feature of psychotic depression or schizophrenia. Visual hallucinations are generally suggestive of organic conditions such as epilepsy, drug intoxication or drug withdrawal. Many of the visual effects of hallucinogenic drugs are more correctly described as visual illusions or visual pseudohallucinations, as they are distortions of sensory experiences, and are not experienced as existing in objective reality. Auditory pseudohallucinations are suggestive of dissociative disorders. Déjà vu, derealization and depersonalization are associated with temporal lobe epilepsy and dissociative disorders. Cognition This section of the MSE covers the patient's level of alertness, orientation, attention, memory, visuospatial functioning, language functions and executive functions. Unlike other sections of the MSE, use is made of structured tests in addition to unstructured observation. Alertness is a global observation of level of consciousness i.e. awareness of, and responsiveness to the environment, and this might be described as alert, clouded, drowsy, or stuporous. Orientation is assessed by asking the patient where he or she is (for example what building, town and state) and what time it is (time, day, date). Attention and concentration are assessed by several tests, commonly serial sevens test subtracting 7 from 100 and subtracting 7 from the difference 5 times. Alternatively: spelling a five-letter word backwards, saying the months or days of the week in reverse order, serial threes (subtract three from twenty five times), and by testing digit span. Memory is assessed in terms of immediate registration (repeating a set of words), short-term memory (recalling the set of words after an interval, or recalling a short paragraph), and long-term memory (recollection of well known historical or geographical facts). Visuospatial functioning can be assessed by the ability to copy a diagram, draw a clock face, or draw a map of the consulting room. Language is assessed through the ability to name objects, repeat phrases, and by observing the individual's spontaneous speech and response to instructions. Executive functioning can be screened for by asking the "similarities" questions ("what do x and y have in common?") and by means of a verbal fluency task (e.g. "list as many words as you can starting with the letter F, in one minute"). The mini-mental state examination is a simple structured cognitive assessment which is in widespread use as a component of the MSE. Mild impairment of attention and concentration may occur in any mental illness where people are anxious and distractible (including psychotic states), but more extensive cognitive abnormalities