Seventy years ago, alcoholism was defined by the first edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM) as a type of sociopathic personality disturbance or more simply, a “personality disorder” (PD) (American Psychiatric Association, 1952; Newton-Howes & Foulds, 2018). While today PDs and alcohol-use disorders (AUDs) are understood to be separate constructs, there remains considerable evidence that they are related. Beyond their chronic and highly stigmatised nature, they share common causal risk factors, such as childhood abuse (Fergusson et al., 2013) which has been hypothesised to bring about a shared pathophysiology in the endogenous opioid system (Bandelow & Wedekind, 2015).

Guy et al. (2018) endeavour to quantify the relationship between PDs and AUDs in their article entitled ‘The prevalence of comorbid alcohol use disorder in the presence of personality disorder: Systematic review and explanatory modelling’.

Methods

The authors used a broad search strategy across Medline, Cochrane, Embase and PsycINFO databases from 1980 until 24 November 2015 as well as a hand search of the references in papers they cited.

Two authors independently extracted data and conducted quality assessments with a 5-item tool adapted from a Newcastle Ottowa design.

The primary outcome was the lifetime prevalence of any AUD among individuals with a PD and secondary outcomes included lifetime prevalence of alcohol dependence (AD), 12-month AUD prevalence and 12-month AD prevalence. Prevalence outcomes are non-normally distributed and so Freeman-Tukey transformations were applied.

Random effects meta-analysis models were then fitted with a multilevel framework to account for some studies reporting more than one type of PD. Heterogeneity was assessed using the I² statistic and by examining outcome variance within studies (τ² at level 2) and between studies (τ² at level 3). After model fitting, pooled prevalence estimates and confidence limits were calculated.

For lifetime AUD prevalence, the analysis was extended to include moderators such as sample type (clinical vs general population) and type of PD (antisocial (ASPD) vs borderline (BPD) vs other PD).

The contribution of these predictors was assessed by using the Bayesian Information Criterion to assess model fit and by comparing the total variance at levels 2 and 3 (τ²) in these models with the τ² in the original model with no predictors.

To assess for publication bias, the authors performed a univariate regression of lifetime AUD prevalence against its variance.

The authors performed a sensitivity analysis to determine the influence of excluding studies with special populations or those of low quality.

Results

The literature search generated 3,421 records. 293 were screened in full for eligibility and 20 were included in the quantitative synthesis.

All studies reported using DSM criteria to diagnose PDs and AUDs.

Thirteen articles (from 10 unique studies) reported Lifetime AUD prevalence. Since some articles reported outcomes for >1 type of PD, 16 outcomes in total were meta-analysed, giving a pooled estimate of 58.7% (95% CI: 46.4 to 70.6) for lifetime AUD prevalence among people with a PD.

When the type of PD reported was added to the model, the model fit improved and type of PD was found to be a statistically significant moderator (Q=20.9, df = 2, p<0.0001).

When dividing participants by PD type, lifetime AUD prevalence estimates were:

• Antisocial personality disorder (ASPD): 76.7% (95% CI: 65.7 to 86.1)
• Borderline personality disorder (BPD): 52.2% (95% CI: 41.6 to 62.5)
• Other (remaining types including combined and undifferentiated PD): 38.9% (95% CI: 28.9 to 49.4).

There was no evidence of a significant difference in lifetime AUD prevalence between the general population and clinical populations.

Eight articles (from 6 unique studies) reported lifetime AD prevalence. Three were in clinical populations, two in prisons and three studies reported on the United States Epidemiologic Survey of Alcohol and Related Conditions (NESARC).

In clinical and general population samples, lifetime AD prevalence estimates ranged from 21% to 47% (median 35%). Among prison samples, estimates of lifetime AD prevalence were considerably higher (45% to 97%). These estimates were not meta-analysed due to very high heterogeneity (I² = 98.5%).

Five papers from 4 unique studies measured 12-month AUD prevalence, which ranged from 12.9% to 31.1%. Outcomes were not meta-analysed due to heterogeneity (I² = 98.5%).

Four papers discussed 12-month AD prevalence. Three of these reported NESARC data and the fourth had only 11 participants, so these findings were not meta-analysed. Estimates of 12-month AD prevalence among the NESARC papers ranged from 12.9% in patients with obsessive compulsive PD to 31.1% in patients with BPD.

The assessment of bias demonstrated that smaller studies reported higher prevalence estimates. