Tumor Necrosis Factor Alpha antagonists, which are used for the treatment of inflammatory diseases, are considered to beassociated with psychiatric diseases.Herein we have reported an adult ankylosing spondylitis case with psychotic depressioninduced by adalimumab therapy and improved after treatment. We aimed both to discuss the relationship between psychiatricdisease and inflammatory factor over this case and to make contribution to the literature. A 57-year-old male patient. He hadexperienced depressive symptoms nearly 5 months ago after 15 days of adalimumab therapy started for ankylosing spondylitis.Meanwhile, the symptoms of the patient, who continued adalimumab therapy once every two weeks, progressed andaccompanied by psychotic symptoms such as disorganized speaking and behavior. The patient was admitted to the psychiatryclinic; however, his complaints did not significantly improve with treatment but rapidly regressed after discontinuation ofadalimumab therapy. To our knowledge, there is limited data on the mood episodes triggered by adalimumab. In the presentcase, presence of a connection between symptom onset and the date of starting the medication, as well as rapid symptomregression with discontinuation of the medication, was considered as “potential adverse drug effect” according to the NaranjoAlgorithm. This suggests that alteration in proinflammatory processes such as Tumor Necrosis Factor (TNF) might be associatedwith the onset of mood episodes. Further studies would be important in understanding the role of immune system in thepathophysiology of depression, particularly the sub-types such as psychotic depression.