I wonder then what the effect of cannabis is on the motivation&#x2F;drive of someone with ADHD. Does the ADHD subject have a very weak frontostriatal circuit to begin with so that low dopamine levels only make something weak weaker (and therefore not having as profound outward effect as making a strong frontostriatal circuit weak).<p>Or do the low dopamine levels and impaired circuit compound each other, resulting in a larger-than-normal decline in motiviation.