Exposure to Psychotropic Drugs and Colorectal Cancer Risk in Patients with Affective Disorder: A Nested Case-Control Study

Background This study aimed to assess the association between the risk of colorectal cancer (CRC) and exposure to mood stabilizers, antidepressants, and antipsychotics in patients with affective disorders. Methods This nested case-control study used data from the National Health Insurance Database of Taiwan collected between 2001 and 2011. All participants in this study had affective disorders. Then, 1209 patients with CRC and 1:10 matched controls were identified based on their demographic and clinical characteristics. A logistic regression model adjusted for demographic and clinical characteristics was used to determine the risk of developing CRC after exposure to psychotropic drugs. Results Among patients with affective disorders, exposure to mood stabilizers (reported as odds ratio; 95% confidence interval; 0.75; 0.57-0.98), antidepressants (0.83; 0.70-0.97), second-generation antipsychotics (0.67; 0.52-0.86), and first-generation antipsychotics (0.65; 0.52-0.81) were associated with a reduced risk of CRC compared to patients who were not exposed. When considering specific drugs, carbamazepine (0.34; 0.12-0.95), valproic acid (0.66; 0.46-0.95), gabapentin (0.44; 0.20-0.99), fluoxetine (0.82; 0.68-0.99), paroxetine (0.63; 0.45-0.87), and venlafaxine (0.72; 0.55-0.95) were associated with a lower risk of CRC. Conclusion Exposure to psychotropic drugs in patients with affective disorders is associated with a lower risk of CRC compared to those who were not exposed. Although the causal relationship between psychotropic drug exposure and reduced risk of CRC could not be inferred directly, these findings may help clinicians and patients in clinical decision-making.