A recent study found no evidence of seasonal affective disorder in Iceland where the sun does not appear for a long time in the winter.
The sun doesn't appear during winter in Iceland.
The text states that the sun doesn't appear for a long time, not that it doesn't appear at all.
( z1 appear :polarity - :ARG1 ( z2 sun ) :time ( z3 date-entity :season ( z4 winter ) ) :location ( z5 country :name ( z6 name :op "Iceland" ) ) )