Several studies, smoking status (i.e., smoker or non-smoker) or measures of smoking consumption (e.g., pack years), showed weak or no relationships to specific neurocognitive functions (e.g., measures of learning and memory, mental arithmetic, verbal fluency, processing speed), global neurocognitive function (e.g., MMSE) and neurocognitive decline in young and middle aged adults [62,63] and in large community-based samples consisting of middle-aged and older adults [64–70].
