There are many potential causes of delusions. They include substances that alter thought patterns and affect the brain, such as alcoholic beverages and some illegal and prescription drugs. Delusions might also develop as a symptom of depression or a social phobia. Likewise, a person may suffer from delusions as the result of a mental health disorder, such as schizophrenia.
Sometimes delusions are caused by substances a person consumes. If an individual drinks alcoholic beverages excessively, for instance, he may have delusions as a side effect. A person can suffer this side effect after taking an illegal drug as well, but this issue can also develop when an individual takes prescribed medication. In some cases, this problem may stem from consuming multiple substances that should not be combined. For instance, a person could suffer this adverse effect after taking prescription drugs and consuming alcohol at the same time.
Depression is also among the possible causes of delusions. When a person becomes depressed, this means he has a chronic condition that affects both his mind and his body. A depressed person usually feels sad and disinterested in the things he normally enjoys, and sometimes his feelings are accompanied by physical symptoms, such as difficulty sleeping, loss of appetite, fatigue, and body pain. Many people with depression also consider suicide or have delusional thoughts. For example, a person who is delusional for this reason may firmly believe he will die within a few months, despite the fact that there is nothing wrong with his health and no reason to believe an untimely death is approaching.
Common causes of delusions also include phobias. For instance, a person with a social phobia may suffer the delusion that he is repulsive to other people. He might believe other people cannot stand to look at him, hear what he has to say, or even spend time in the same room with him. Likewise, a person with this type of phobia may believe something awful will happen to him if he engages in a new type of social situation.
Schizophrenia is among of the causes of delusions as well. This mental health condition is marked by abnormal perceptions that distort the affected person's reality. A person with this condition often has trouble organizing his thoughts and speaking in a manner most people consider normal. He may also behave in an erratic, odd, or even disturbing manner. As far as delusions are concerned, he might believe people are out to hurt him when they are not or think someone is following him despite being assured that is not the case.