Borderline Personality Disorder (BPD) is a complex mental illness that is often difficult to diagnose because it generally co-occurs with other disorders. These other disorders can mask the symptoms of BPD, often leaving the underlying disorder untreated.
The five conditions that most commonly co-occur with BPD are:
- Mood disorders
- Anxiety disorders
- Post-Traumatic Stress Disorder (PTSD)
- Substance abuse
- Eating disorders
BPD commonly co-occurs with mood disorders such as depression and Bipolar Disorder. Rates of depression in people with BPD can be as high as 60 percent, according to the National Institute of Mental Health (NIMH).
As many as 20 percent of people with BPD may also have Bipolar Disorder. Because both BPD and Bipolar Disorder are characterized by unstable moods, impulsivity and interpersonal difficulties, it may be difficult to recognize which disorder is causing the symptoms.
People with BPD often experience debilitating anxiety, panic attacks and excessive worrying that can be symptomatic of BPD or of a co-occurring anxiety disorder. There are several anxiety disorders that can co-occur with BPD: Panic Disorder, phobias, Obsessive Compulsive Disorder (OCD), Social Anxiety Disorder, agoraphobia and separation anxiety. The rates for co-occurrence vary among the anxiety disorders.
PTSD is triggered by a traumatic event, which can also be the basis for the onset of BPD. Studies have shown that more than 50 percent of people with BPD also have a diagnosis of PTSD. Several symptoms of these two disorders can overlap, including poor emotional regulation and constant mood swings.
People with BPD may turn to drugs or alcohol to deal with stress and other symptoms of their disorder. Substance abuse, especially alcohol abuse, has a rate of co-occurrence with BPD of more than 30 percent, according to NIMH.
Eating disorders such as anorexia, bulimia and Binge Eating Disorder describe abnormal eating behaviors in which food is either over- or under-consumed, resulting in harm to an individual’s physical and mental health. According to NIMH, about 25 percent of people with BPD also have an eating disorder.
Awareness of these prevalent conditions co-occurring with BPD, and their potential to mask the underlying borderline condition, is essential for an accurate diagnosis and subsequent planning of an effective BPD treatment program.