Borderline Personality Disorder and Substance Use

A great deal of research has been conducted on the relationship between psychiatric disorders and substance use disorders. One extensive study collected data from the National Comorbidity Survey Replication. Researchers found that having any psychiatric disorder increases the risk for substance dependence. In fact, they found that as the number of psychiatric disorders present increased, so too did the risk for substance dependence. In other words, having any psychiatric disorder increases the risk for a lifetime of substance dependence.

Different psychiatric disorders have different risk levels, so the level of risk for substance abuse is not equal among the disorders in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV). For example, personality disorders carry a greater risk than either mood or anxiety disorders.

Borderline personality disorder (BPD) is highly comorbid with substance use disorders, but few theoretical explanations exist to explain the pattern of co-occurrence. In the United States, BPD affects 5.9 percent of the general population. As Cacciola, et al., stated, “All of the personality disorders have been reported in patients with substance abuse, with antisocial personality generally being the most prevalent; borderline personality is typically the second most prevalent.”

BPD is characterized by a lack of control over impulses, anger and intense emotions. Interpersonal relationships may be impaired and self-image disturbed. BPD is the most prevalent personality disorder being treated in both outpatient and inpatient settings. Understanding and properly treating this disorder is vital because the rate of suicide for those with BPD is estimated to be around 7%, and BPD is a risk factor for suicidal behavior.

A review was recently published in the medical journal Clinical Psychology Review that confirmed the comorbidity of substance use disorders and BPD for multiple substances of use or dependence. The researchers found that 14.3% of those with alcohol abuse or dependence met the criteria for BPD, 16.8% of those dependent on cocaine received a diagnosis of BPD, and 18.5% of those who abused opioids met the criteria for BPD as well. However, some studies have noted that the averaged percentage of substance use is as high as 44.3 percent.

In other words, nearly half of those with BPD have histories of substance use disorder. Rates of current and lifetime substance use vary from 14 to 72 percent. Other researchers have found a lifetime comorbidity rate of substance use disorder and BPD of 63.5 percent. This data demonstrates a clear relationship between substance use disorders and borderline personality. Interestingly, the findings were consistent regardless of whether these were inpatients, outpatients or participants in community settings.

One major issue for those trying to discern the relationship between these two disorders is that substance use can add to problems inherent in BPD such as affective instability, impulsivity and interpersonal problems. Some believe that the overlap between the diagnoses for BPD and substance use disorders is related to impulsivity in the criteria for BPD.

Age is related to both BPD and substance use disorders, in that younger people have higher rates of comorbidity than the general population. It is important to note that age is not considered causal for either disorder. Childhood trauma has been a common variable that is etiologically important in the genesis of both BPD and substance use disorder. When viewed this way, the two disorders may occur frequently together because they share risk factors.

Studies of BPD and comorbid Axis I diagnoses have found that substance abuse is more common in men with BPD than in women. Men with BPD also have a higher rate of alcohol dependence than women. Similar studies conducted with populations of inpatients found that substance use disorders were more common in male inpatients than female inpatients with BPD. This co-occurring disorder may contribute to the under-diagnosis and lack of treatment utilization among men with BPD.

Some theorize that men with BPD are more likely to end up in prison settings whereas women more frequently wind up in mental health settings for treatment. Others debate this finding, pointing to the possibility that men are over-represented in samples of substance use disorders and BPD because they experience more severe substance use issues than women.

One study published in 2010 on prescription drug abuse and BPD found that the rate of self-reported prescription drug abuse was 9.2 percent. Patients who abused prescriptions were more likely to have borderline personality. One study containing a large psychiatric sample found the rate of prescription substance abuse to be as high as 46.9 percent in patients with BPD. In these studies, the prevalence between the genders was roughly equal, unlike the rates for alcohol abuse.

Another explanation is that substance use disorders lead to BPD, or vice versa. For example, chronic drug abuse may lead to depletion of serotonin, which in turn might lead to self-destructive and impulsive behaviors. Those individuals who are neurobiologically vulnerable to BPD may be more susceptible to the effects of substance abuse.

Men are more likely to have co-occurring paranoid, passive-aggressive, narcissistic, sadistic and antisocial personality disorders than females. In other words, men with BPD can be characterized by antisocial overtones, which also correlates to the higher prevalence of co-occurring substance use disorders.

Some researchers note that the loss of important relationships and other life stressors brought upon by substance abuse may lead to BPD in vulnerable populations. Others hold that individuals with BPD may turn to psychoactive substances to self-medicate. The self-medication hypothesis is a psychoanalytically informed theory of drug addiction. This means that it includes the emotional and psychological dimensions in viewing addiction as a compensatory means to modulate effects from stressful states that are unmanageable for an individual.

According to this hypothesis, substance users experience emotions that are overwhelming so they use drugs to regulate emotions and achieve stability. The self-medication hypothesis considers the effects of drugs such as opiates, cocaine or alcohol as they interact with inner states. Given that these three drugs are the most frequently abused in BPD populations with comorbid substance use disorders, this theory deserves further examination.

For example, opiates in natural or synthetic form reduce pain. As previously mentioned, 18.5% of those with BPD abuse opiates. According to the self-medication hypothesis, those who have trouble managing rage or aggression often have been exposed to violence and aggression earlier in life. Proponents of this theory hold that opiate abuse is an adaptive function that mutes the rage or aggression experienced by the drug user.

Cocaine, on the other hand, elevates mood, increases one’s sense of confidence, and provides a feeling of improved mental performance, decrease in fatigue, and increased energy and productivity. In the study noted earlier, some 16.8% of those dependent on cocaine received a diagnosis of BPD.

Researchers have noted two types of cocaine users: low energy and high energy. The low energy users feel bored, empty and fatigued. The high energy users desire elated sensations. Cocaine users, in general, desire to rid themselves of feelings of emptiness, boredom, depressive states or restlessness.

Alcohol is the most widely abused substance in the United States, and among those with BPD 14.3% abuse alcohol. Alcohol is a central nervous system depressant, which means that it relaxes and sedates those who use it. According to the self-medication hypothesis, those who abuse alcohol often have rigid, constricted emotions. They avoid distress by cutting off emotions through these rigid defenses, resulting in disaffected states. The use of alcohol softens this defensive structure and allows people to relieve constricted emotions.

There is a clear connection between substance use disorders and psychiatric disorders, in particular personality disorders and BPD. While the rate of comorbidity ranges from 14 to 72 percent, this variance can be explained by the discrepancy between current and lifetime use. The rate is lowest for current substance use and highest for lifetime substance use among those with the disorder. While general substance use is alarming itself, prescription substance abuse is also an issue of concern for clinicians treating BPD. An awareness of the relationship between these issues may help family and mental health clinicians guide the proper treatment for patients suffering with this personality disorder.