Why is it that some people develop a mental health difficulty and others don’t? As with most of life’s big questions, there isn’t a straightforward answer, and different professionals can often give different answers, which can be confusing. However, this can be an important question to explore in therapy because what causes you to struggle with your mental health is personal to you.

There is one model that I tend to lean towards when thinking about mental health and that is something called the Stress Vulnerability Model. Developed by Zubin et al. in 1977, this model explored why some people developed a psychotic illness and others did not. However, I believe that the model itself can be applied to many other types of emotional suffering.

Essentially, the authors propose that every single one of us has some degree of vulnerability that would put us at risk of developing a mental health difficulty. These vulnerabilities can include, for example, biology / genetics (e.g. if a family member has experienced a mental health problem), trauma, abuse, loss, social isolation, poverty, neglect etc. It also suggests that each one of us would at some point in our lives be exposed to stress of some sort, for example loss, illness, financial difficulties, work related stress, relationship difficulties etc. etc. Those people with multiple vulnerability factors may be more at risk of developing a mental health difficulty when exposed to lower levels of stress than someone who has fewer areas of vulnerability. Someone with few vulnerability factors may be able to tolerate higher levels of stress than those with greater vulnerability – but every single person would still have their tipping point and no one is completely protected.

This model is also really helpful for understanding a relapse in your mental health. It is also really important to remember that our personal vulnerability is not a static concept and that it can change with time. So for instance, experiencing loss, trauma or mental health difficulties throughout our lives may increase our vulnerability to developing (or having a relapse of) a mental health difficulty.