How ‘Confirmation Bias’ Harms Mental Health Patients

Recently, I spent the majority of a 90-minute therapy session processing a highly invalidating experience where someone questioned my borderline personality disorder (BPD) diagnosis. As we discussed the man’s questions and actions, my therapist helped me reframe the situation. Then, she brought up a term I had previously only associated with true crime shows: confirmation bias.

Essentially, confirmation bias is the tendency to interpret new evidence as confirmation of one’s existing beliefs or theories. In other words, once someone makes up their mind about something, they stop questioning and start tallying up the information that helps support that decision. And although this may sound silly, nearly all humans engage in confirmation bias in our everyday lives. In fact, many of us spend more time looking for confirmation for our beliefs and insecurities that we miss out on many opportunities because we’re held hostage by our perceived assumptions.

However, I never thought I would experience confirmation bias from a mental health care provider.

As I prepared for discharge from my local psychiatric hospital’s intensive outpatient program over two years ago, the social worker managing my case helped me find a dialectical behavior therapist in the area. Although that social worker never officially diagnosed me with BPD, this new therapist (a licensed clinical psychologist) only needed one 90-minute interview to put the pieces of my life together and help me confirm that a BPD diagnosis fit me well. After all, my 15-year history with self-harm and suicidal ideation lumped with multiple hospitalizations and attempts definitely fit the bill of a “stereotypical borderline’s” behaviors.

For the next 18 months, everything became further evidence for that initial interview. I often displayed intense emotional reactivity both inside the office and in my everyday affairs. I struggled to maintain boundaries even with the therapist, let alone anyone else. I made impulsive choices that frequently threatened my relationships and sometimes even my own well-being.

And although I fully agree with that psychologist’s BPD diagnosis, my current therapist made a valid point during that recent processing season: My former therapist never stopped to consider the true “motives” behind many of my actions.

The truth is that I am not only a highly sensitive person (HSP), but I also spend most of my waking hours in a state of anxious hypervigilance. From a young age, I learned to expect abandonment and trust no one. Add to that my history of sexual trauma and repeat relationships with emotionally abusive men, and you create the perfect storm of someone who feels entirely unlovable and chronically empty. And although those symptoms all line up with the DSM-5’s BPD criteria, they also line up with post-traumatic stress disorder (PTSD) and a slew of other diagnoses.

Confirmation bias isn’t just limited to me, though. In fact, upwards of 13% of psychiatrists engage in confirmation bias when studying new information after making an initial diagnosis. Ultimately, confirmation bias can lead to a fatal chain of wrong decisions for patients, especially when it comes to mental health conditions. When professionals make judgment calls based on confirmation bias, they can invalidate their patient’s perspective, make clinical decisions that don’t benefit the client, or even prescribe unneeded medications.

In my specific case, I don’t feel that my former clinician’s confirmation bias caused any long-term effects, but it did ultimately lead to a breakdown in our therapeutic relationship.

Thankfully, my current therapist is working hard to “untease” all of my complexities and the numerous overlapping symptoms I display. While this is a lengthy and costly process, I know the ultimate goal is to paint a clear picture of my symptomology so that we can ultimately develop a treatment plan that meets my actual needs instead of blindly placing Band-Aids all over my body in hopes of stopping me from bleeding out.

I hope that by sharing this story, I can draw a new awareness to confirmation bias within the field of mental health and somehow start more conversations between care providers and their clients. All clinicians owe it to their patients to not only look for the easy path and most obvious diagnosis, but to take all the evidence into consideration and make the best-informed decision they possibly can.