In patients who do not communicate verbally, there are many cues that can lead a psychiatrist to recognition of psychosis.

Ruth Myers MD (USA) formerly Ruth Ryan

Persons with intellectual disabilities (also called learning disability or mental handicap) and/or developmental disabilities such as autism are vulnerable to the same psychiatric conditions as anyone else (Szymanski et al 1990). Many standard psychiatric diagnostic criteria can be easily adapted to persons who do not use speech to communicate. For example, the criteria around sleep disturbance or appetite changes in diagnosis of mood disorders can be described by others who observe the person.

However, recognition of psychosis (hallucinations, delusions, or paranoia) requires the examiner to try to ascertain the internal perceptual experiences of persons who do not use the same primary spoken language as the examiner. One way to try to gather this information is to observe details of a person’s behaviour and compare these behaviours to those of persons with known psychotic symptoms. The examiner must not only make his or her own observations, but must also very intentionally gather the observational data from those who know the person well.

An additional complicating issue is that many of the same behaviours that might indicate psychosis can also be indicators of equally significant but very different (and much more common) neuropsychiatric phenomena. For example, a person who is experiencing a visual migraine aura might appear to be “looking at things that aren’t there”. Thus, although careful observation is important, it is at least as important to interpret the observations in the context of the person’s other symptoms and life experiences.

The original list of observed behaviours that might be indicators of psychosis was developed by watching verbal persons with severe and persistent mental illness while they were experiencing psychotic symptoms, then asking them to place the symptoms in context (Ryan in Ancill et al 1994b). Nonverbal persons who exhibited similar behaviours were examined in regard to co-occurring symptoms and diagnoses, and specifically in regard to treatment outcome.  [Treatment outcome focused on improved social function, improved subjective sense of well being, improved physical health, reduction of symptoms, and improved participation in community. Sedation and chemical restraint were not considered appropriate or positive outcomes.]  Some people who were initially nonverbal acquired speech and were able to provide additional contextual information.

Symptoms and indicators:

Listed below are some consistent nonverbal behaviours seen in persons with accurate diagnoses of schizophrenia or other conditions associated with psychosis. Listed with each behaviour are the diagnostic caveats which should be considered before making a definite attribution of psychosis.

1.      Person stares to the side or into a blank space, nods and gestures as though hearing conversation others do not hear; this can be an indication of auditory and/or visual hallucinations. Caveats: Some people have been trained to do this on purpose or learn this to occupy themselves (“self talk”). If a person seems to be in complete control of the activity, or is using the activity to avoid necessary tasks, this is less likely an indication of hallucinations. In addition, if the person seems to feel consistently terrorized by the experience, then it is possible that the person is experiencing a flashback or other dissociative event. The presence or absence of other criteria for a post-traumatic condition is important in making the diagnostic distinction. Finally, some believe that these experiences could be related to spiritual phenomena and/or giftedness. One general consensus is that if the experiences are personally enriching and seem to increase the person’s sense of connection with others, they are more likely to represent authentic spiritual experience rather than pathology (Clarke, et al 2001).

2.      The individual seems to be fighting and/or shadow boxing with unseen others; this can be an indication of auditory or visual hallucinations. Caveats are similar to those listed in #1, except that authentic spiritual experiences are not thought to include fighting as a component.

3.      Person seems to be simulating or actually interacting romantically and/or sexually with persons, animals, or objects that are ordinarily part of their sexual repertoire; this can be an indication of tactile hallucination where a person feels as though they are having sex with the indicated person, animal or object when he or she is not doing so. This can also be an indication of auditory hallucinations commanding the person to commit these sexual acts. This can also be an indication of erotomanic delusions in regard to the specified target. Caveats: Unusual sexual activity that is self-injurious can be an indication of current or past sexual abuse, either flashbacks of abuse or indications that the person was trained/coerced to participate in these acts. In addition, some rare forms of unusual complex partial seizures can include sexualized auras and sexual acts. In addition, there are a few people with intellectual disabilities who are also sexual predators. If the sexual behaviour appears to include grooming, stalking, coercion, or other criminal elements, and is more consistent than episodic, then this possibility should be considered. The “not part of the person’s usual repertoire” refers to the caveat that for some people sex with objects is their preferred sexual expression, and is not a manifestation of psychosis (that is, the person does not believe the object to be something other than whatever it is). For others, sexual activity with animals is the ongoing preference, and is not a manifestation of psychosis (the person does not believe the animal is something other than it is). However of course this must be addressed and changed because of the various reasons sexual activity with animals is contraindicated.

4.      The individual brushes unseen material off themselves. This can be an indication of a tactile hallucination. Caveats: Paresthesias, where the function of the sensory nerves in the skin is altered causing numbness and tingling, can be a result of many different endocrine or nutrition problems. In addition, partial flashbacks, where the person feels part of the sensations of past trauma without clear memory of the trauma, can easily be mistaken for tactile hallucinations or hypochondria. One other caveat is that a number of paroxysmal neuropsychiatric phenomena can include tactile sensations. These can include (but are not limited to) complex partial seizures, complex migraine, and antiphospholipid antibody syndrome (Ryan RM, Sundheim STPV, Voeller KKS 1998, Myers RM and Myers SP 2017).

