Relapse: Definition

In schizophrenia, relapse usually refers to a clinically meaningful increase in psychotic symptoms or related impairment following improvement. It may involve returning voices, stronger delusional conviction or greater disorganisation. Some research definitions use symptom scores, hospital admission or a treatment change, but these measures do not capture identical events.

Relapse means a significant return or worsening of illness symptoms after a period of improvement. Definitions vary across clinical services and research studies. A brief fluctuation is not automatically a relapse, and changes should be interpreted against the person’s usual pattern, functioning and circumstances rather than one isolated sign.

A useful clinical definition considers severity, duration and practical consequences. The person’s own experience matters: deterioration may be evident to them before others notice. Conversely, a single poor night or passing unusual thought may not indicate relapse. Assessment looks for a pattern and checks other explanations, including depression, substance effects and physical illness. Clear documentation helps distinguish recurrence from symptoms that never fully settled. The term should guide additional care rather than imply that all earlier progress has been lost.

Definitions influence reported rates. Hospital admission can reflect service access or social circumstances as well as symptom severity, while a symptom threshold may capture changes managed in the community. Comparing studies therefore requires attention to the outcome used. Clinically, a clear description of the actual change is more useful than assuming the word relapse has one universal meaning.

Further reading: National Institute of Mental Health; NICE clinical guideline.