NS2359 is a potent reuptake blocker of noradrenalin, dopamine, and serotonin. The aim of the study was to investigate the efficacy, safety and cognitive function of NS2359 in adults with a DSM IV diagnosis of ADHD.
The study was a multi-centre, double-blind, randomized placebo-controlled, parallel group design in outpatient adults (18–55 years) testing 0.5 mg NS2359 vs. placebo for 8 weeks. Multiple assessments including computerized neuropsychological evaluation were performed.
There was no significant difference between NS2359 (n = 63) versus placebo (n = 63) on the primary outcome measure reduction in investigator rated ADHD-RS total score (7.8 versus 6.4; p < 0.45). However, in subjects with the inattentive subtype, there were significantly more responders in the NS2359 group compared to placebo (41% versus 7%; p < 0.01). For all secondary variables (ADHD-RS patient rated; The Conners Adult ADHD Scale; The Brown Adult Scale, and CGI-improvement scale) there were no significant differences between the two groups; however, in the inattentive subgroup, the response to treatment was significantly larger than to placebo. NS2359 improved composite factor scores of attention, episodic- and working memory. No serious adverse events were reported with insomnia, headaches and loss of appetite most commonly reported as side effects.
No overall effect of NS2359 was found on overall symptoms of ADHD. There was also a modest signal of improvement in the inattentive adults with ADHD and cognition warranting further exploration using differing doses.