5.      The person wears multiple layers of clothing. This can be an indication that the person is trying to prevent themselves from falling to pieces because of a psychotic feeling that limbs and/or viscera are dropping off the body. Caveats are numerous. Although this was commonly observed in many people with schizophrenia, the reasons reported by the people with schizophrenia had more to do with protecting possessions in unsafe situations (it is harder to steal a person’s clothes or money if these are worn on the person’s body at all times), or keeping warm while living outdoors. In addition some people who have survived trauma develop a habit of wearing extra clothing as a way of feeling safe from assault. Finally, persons with certain sensory integration needs (especially persons with Fragile X Syndrome or certain types of autism) sometimes feel more physically at ease if wrapped in several layers of snug fitting clothing (Sundheim STPV, Myers RM, Voeller KKS, 2006).

6.      The person covers his eyes and/or ears. This can be an indication of an effort to suppress visual or auditory hallucinations. Caveats: This can also be an expression of fear and/or an effort to shut out traumatic memories. In addition, conditions such as Fragile X Syndrome or migraine can confer remarkable sensory hypersensitivities. Ordinary noise levels might be physically painful to some persons with Fragile X. Ordinary light can be physically painful to the person in the midst of a migraine attack.

7.      The person places unusual wrapping (such as feminine hygiene products) around the ankles or wrists, in the ears, or covering other “openings”. This can be an indication the person is trying to keep out perceived invasion by (delusional) sinister forces or hallucinations or might be trying to keep his brain or other parts from leaking out of his body. Caveats: Sometimes people use whatever is at hand to sooth aching joints or to keep warm.

8.      The individual glares with anger and intensity at previously liked people or at strangers. This can be an indication of paranoia or other delusions about the person being glared at. Caveats: Sometimes people who have survived certain forms of abuse experience anger or fear at neutral people who are reminders of abusers. Sometimes people with anxiety develop a hostile and suspicious default comportment as a shield in unfamiliar surroundings. In addition, it is sadly true that a person might start to glare at someone if that person has started to abuse them.

9.      The person wraps bandanas or scarves around the head when this is not congruent with the rest of the person’s clothing. This can be an indication that the person is trying to attenuate auditory hallucinations. Caveats are the same as in #7.

10.  The person wears costumes inconsistent with any known role in reality. For example, a person might dress as a firefighter, in association with a delusion that she or he is a firefighter, even though their job is something entirely different and the person has had no training to become a firefighter. Caveats: The person might be expressing a hope or a wish rather than a delusional belief. Also, the person might be expressing a fact not yet known to others (for example, a genetic male might dress in women’s clothing because she is a transsexual woman). Or the person might be describing a part of their history. For example, one man wore a fake police badge and also punished himself physically every night. It was finally learned that he had been used as a sort of enforcer in a very violent congregate facility, and felt deeply guilty that he had been persuaded to hurt others.

11.  The person inspects food and beverages with extreme and exaggerated suspiciousness and/intensity. A variation is when people decline to eat or drink anything unless she or he has prepared the food or watched the preparation of the food. This can be an indication that the person has a delusion that their food is being poisoned. Caveats: Individuals who have been fed food or drinks with psychotropic medications concealed in them often become suspicious, especially if the effects of the hidden medications have been disagreeable. The same applies if the person has endured certain disgusting settings where food was in fact contaminated with spoilage or insects. In addition, some people were fed food which contained radioactive material or other poisons as part of involuntary medical experiments. These individuals might have developed a reasonable, not delusional, suspiciousness about what their food might contain. Knowing the person’s history and context is essential in developing an understanding of this symptom.

12.  The person grimaces or winces as though tasting something foul. A variation of this is when the person gesturally accuses others of foul flatus (when none has taken place) or other body odours. The person might also perseverate on fire alarms, act like they smell smoke when none is present, or sniff as though smelling natural gas leakage. These can all be indications of olfactory (odour) or gustatory (flavour) hallucinations. Caveats: This type of hallucination sometimes accompanies other psychotic symptoms in conditions such as schizophrenia; however when it occurs in isolation it is almost always due to some other neuropsychiatric disturbance, such as complex partial seizures or complex migraine. In addition, odours and tastes can be partial flashbacks. For example one woman used to fill her mouth with strong tasting candies in an apparent effort to block her sense of taste. It was later learned that she had been orally raped (forced to fellate a man who was a caregiver) and when she received therapy around this assault the need to block her sense of taste remitted.

13.  The individual runs in circles to the point of collapse. This can be an indication that the person believes he or she is being chased by a hallucination or has a delusion of persecution. Caveats: The most common reason that people runs in circles to the point of exhaustion turns out to be a medication side effect, specifically akathisia. Persons with intellectual and/or developmental disabilities are more vulnerable to this medication side effect. Also, some people find that relentless physical activity can partially attenuate anxiety or physical pain in almost any area of the body.

