personality inventories with profiles indicati ng mild depression and anxiety, a worrisome
cognitive style, an emotion-focused and intern alizing style of conflict resolution, and a so-
matic focus. Patterns of neurocognitive impairment among individuals with insomnia dis-
order are inconsistent, although  there may be impairments in performing tasks of higher
complexity and those requiring frequent ch anges in performance strategy. Individuals
with insomnia often require more effo rt to maintain cognitive performance.
Prevalence
Population-based estimates indicate that about one-third of adults report insomnia symp-
toms, 10%–15% experience associated daytime impairments, and 6%–10% have symptoms