Above: Environmental factors which increase the risk of developing mental illness. Childhood adverse experiences, especially when repetitive and chronic, are frequently particularly damaging.

We have seen that those of us who suffered significant childhood trauma are far more likely than those who were fortunate enough to experience a relatively stable upbringing to develop mental (and, indeed, physical) health problems in later life (all else being equal) – e.g. see my article on the Adverse Childhood Experiences (ACE) Study.

However, when in comes to treating mental disorders, there exist two distinct approaches; we can call these the nature approach and the nurture approach; I explain how these two approaches differ from one another below.

Research indicates that both nature and nurture (e.g. genes and environment) contribute to mental illness (e.g Tsuang et al., 2004) and it is how these two factors interact that is crucial. (One might inherit genes that make one susceptible to developing a particular mental illness, but only go on to actually develop it if one’s environment conspires against one too (e.g. severe and protracted childhood trauma).

1) The Nature Approach:

Mental health professionals who use the nature approach assume the mental disorder is caused by physical factors such as:

– genes

– neurological biochemistry

– hormone dysregulation

Therefore, the treatments such mental health professionals use seek to correct the assumed physical problem; these include:

– drugs that alter the brain’s biochemistry such anti-depressants that change levels of serotonin in the brain and anti-psychotics that alter levels of dopamine in the brain

– transcranial magnetic stimulation

– electroconvulsive therapy

– implants of electrical devices

– vagus nerve stimulation

2) The Nurture Approach :

Those who take this approach regard one’s environment as being the cause of one’s mental illness. Such environmental factors include, for example :

– society

– culture

– family

– war

– parental neglect/abandonment/rejection/abuse

– poverty

– social ostracization

Treatments based upon the nurture approach include :

– attempts to improve the individual’s environment

– psychotherapy

– counselling


The truth is, however, that mental illness is caused by the ways in which physiological and environmental factors interact with one another.

Notwithstanding the above, it is also the case that the development of some mental illness is contributed to more by the genes we have inherited than by the environment within which we have existed and visa versa.

For example, the risk of developing schizophrenia, the latest research suggests, appears to have a genetic contribution of about 80℅ (although it follows from this, of course, that environment still plays a significant role – indeed, there is no one specific gene that causes schizophrenia). Also, it should be pointed out, this figure of 80 per cent is questionable due to research limitations.

By over-focusing on the physical underpinnings of mental illness clinicians may neglect to properly examine vital environmental/psychological contributing factors, and visa versa.


Rikke Hilker et al. 2017 Heritability of Schizophrenia and Schizophrenia Spectrum Based on the Nationwide Danish Twin Register. ARCHIVAL REPORT| VOLUME 83, ISSUE 6, P492-498, MARCH 15, 2018. 017DOI:https://doi.org/10.1016/j.biopsych.2017.08.017
Ming T Tsuang et al., 2004.Gene-environment interactions in mental disorders. World Psychiatry. 2004 Jun; 3(2): 73–83.


David Hosier BSc Hons; MSc; PGDE(FAHE).