Comorbidity of mental disorders and substance use: a brief guide for the primary care clinician
8.2 Comorbidity with personality disorders
People with personality disorders have:
- High rates of additional mental disorders(317).
- Higher rates of psychotic symptoms and psychotic disorders than controls and those with other mental disorders(316).
- Significant psychosocial impairment(312, 316).
- Higher rates of impulsivity compared with those who do not have a personality disorder(312, 316).
- Higher rates of suicidal ideation and suicidal behaviour than the general population(312, 316).
The term 'borderline' was first used to capture the features of the personality disorder that is borderline between psychosis and neurosis and characterised by extremes of mood and thinking.
Substance use is most common in those with Cluster B type personality disorder, in particular, borderline and antisocial personality disorder(120, 313, 318-320).
Conduct disorder in childhood (a necessary prerequisite to conclude that an adult has an antisocial personality disorder) is predictive of substance-use disorders between adolescence and early adulthood(320).
People with comorbid personality disorder and substance use:
- Have more problematic symptoms of substance use than those without a personality disorder(320).
- Are more likely to participate in risky substance-injecting practices that predispose them to blood borne viruses(312).
- Are more likely to engage in risky sexual practices(312) and other disinhibited behaviours.
- May have difficulty staying in treatment programs and complying with treatment plans(312, 316).
Treatment for substance use is also associated with a reduction in the likelihood of being arrested(313), suggesting a reduction in criminal activity.
8.2.1 General management approaches to comorbidity
- People with personality disorders are difficult to manage. Often, the underlying disorders will only become apparent after previous attempts to treat comorbidities have failed.
- People with personality disorders should be counselled about substance use and the problems that arise from substance use, given their particular personalities.
- However, many clients have difficulty even recognising that their substance use is problematic.