Brief psychotic disorder: symptoms, causes and what happens next

Psychosis is a term used for losing some contact with reality. The NHS explains that it may involve seeing or hearing things that other people cannot (hallucinations) and believing things that are not true (delusions), along with confused thinking and speech. Experiencing these symptoms is often referred to as having a psychotic episode.

Brief psychotic disorder is a diagnosis used by psychiatrists when this kind of episode is short. According to the MSD Manual, the symptoms resemble those of schizophrenia, but last for a much shorter time, from 1 day to 1 month, and a diagnosis is made when symptoms last less than 1 month and another disorder does not better account for them. If it occurs during an episode of marked stress, the MSD Manual calls it brief reactive psychosis.

The UK public sources used for this guide, including the NHS and Rethink Mental Illness, do not give brief psychotic disorder a page of its own. Rethink lists a brief psychotic episode among the conditions psychosis can be related to. This guide therefore draws general information about psychotic episodes from the NHS and uses the MSD Manual, a US-based reference, only for the definition and outlook of this particular diagnosis.

The NHS says hallucinations may involve hearing, seeing and sometimes feeling, smelling or tasting things that do not exist outside the mind but feel very real, and that hearing voices is a common one. A common delusion is believing there is a conspiracy to harm you. Disordered thinking and speaking means thoughts and ideas come very quickly, which can make speech fast and confusing.

The MSD Manual states that a person with brief psychotic disorder has at least one of delusions, hallucinations, disorganised speech, or very disorganised or catatonic behaviour. NHS inform adds that during a psychotic episode most people do not realise they are ill, and that friends and family may find it hard to understand why the person is reacting so strongly to things they cannot see or hear.

• Hearing voices or other sounds that others cannot hear.

• Strong beliefs that are not shared by others, such as that someone is trying to harm you.

• Speech that is fast, jumps between topics or is hard to follow.

• Behaviour that is very disorganised or out of character.

• Marked distress, fear or agitation, and a change in how the person behaves with others.

The NHS says you should see a GP immediately if you are experiencing symptoms of psychosis. If you are concerned about someone else, you could contact a GP for them, or their mental health worker if they receive support from a mental health service.

If the person seems to be at risk and needs urgent treatment, the NHS says you can take them to A&E if they agree, call their GP or an out-of-hours GP, or call 999 and ask for an ambulance. NHS 111 can also advise, and the NHS says to call 999 if you think someone is an immediate threat of danger to themselves or others. People who have experienced psychosis have a higher than average risk of self-harm and suicide, according to the NHS, so anyone who is thinking about ending their life should call 999 or go to A&E.

There is no single cause. Rethink Mental Illness says researchers suggest that the environment and a person's genetics may cause psychosis, and that physical health problems such as a brain tumour can also be responsible. Stressful life events, losing a job, drug and alcohol misuse or withdrawal, delirium, grief, childbirth and tiredness are listed among the life experiences that can trigger psychosis or a relapse.

The NHS lists schizophrenia, bipolar disorder and severe depression as conditions that may cause psychosis, along with a traumatic experience, stress, drug misuse, alcohol use disorder, side effects of prescribed medicines, brain tumour or dementia, head injury and childbirth. Because many of these are treatable or reversible, doctors will ask about medicines, substance use and physical health at the first assessment. The MSD Manual names adverse effects of medicines or drugs, brain tumour, temporal lobe epilepsy, schizophrenia and schizoaffective disorder as other conditions that can produce similar symptoms and need to be considered.

The NHS says there is no test that positively diagnoses psychosis. A GP will ask about your symptoms and possible causes, including medicines, alcohol and drugs, mood, day-to-day functioning, family history of mental health conditions, details of any voices or beliefs, and whether you have harmed yourself or thought about it. The GP will usually refer you urgently, because evidence supports early treatment.

Depending on local services you may be seen by a community mental health team, a crisis resolution team, or an early intervention team for a first episode. A psychiatrist carries out a full assessment to identify any underlying condition. The NHS says these teams can include psychiatrists, community mental health nurses, psychologists and social workers.

Whether the label brief psychotic disorder fits depends on the length of the episode and on ruling out other explanations, which means the length of an episode can only be judged once it has passed. The MSD Manual notes that doctors diagnose it when symptoms last less than a month and another disorder does not account for them.

The NHS says treatment for psychosis usually combines antipsychotic medicine, talking therapies and social support, and depends on the cause. First episodes may be managed by an early intervention team that offers assessment, medicine, talking therapies and social, occupational and educational support. The MSD Manual describes treatment of brief psychotic disorder as similar to that of schizophrenia, requiring a doctor's supervision and sometimes short-term antipsychotic treatment.

The NHS explains that antipsychotics can reduce anxiety within a few hours but may take several days or weeks to reduce symptoms such as hallucinations or delusions, and that some people stay on them long term while others can gradually reduce and stop. It warns against stopping suddenly, because that could trigger a relapse. For a short episode, how long to continue medicine is a decision for the psychiatrist and the person together.

The MSD Manual states that relapse is common in brief psychotic disorder, but that people typically function well between episodes and have few or no symptoms. It also says people with the diagnosis appear to be at increased risk of developing schizophrenia or another condition on the schizophrenia spectrum. For that reason a follow-up plan, rather than discharge after the first recovery, is common.

Practical steps are those the NHS lists for psychosis in general: keep to your care plan, tell the team about side effects, avoid alcohol and drugs that can worsen symptoms, and ask for a plan for what to do if symptoms return. The NHS also says you can make a legally binding advance decision about treatments you do not want, though it can be overruled if you are detained under the Mental Health Act. Do not drive during an episode, and the NHS reminds people that it is a legal obligation to tell the DVLA about conditions that could affect driving.

Support for families is available. NHS inform points relatives to the charity SAMH, and Rethink Mental Illness and Mind offer information and local groups.

On the NHS, a first episode is usually managed through the GP, the crisis or early intervention team and a psychiatrist, without charge. In an emergency the right route is A&E, 999 or NHS 111.

Some people choose a private psychiatrist for a quicker assessment or a second view, and the medicines and therapies are the same. Because a short psychotic episode needs ruling out of physical causes and substance use, whichever route is used, ask for the results to be shared with the GP so follow-up is not lost.