Cognitive Deficits Persist Through Bipolar Disorder Remission

Historically, psychiatrists believed that patients with bipolar disorder (BPD) recovered fully between mood episodes and experienced no residual symptoms during remission. Now, recent findings indicate that this may not be true.

Bipolar patients exhibit cognitive impairment during mood states, and that impairment persists during euthymia. These cognitive deficits contribute to functional impairment and can create a heavy burden of symptoms and societal costs, in addition to a clinical management conundrum. To top it off, the FDA has not yet approved any drug therapy for the management of cognitive deficits in BPD.

Psychiatry practitioners from the University of Texas Health Science Center at Houston addressed the challenge of cognitive impairment in BPD in a recent paper that appeared as an early electronic publication in the American Journal of Therapeutics on November 7, 2014. In that article, the authors described the pharmacological and nonpharmacological treatment of cognitive deficits among bipolar patients.

Poor verbal memory, psychomotor speed, and response inhibition may be cognitive indicators of genetic vulnerability to BPD, the researchers explained. Among the agents traditionally prescribed and dispensed for the mental disorder:

• Lithium has been associated with few cognitive effects.
• Anticonvulsants have been linked to psychomotor retardation and memory and attentional decline.
• Antipsychotics’ cognitive effects have only been examined in a few BPD studies.

A number of other agents—including cholinesterase inhibitors, memantine, mifepristone, intranasal insulin, pramipexole, herbal agents, and supplements—have been tested as treatments for BPD’s cognitive deficits, but the results have been mixed. The authors suggested that medications might confer only marginal benefit for cognitive deficits, as scientists have not yet determined which deficits are more likely to respond to therapeutic interventions.

Nevertheless, 2 nonpharmacological interventions seem promising:

• Cognitive remediation, which is a form of neuropsychological rehabilitation that uses training-based intervention focused on improving cognitive processes by compensatory and adaptive strategies, and
• Noninvasive brain stimulation techniques, including transcranial magnetic stimulation.

Still, more research is needed to determine whether those processes help patients with BPD.

The researchers highlighted the growing evidence that inflammatory processes underlie BPD’s pathophysiology, noting correlations between inflammatory cytokines and cognitive impairment—a promising avenue of exploration into the mental disorder.