Impaired spatial working memory in adults with attention-deficit/hyperactivity disorder: comparisons with performance in adults with borderline personality disorder and in control subjects.

Objective:  This study investigated a previous claim that working memory may be ‘particularly impaired’ in adult attention-deficit/hyperactivity disorder (ADHD), compared with other psychiatric disorders which affect frontal lobe-mediated executive functions. Method:  Performance on spatial working memory (SWM) and two additional tasks were investigated for adult patients selected on the basis of DSM-IV ADHD (n = 19), adult patients selected on the basis of borderline personality disorder (BPD) (n = 19), and non-clinical control subjects (n = 19). Groups were matched for age, verbal IQ and gender. Results:  Analysis of variance showed that the ADHD group had significant impairment of SWM performance relative to the non-clinical controls. Although there was a trend towards impairment in the BPD group relative to non-clinical controls, this did not reach significance. Conclusion:  The results are consistent with the claim that aspects of working memory are ‘particularly impaired’ in adult ADHD. Also, the BPD group had a longer deliberation time for one of the additional tasks, compared with the ADHD group, which indicated that the patient groups may have different patterns of neuropsychological impairments.