ɪn nˈaɪntiːnhˈʌndɹɪd sˈɪksti fˈaɪv, kɹˈɪstəl spɹˈɛndʒəl ɛkspɹˈɛst kənsˈɜːnz ɐbˌaʊt lˈʌdwɪɡz mˈɛntəl hˈɛlθ ɪn ɐ lˈɛɾɚ tə swˈɪs ˈɑːɹt hɪstˈoːɹiən wˈɜːnɚ mjˈuːəlɚ; ʃiː stˈeɪɾᵻd ðæt lˈʌdwɪɡ wʌz kənfjˈuːzd ænd ɪmˈoʊʃənəli ˈæbsənt.
In 1965, Christel Sprengel expressed concerns about Ludwig's mental health in a letter to Swiss art historian Werner Mueller; she stated that Ludwig was confused and emotionally absent.