough understanding of the interactions of patient variables. RB had a history of traumatic brain injury along with current mood disorder and cannabis use. It was unclear initially whether or not his cognitive impairment was a permanent result of the brain injury, or a temporary effect of his mood and/or drug use. The literature offers few guidelines or precedents for understanding such complex cases or suggesting at which level it may be most appropriate to intervene. The impact of cannabis use in this individual appeared to have a detrimental effect on his mood. Treating RB's mood disorder resulted in larger cognitive gains than would have been anticipated in the literature. Specific neuropsychological tests are identified as being particularly sensitive to the cognitive changes in mood disorders.