RESULTS Modafinil appears to improve reaction time ( P ≤ 0.04 ) , logical reasoning ( P ≤ 0.05 ) and problem-solving .
Across all three types of prescription stimulants , research shows improved attention with lack of consensus on whether these improvements are limited to simple versus complex tasks in varying youth population s. CONCLUSIONS The heterogeneity of the non-attention deficit hyperactivity disorder youth population , the variation in cognitive task characteristics and lack of replication of studies makes assessing the potential global neurocognitive benefits of stimulants among non-attention deficit hyperactivity disorder youth difficult ; however , some youth may derive benefit in specific cognitive domains
BACKGROUND AND AIMS Increasing prescription stimulant abuse among youth without diagnoses of attention deficit hyperactivity disorder ( ADHD ) is of concern .
The most frequently cited motive for abuse is improved academic achievement via neurocognitive enhancement .
Our aim in review ing the literature was to identify neurocognitive effects of prescription stimulants in non-ADHD youth .
Tryptophan depletion impairs stimulus-reward learning while methylphenidate disrupts attentional control in healthy young adults: implications for the monoaminergic basis of impulsive behaviour
Abstract Rationale : Altered serotonergic and dopaminergic function have been widely implicated in behavioural disorders associated with impulsivity and risk-taking . However , little research has addressed the specific cognitive consequences of changed monoaminergic function that might contribute to the production of impulsive behaviour . Objectives and methods : We compared the effects of rapid plasma tryptophan depletion , acute doses of the mixed indirect catecholamine agonist , methylpheni date ( 40 mg ) , and acute doses of the α1/α2 agonist , clonidine ( 1.5 µg/kg ) , on aspects of visual discrimination learning involving either acquisition of altered stimulus-reward associations ( i.e. updating the affective valence of exteroceptive stimuli ) or the control of attention towards relevant as opposed to irrelevant stimulus dimensions . Results : Relative to subjects who received placebo , subjects with reduced tryptophan exhibited a deficit in the ability to learn changed stimulus-reward associations , but were still able to shift an acquired attentional set away from a now-irrelevant stimulus dimension towards a newly relevant dimension . By contrast , subjects who received methylpheni date were able to learn effectively about changing stimulus-reward associations , but showed an enhanced ability to shift an attentional bias , in combination with slowed response times .  Subjects who received clonidine showed neither of these changes . Conclusions : These results suggest that reduction in central serotonin leads to altered neuromodulation of the cortical and subcortical regions ( e.g. orbitofrontal cortex , striatum and anterior temporal structures ) that mediate important aspects of associative learning whereby exteroceptive stimuli acquire altered incentive motivational value . On the other h and , facilitation of catecholamine neurotransmitters may disrupt the allocation of attention between relevant and irrelevant features of the environment , perhaps through altered modulation of the dorsolateral prefrontal cortex . The implication s of these results for underst and ing the differential neuromodulation of cognitive functions are discussed
RESULTS Modafinil appears to improve reaction time ( P ≤ 0.04 ) , logical reasoning ( P ≤ 0.05 ) and problem-solving .
Across all three types of prescription stimulants , research shows improved attention with lack of consensus on whether these improvements are limited to simple versus complex tasks in varying youth population s. CONCLUSIONS The heterogeneity of the non-attention deficit hyperactivity disorder youth population , the variation in cognitive task characteristics and lack of replication of studies makes assessing the potential global neurocognitive benefits of stimulants among non-attention deficit hyperactivity disorder youth difficult ; however , some youth may derive benefit in specific cognitive domains
BACKGROUND AND AIMS Increasing prescription stimulant abuse among youth without diagnoses of attention deficit hyperactivity disorder ( ADHD ) is of concern .
The most frequently cited motive for abuse is improved academic achievement via neurocognitive enhancement .
Our aim in review ing the literature was to identify neurocognitive effects of prescription stimulants in non-ADHD youth .