14.  The person hides from familiar previously trusted people. This can be an indication that the person has become delusional or paranoid. Caveats: Unfortunately the most common abusers of persons with disabilities are the people who provide care. The first thought if someone starts hiding from a caregiver should be to determine if there is a problem with the caregiver.

Symptoms which are almost never indications of psychosis:

There are some symptoms which, although sometimes dramatic in presentation, are almost never indications of psychosis.

1.      Volitional self talk and self answering, sometimes using a variety of vocal inflections and tones.

2.      Shouts and screeches are almost always vocal tics and not indications of a psychotic process.

3.      Symptoms which are modelled by others and are very clearly being copied.

4.      Gestures that the person can start and stop at will or when asked to start and stop.

5.      Gestures and vocalizations which have been explicitly taught to the person.

6.      Lofty, seemingly grandiose dreams or hopes. In years past there was a sense that people who reported grand dreams or hopes were either delusional or failed to appreciate the realities of the disability/disabilities. In fact, it is now well known that the presence of high hopes is a sign of health.

Epidemiology Considerations:

Between 70% and 85% of persons with intellectual developmental disabilities referred for psychiatric assessment are found to have one or more untreated, undertreated, or undiagnosed co-occurring non-neuropsychiatric medical problems influencing mental health and behaviour (Ryan and Sunada, 1997; Sundheim et al 1998). Many of these conditions can produce delirium and/or psychosis (Ryan et al 1998). If an additional condition is identified and not treated the person will obtain little or no relief from antipsychotic medication and will experience complications of the untreated problem and the not-inconsiderable side effects of the medications. Therefore it is essential to investigate thoroughly for co-occurring medical conditions which might produce symptoms of psychosis or delirium.

Between 60% to 100% of persons with intellectual disabilities experience severe trauma, usually abuse (Sobsey 1994). Some (but of course not all) of those who endure trauma develop post-traumatic stress disorder. This condition produces a number of symptoms which can easily simulate psychosis (see examples above) but require an entirely different treatment approach.

Even if psychosis is strongly suspected, the most likely causes are complications of severe mood disorders and certain neurophysiologic conditions, such as unusual seizures with ictal or peri-ictal hallucinations. One of the least likely diagnoses underlying psychosis is schizophrenia. Of course schizophrenia does occur in people with intellectual disabilities, but is probably no more common than in the general population (Szymanski and Crocker, 1989). When schizophrenia is suspected, three additional symptoms are often present. These include:

1.      Problems with initiation: persons with schizophrenia often are uniquely unable to initiate even familiar activities when the intensity of the illness is increased.

2.      Problems with sensory gating function:  specifically people with schizophrenia (and to some extent their first degree relatives) have trouble with the automatic sorting and prioritization function in the brain (Adler LE et al. 1982) As a result, the person might become confused and disoriented (and experience an increase in hallucinations) in stimulating settings, even those activities that the individual enjoys. In practice, the individual is observed to become disengaged, confused, glassy eyed and less responsive in desired stimulating situations, such as shopping centres, a busy job, or a party with friends. Caveat: persons with anxiety disorders might also appear confused and disoriented in stimulating situations, however they usually also appear anxious rather than psychotic.

3.      Individuals with schizophrenia often express affect that seems to contradict content. For example the person with schizophrenia might laugh in a lighthearted way at visual stimuli that others find frightening or terrifying.

Other issues:

It is also important to be aware of possible idiosyncratic explanations for symptoms that are suspected to be psychosis. For example, one woman (who was nonverbal and nonvocal) with a family history of schizophrenia and many eccentric mannerisms was observed to wave her hands at unseen stimuli. She received several trials of antipsychotic medications which produced no benefit. One day she tried on a pair of eyeglasses offered by a nearsighted clinician, and all the unusual mannerisms disappeared. Severe myopia had been mistaken for psychosis.

Of course it is essential to attempt to interview all individuals, even those who are not thought to use or understand speech. Many understand more than cognitive testing suggests, and can give helpful answers via gestures, nods, drawings, and non-speech vocalizations (Ryan 2001, Stavrakaki and Klein 1986, Trumble, 1993). An award winning series of picture books has been developed for use in this sort of interviewing (Hollins S et al).

It can also be helpful to obtain videotape of symptoms so that observers can re-examine the behaviours as additional contextual information is obtained. For example, defensive gestures might seem inexplicable or delusional at first, and then may be quite understandable when the person’s trauma history is discovered.


Observation of the nonverbal communications of persons with intellectual disabilities can offer clues to psychotic symptoms such as hallucination, delusions, and paranoia. The observations of those who know the individual very well, such as family members and caregivers, are essential in gathering these data. The meaning(s) of these nonverbal communications can best be understood when placed in the context of the person’s history, medical status, and environmental context. It is essential to interview the person, regardless of their supposed ability to understand. Any diagnostic hypothesis can only be considered valid if the resulting treatment produces improved quality of life and function and also provides relief of physical and/or emotional pain.


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This article, which has been adapted, first appeared in the Psychiatric Times December 2001, Vol. 18(12). It was revised in December 2010, and again in July 2017.