Primary prevention

Vaccines have saved more lives than antibiotics. It would be better to nip mental disorders in the bud than to wait for them to develop and so it has often been suggested that psychiatrists redirect some of their energies to prevention (Bhui ' Dinos, 2011). But how do you prevent something you do not understand? The biological causes of severe mental disorders remain largely unknown. Thomas Insel (2009), director of NIMH in the USA, has suggested that whole genome scans could be used to identify vulnerability markers. However, 10 years after the introduction of that technology, too little has been learned and most of the studies using it have been fishing expeditions.

One can accept that severe mental disorders are rooted in neurobiology (Insel ' Wang, 2010). Yet the devil lies in the detail. No single gene explains more than a small percentage of variance, and there are no data showing that even a few major genes can predict mental illness with any accuracy. Moreover, most neuroscience models fail to consider interactions with the environment, or to consider seriously the implications of epigenetics. The idea that physicians can accurately predict risk for any individual remains a pious hope.

Prevention of psychological adversities is also dubious. Life is full of negative events of all kinds. And if you think that families are to blame for some forms of mental disorders, just try regulating parenting. Although some studies support the use of parental education to reduce the incidence of behavioural disorders in children (Hutchings et al, 2007), it would be premature at this point to generalise from samples in randomised controlled trials to broader clinical populations.

Preventive psychiatry has emphasised social interventions that might affect the prevalence of mental disorders (Paykel ' Jenkins, 1994). There is certainly evidence that social stressors (such as poverty and powerlessness) are risk factors (Scheid ' Brown, 2010; U'Ren, 2011). These findings may have importance for global mental health (Patel ' Prince, 2010).