Clinical Challenges in Co-occurring Borderline Personality and Substance Use Disorders

Borderline personality disorder (BPD) is a serious illness involving multiple symptoms and mal adaptive behaviors. According to DSM-IV, "the essential feature of borderline personality disorder is a pervasive pattern of instability of interpersonal relationships, self-image, and affects" (p. 650). This pervasive pattern of instability also applies to behaviors that are impulsive and potentially damaging, including excessive spending, sexual promiscuity, reckless driving, binge eating, and substance misuse.^1,2

Substance misuse associated with BPD is often frequent and severe enough to warrant a separate diagnosis. As the Figure illustrates, about 50% to 70% of psychiatric in patients with BPD also have a substance use disorder (SUD), especially alcohol(Drug information on alcohol) abuse or dependence but often in combination with other drugs.^1,2

Depending on the sample, structured diagnostic interviews have found a variable prevalence of BPD among patients being treated for drug or alcohol dependence. The reported prevalence of BPD has ranged from 18% to 34% in patients receiving treatment for cocaine dependence.^3-5 In large samples of patients treated for opiate dependence, rates of co-occurring BPD have varied from 5% to 45%.^6-9 Among persons in treatment for alcohol use disorders, the prevalence of BPD appears similar to that for those in treatment for drug dependence, ranging from 16% to 22%.^10,11

Co-occurrence worsens course
There is evidence that co-occurring BPD worsens the outcome of alcohol and drug rehabilitation. In the study by Marlowe and colleagues⁴ of persons dependent on cocaine, BPD was the only Axis II disorder diagnosis that was consistently associated with a negative outcome, including measures of both treatment compliance and abstinence, and this relationship was in dependent of measures of anxiety, depression, or initial severity of drug dependence. Cacciola and colleagues6 examined 7-month outcomes of 197 men admitted to a methadone(Drug information on methadone) clinic. In that study, BPD had no significant effect on drug use, but it was associated with negative outcomes on other measures, including alcohol use, medical and psychiatric symptoms, and social relationships.

There is also evidence that BPD worsens the severity or course of alcohol use disorders. In a retrospective study by Martinez-Raga and colleagues,¹² patients at a detoxification program who had BPD or antisocial personality disorder were significantly more likely to have an unplanned discharge from the facility than those who did not have those personality disorder diagnoses. In the previously cited study by Morgenstern and colleagues,¹¹ co-occurring BPD predicted lifetime severity of alcohol dependence, psychological problems re lated to drinking, earlier age at onset of drinking, worse adaptive coping, and suicidal ideation, even after controlling for the effects of gender and concurrent Axis I disorders.

Likewise, studies examining patient populations in treatment for BPD have demonstrated that co-occurring SUD adversely affects outcome on measures of psychopathology. According to Miller and colleagues,¹³ BPD complicated by an alcohol use disorder is associated with unemployment, poor school performance, and promiscuity, com pared with BPD without a co-occurring alcohol use disorder. In their 2001 study, van den Bosch and coauthors¹⁴ compared 29 patients who had BPD with 35 patients who had co-occurring BPD and SUD. The latter group was found to have greater levels of anxiety, antisocial behavior, and suicide attempts. In a large psychological autopsy study of substance-related suicides, female victims were noted to have had high rates of BPD.¹⁵ Ryle and Golyn kina¹⁶ reported that cognitive analytic therapy for BPD was less effective for those patients with co-occurring alcohol abuse. However, a post hoc analysis of a randomized trial of dialectical behavior therapy (DBT) indicated that the presence of a co-occurring SUD was not a significant determinant of improvement in psychopathology.¹⁷

In a large prospective study of 290 subjects with diagnosed BPD who had been hospitalized at McLean Hospital in Belmont, Mass, Zanarini and associates2 reported that co-occurring SUD strongly and negatively correlated with remission from BPD at 6-year follow-up. The presence of SUD had a greater effect on outcome than did the presence of any other co-occurring Axis I disorder, including posttraumatic stress disorder, bipolar disorder, eating dis orders, or major depressive disorder. In their discussion, the authors stressed the need for the development of treatments that specifically target persons who have co-occurring BPD and SUD.

Possible mechanisms
It is not clear why so many patients with BPD also have SUD and why this combination is so detrimental. Do patients with BPD misuse substances simply because they are impulsive? Indeed, research studies have demonstrated a correlation between substance use and measures of impulsivity and affective lability in this population.¹⁸ However, patients sometimes describe their substance use as a mal adaptive coping mechanism. In the words of one patient, "You feel like a big shot when you're on cocaine, like you're important and in control and nothing else matters." Other patients note a calming effect from substances: "I feel like drinking after our sessions because we touch on a lot of things I've been trying to cover up, or hide, or not feel. So when I leave here, I have all kinds of feelings going on that I’m now going through. The drinking calms me down or lets me focus on something else."

Some intriguing neurobiologic research suggests that substance use in some persons can serve as a substitute for unmet attachment needs. In large prospective studies in Denmark, early weaning from breast-feeding has been associated with the development of alcoholism in adulthood.^19,20 These findings are similar to findings in animal studies. Barr and colleagues²¹ found that macaque monkeys separated from their mothers developed higher levels of ethanol preference. In addition, Moles and coinvestigators²² reported that mice that were lacking the µ-opioid receptor gene displayed both reduced reward dependence to nonopioid drugs of abuse and reduced attachment be haviors to ward their mothers. Satisfaction of unmet attachment needs may make substances particularly attractive to patients with BPD, who may otherwise exhibit pathologic interpersonal dependency.