there is a dictum in astrology : mando alasa:
which poorly translated means sani is lazy.
saturn is actually the signifactor for discipline and hence for laziness also.5th house is the house of illumination and spontaniety.when saturn occupies this house, you tend to restrict your horizons of imagination, subconsciously, that you remain relatively closed to new ideas.
i have seen in many horoscopes that inspite of saturn being in 5th house, these people turned out to be superiorly intelligent or creative.
Mozart, Newton, Rabindranath Tagore, Bill Gates, Hitchcock, Jim Morrison, Bob Dylan...
so once again, we can see that just by applying one dictum, the astrologer shouldn't make statements like the person is not creative. One should consider the general nature and yogas of the horoscope. for eg. if there is an influence of shukra/venus in lagna, 4th or 10th it gives an artistic temperament.
yet, saturn and ketu in 5th house will surely give periods of dullness or at least lack of focus to the native.