Neurocognitive profiles in treatment-resistant bipolar I and bipolar II disorder depression
1 Moodnet Research Group, Psychiatric Division, Haukeland University Hospital, Bergen, Norway
2 Department of Clinical Medicine, Section of Psychiatry, University of Bergen, Bergen, Norway
3 Moodnet Research Group, Psychiatric Division, Stavanger University Hospital, Stavanger, Norway
4 Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway
5 Institute of Clinical Medicine, University of Oslo, Oslo, Norway
6 Centre for Clinical Research, Haukeland University Hospital, Bergen, Norway
7 Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway
8 Department of Biological and Medical Psychology, University of Bergen, Bergen, Norway
9 Department of Psychosomatic Medicine, Oslo University Hospital, Rikshospitalet, Oslo, Norway
10 Department of Neuroscience, Faculty of Medicine, NTNU, Trondheim, Norway
11 Division of Psychiatry, St. Olav’s University Hospital, Trondheim, Norway
12 Department of Psychology, University of Oslo, Oslo, Norway
BMC Psychiatry 2013, 13:105 doi:10.1186/1471-244X-13-105Published: 4 April 2013
The literature on the neuropsychological profiles in Bipolar disorder (BD) depression is sparse. The aims of the study were to assess the neurocognitive profiles in treatment-resistant, acutely admitted BD depression inpatients, to compare the neurocognitive functioning in patients with BD I and II, and to identify the demographic and clinical illness characteristics associated with cognitive functioning.
Acutely admitted BD I (n = 19) and BD II (n = 32) inpatients who fulfilled the DSM-IV-TR criteria for a major depressive episode were tested with the MATRICS Consensus Cognitive Battery (MCCB), the Wechsler Abbreviated Scale of Intelligence, the National Adult Reading Test, and a battery of clinical measures.
Neurocognitive impairments were evident in the BD I and BD II depression inpatients within all MCCB domains. The numerical scores on all MCCB-measures were lower in the BD I group than in the BD II group, with a significant difference on one of the measures, category fluency. 68.4% of the BD I patients had clinically significant impairment (>1.5 SD below normal mean) in two or more domains compared to 37.5% of the BD II patients (p = 0.045). A significant reduction in IQ from the premorbid to the current level was seen in BD I but not BD II patients. Higher age was associated with greater neurocognitive deficits compared to age-adjusted published norms.
A high proportion of patients with therapy-resistant BD I or II depression exhibited global neurocognitive impairments with clinically significant severity. The cognitive impairments were more common in BD I compared to BD II patients, particularly processing speed. These findings suggest that clinicians should be aware of the severe neurocognitive dysfunction in treatment-resistant bipolar depression, particularly in BD I.
Trial registration number: NCT00664976