Neurocognition of females with substance use disorder and comorbid personality disorder: divergence in subjective and objective cognition

At least one in four patients with substance use disorder (SUD) meet criteria for personality disorder and overlapping neurocognitive deficits may reflect shared neurobiological mechanisms. We studied neurocognition in females attending residential SUD treatment by comparing SUD with (n = 20) or without (n = 30) comorbid personality disorder. Neuropsychological testing included working memory, inhibition, shifting, verbal fluency, design fluency, psychomotor speed, immediate and delayed verbal memory, processing speed, premorbid functioning, cognitive screening, and self-reported executive function. As expected, whole-sample deficits included working memory (d = –.91), self-reported executive function (d = –.87), processing speed (d = –.40), delayed verbal memory recall (d = –.39), premorbid functioning (d = –.51), and cognitive screening performance (d = –.61). Importantly, the comorbid personality disorder group showed greater self-reported executive dysfunction (d = –.67) and poorer shifting performance (d = –.65). However, they also evidenced better working memory (d =.84), immediate (d =.95) and delayed (d =.83) verbal memory, premorbid functioning (d =.90), and cognitive screening performance (d =.77). Overall executive dysfunction deficits were concordant with those observed in previous SUD studies. Surprisingly, comorbid personality disorder was associated with a pattern indicating poorer subjective (self-report) but better objective performance on a number of tasks, apart from shifting deficits that may relate to emotion dysregulation. Subjective emotional dysfunction may influence the cognitive deficits observed in the personality disorder group.