No , it ' s not that new . It ' s newly commercialized , but it ' s absolutely not new . You can ' t deny that there ' s statistical significance . Your arguments are related to robustity and the integrity of the link . Obviously , it ' s not proven out . She ' s telling her observations of working directly with patients . Yes , the sample size is small . But that doesn ' t preclude statistical significance . It weakens the data , sure , but there ' s still a link here . She ' s 100 % reporting her side of it . When 10 people need such severe treatment and all blame one substance . yes , you can draw a conclusion from that . The actual strength is irrelevant . Personally , I don ' t think there ' s anything to her claims either . Psychosis is a blanket terminology and people prone to psychoses are naturally inclined to use substances . Smokers tend to be more solitary than the average person , and isolation is more heavily linked to psychoses . Thus , I agree it ' s a shitty link with a tiny sample size and a bad conclusion , but it ' s still one point on the overall dataset . Is it an outlier ? As you said , need more numbers . That doesn ' t dismiss the suggested link in this sample , however . Doing so is apologetic and implies you ' ve got some imbalanced views on the subject . No substance is totally safe in excess .