We tested whether mental health workers were prejudiced against personality disorders – here’s what we found


It has long been known that labels, such as mental health diagnoses, can lead people to jump to damaging and erroneous conclusions. The recent Germanwings plane crash led to media stories attributing what happened to the pilot’s depression, and many concluded that there needed to be better ways of excluding depressed people from being pilots.

There have been more balanced views that draw attention to why this is incorrect, but the reality is that mental health labels tend to lead the public to negative conclusions about people who have such diagnoses. This adversely affects the health, employment, relationships and general well-being of those who have the misfortune of falling under particular labels.

Knowing someone who is dealing with mental health issues should reduce negative evaluations and lower stigma, so you would think that those working as therapists in the NHS would be immune to the negative connotations.

Sadly, according to research we conducted at the University of Bath, and published in the British Journal of Clinical Psychology, this is not the case. We found that some psychiatric diagnoses are likely to result in stigma even among professionals. It has been previously suggested that patients with a diagnosis of “personality disorder” tend to be disliked by psychiatrists.

Negative expectations

We systematically tested the idea that a diagnosis of “borderline personality disorder” may be particularly problematic in this way. A person with this kind of “disordered personality”, according to the diagnostic manual DSM5, might be regarded as especially damaged in all areas of life and therefore harder to help. It is a label that is applied to people who have difficulties such as low self-esteem, problems relating to and trusting others as well as extreme mood fluctuations which can be associated with impulsive and risky behaviour. However, such a diagnosis might lead clinicians to wrongly assume other tendencies and behaviour that may not be present for a particular person, such as self-harm and aggression.

This is akin to wrongly judging a book by its cover – offering treatments in response to conditions without fully taking into account a person’s specific needs. Most importantly, the target of our study was to research the issue of therapeutic pessimism. If diagnostic labels sap the optimism of the therapist, then this is likely to adversely affect their efforts to help their patient.

In these circumstances, negative expectations will be noticed by patients, and then become a self fulfilling prophecy. It is already known that the expectations of change, both by therapist and patient, are closely related to actual change.

Testing it out

Take one issue, then add a disorder. Anxiety by Shutterstock

In a controlled experiment we used a video of someone suffering from a relatively simple anxiety problem. We then randomly allocated 265 mental health professionals into three groups, each group given different amounts of “incidental” background information such as family background, unusual behaviour at times of distress and information about a possible past diagnosis of personality disorder.

Before the video started, one group was given simple descriptions about the patient’s general circumstances, including her age and marital status and duration of her anxiety problem, while another was given additional information corresponding to behaviours that could be linked to personality disorders, such as suggested problems with impulse control and switching from intense inappropriate anger to anxiety. A final group was also told that she had previously been diagnosed by a psychiatrist as having a personality disorder. The therapists were then asked to watch and assess what they saw on the video itself, and to make ratings purely on the basis of what they saw in the video.

In fact the diagnosis was incorrect; the person in the video only had an anxiety disorder. Yet we found that therapists’ judgements of the patient were negatively influenced by the label “borderline personality disorder”, but not by the description of the behaviour that corresponded to the diagnosis, or what was observed on video. For example, she was rated as less likely to respond to treatment, to require more time and to be more likely to self harm.

The experiment teases apart the impact of a mental health label from other factors such as the behavioural description that may have led to that diagnosis. It seems that it is not the behaviour that influenced therapists, but the addition of the diagnosis, which made them inappropriately pessimistic.

Professionals may need help understanding prejudice. Circle by Shutterstock

Therapists’ expectations when they first assess patients will influence the later course of treatment. This is why diagnostic labels can be so damaging for a patient, as well as ineffective when it comes to treating them.

If we’re to tackle wider stigma, those working in mental health need especially to be cautious about their own preconceived biases – and mindful of the influence that such labels can have on their own clinical judgements, something that could be improved with better training. What is particularly encouraging in our findings is that the simple description of the specific behaviours, which could lead to a diagnosis, did not have the negative effect of the diagnosis itself.