Hello Welcome to HCM Humira is a new drug that is used in a number of arthritis especially in rheumatoid. He is taking the drug since last 10 months and has recently started showing symptoms like mood swings, irritability, depressive symptoms. The thing that is aggravating the symptoms of irritability and low mood is continuous injections since last 10 months. Repeated injections or any other chronic therapy increased the risk of mood swings. Symptoms of Adjustment disorder like depression, anxiety, mood swings are seen. Even symptoms could be due to disease itself. People suffering from Rheumatoid arthritis and other immunological arthritis also suffer from depressive symptoms. Humira is not known to cause significant depression but it can result in irritability and mood swings. I would advise you to take him to a Psychiatrist for proper evaluation. Proper psychiatric work up and counselling will increase his spirit for treatment and he will feel better. Medicine like low dose antidepressants to decrease depressive symptoms can prove useful. Medicines like low dose benzodiazepines will help to decrease anxiety and depression at times of injection. Thanks