Abstract

In “Are Normal People Sane?”, Sir Robin will discuss how the seemingly sharp line between the mad and the sane has blurred over time, as evidenced by recent surveys suggesting ~10% of the general population experience hallucinations, focusing particularly on schizophrenia and factors affecting the risk of its development.

In the past it was believed that there was a sharp dividing line between the mad and the sane. About 1% of the population were considered to be incapacitated by a specific mental disease termed schizophrenia which manifested itself as hallucinations (hearing voices) or delusions (fixed false ideas not shared by people from the same culture, and bizarre behaviour), while the remaining 99% were regarded as psychosis-free. However, recent research has shown that isolated or minor psychotic symptoms are much more common in the population than expected, with surveys suggesting that about 10% of the population experience hallucinations or have delusions. Furthermore, the factors which increase the risk of schizophrenia (family history, being born prematurely or with difficult labour, being raised in an urban environment, being a migrant, childhood adversity, heavy use of cannabis, and life events of an intrusive type (e.g. being beaten up) are all also associated with the occurrence of minor psychotic symptoms in the population. Thus liability to schizophrenia-like psychosis is on a continuum which stretches into the general population, and the place of an individual on this continuum is determined by their exposure to the various risk factors. In short, psychosis behaves like many other illness such as hypertension; i.e. blood pressure is normally distributed through the population but doctors impose an arbitrary cut-off at a point where it is raised to a point where it thought beneficial to treat the individual and define people with a blood pressure above this cut-off as suffering from illness. Similarly, there is no sharp dividing line between the insane and the sane with many of the former more rational and many of the latter more irrational than was previously believed.

Everyone is welcome. Free for members, £2 for non-members. Followed by refreshments (That means smoothies, cheese and grapes!).