Why hallucinations occur

People can experience hallucinations when they're high on illegal drugs such as amphetamines, cocaine, LSD or ecstasy. They can also occur during withdrawal from alcohol or drugs if you suddenly stop taking them.

Drug-induced hallucinations are usually visual, but they may affect other senses. They can include flashes of light or abstract shapes, or they may take the form of an animal or person. More often, visual distortions occur that alter the person's perception of the world around them. The hallucinations can occur on their own or as a part of drug-induced psychosis. After long-term drug use, they may cause schizophrenia. Some people take cannabis to "calm themselves" and relieve their psychotic symptoms, without realising that in the longer term, the cannabis makes the psychosis worse.

Heavy alcohol use can also lead to psychotic states, hallucinations and dementia. Find out how to get help for a drug problem. Various prescription medicines can occasionally cause hallucinations.

Elderly people may be at particular risk. Hallucinations caused by medication can be dose-related and they usually stop when you stop taking the medicine. However, never stop taking a medicine without speaking to your doctor first and, if necessary, after being assessed by a psychiatrist. Speak to your GP about how the medication is affecting you, so you can discuss the possibility of switching to another medicine.

Some people experience hallucinations just as they're falling asleep hypnagogic , or as they start to wake up hypnopompic. The hallucination may take the form of sounds, or the person may see things that don't exist, such as moving objects, or a formed image, such as a person the person may think they've seen a ghost.

Hallucinations are sensory experiences that appear real but are created by your mind. They can affect all five of your senses. These symptoms may be caused by mental illnesses, the side effects of medications, or physical illnesses like epilepsy or alcohol use disorder.

You may need to visit a psychiatrist, a neurologist, or a general practitioner depending on the cause of your hallucinations. Treatment may include taking medication to treat a health condition. Your doctor may also recommend adopting different behaviors like drinking less alcohol and getting more sleep to improve your hallucinations. The hallucinations may be of objects, visual patterns, people, or lights. Olfactory hallucinations involve your sense of smell.

This type of hallucination can also include scents you find enjoyable, like the smell of flowers. Gustatory hallucinations are similar to olfactory hallucinations, but they involve your sense of taste instead of smell.

These tastes are often strange or unpleasant. Gustatory hallucinations often with a metallic taste are a relatively common symptom for people with epilepsy. Auditory hallucinations are among the most common type of hallucination. You might hear someone speaking to you or telling you to do certain things.

The voice may be angry, neutral, or warm. Other examples of this type of hallucination include hearing sounds, like someone walking in the attic or repeated clicking or tapping noises. In sleep paralysis, your mind wakes up, but your body does not. You may also experience frightening hallucinations.

What is this, and how can we cope? Night terrors are a common experience. They are not medically significant, but they can be distressing.

They are more common in children than in…. Tactile hallucinations involve sensations that are not explained by outside physical factors, such as that bugs are crawling over the body, or that…. What really happens in the brain during a hallucination? Written by Maria Cohut, Ph. So what is a hallucination? It's a "false perception" of reality and it can occur with a whole range of senses, but the most common ones are visual and auditory hallucinations, said Professor McGrath.

Normally our brain is good at distinguishing between a sound or image that is occurring in the outside world, and one that is just a product of our mind. But occasionally something can go awry. One major theory is that hallucinations are caused when something goes wrong in the relationship between the brain's frontal lobe and the sensory cortex, said neuropsychologist Professor Flavie Waters from the University of Western Australia.

For example, research suggests auditory hallucinations experienced by people with schizophrenia involve an overactive auditory cortex, the part of the brain that processes sound, said Professor Waters. Similarly, people with Parkinson's disease appear to have an overactive visual cortex, which results in images being generated in their brain of things that aren't actually there.

Psychoactive drugs could also upset the relationship between the sense processing parts of the brain and the frontal lobe in a similar way, said Professor Waters. The big question is whether the same kind of processes are responsible for less extreme hallucinations. Hallucinations aren't always intrusive, negative and scary, even in conditions like schizophrenia. About 70 per cent of healthy people experience benign hallucinations when they are falling asleep, said Professor Waters.

This includes hearing their name being called, the phone ringing or seeing someone sitting at the end of their bed. Research into this kind of hallucination is in its very early days, said Professor Waters.