A delusion is a belief that is not based in reality. While many people within the same culture may share beliefs that are not proven and that may even seem implausible to people outside of that culture, delusions are incorrect beliefs that are not shared by other people of the same culture.
Delusions are a somewhat controversial phenomenon, given that beliefs are highly individual and are often based on opinion and misinformation, as much as on fact and direct experience. Many of the delusions that people with psychosis or people affected by psychoactive drugs experience have some basis in reality or cannot actually be disproved. What makes delusions different from ordinary inaccurate beliefs is the extent to which they are removed from reality and the intensity with which they affect the person having the delusion.
Delusions are quite a serious problem and can lead people into trouble unpredictably. Therefore, it is important that anyone who is developing delusions seek medical help as soon as possible. Don't worry about getting into trouble if your delusions started after taking drugs. The doctor is only interested in your mental and physical health, and will not report what you tell him or her to anyone else unless there is an imminent risk of harm to yourself or someone else. But to help you properly, the doctor needs to know how the delusion started.
There are certain types of delusions that commonly occur:
Delusions of Grandeur
People who have delusions of grandeur believe they are special and more important than other people. While one person's importance can be greater than others in certain situations - for example, most people would agree that a visiting celebrity is the most important person at an event - delusions of grandeur cause the person to think they are more important than others, even when there is no particular reason or objective evidence for it. Sometimes, the delusional person believes he is a famous person or that he has a special relationship with a famous person.
Grandiosity can be an effect of some psychoactive drugs, most notably cocaine and crystal meth. This crosses over into delusion if the person is unable to see himself objectively, and develops an exaggerated sense of his importance, specialness or self worth. Sometimes, the delusion is in stark contrast with the reality of the way the person is perceived by others.
Persecutory DelusionsOften called "paranoid" delusions, people having persecutory delusions believe that others are acting against them. This can range from thinking that other people are thinking negative thoughts about them to believing that others are plotting against them or trying to kill them.
Having persecutory delusions about the medical profession can make it especially difficult for people having delusions to seek help. It requires courage to trust that a doctor or therapist will really help you if you believe they are not acting in your best interests. Well-trained professionals understand this difficulty and will do their best to reassure you that they do, in fact, want to help you get better.
Relationship DelusionsThere are several types of delusions involving relationships. Some people develop delusions that someone, often a famous person, is in love with them. Others become convinced that their partner is being unfaithful. It can become very confusing for someone having these delusions to make sense of their relationships, and it can be upsetting for partners.
Of course, some partners who are actually being unfaithful will accuse a partner of being delusional, when they are in fact correct in their suspicions. This is known as "gaslighting," and it is particularly difficult for someone with a history of delusions to cope with.
Somatic DelusionsA whole range of delusions involving imagined diseases or defects can be experienced. They can range from believing you are ugly when you are not, to believing you are riddled with disease or parasites. These delusions are extremely unpleasant and may be accompanied by tactile or visual hallucinations that seem to prove the delusion to be true.
A common delusion that people who are high on meth experience is the belief that there are bugs crawling all over their bodies or even under their skin. They may scratch and pick at their skin in an effort to rid themselves of these imagined parasites. Often, this results in unsightly scabs, sores and scarring.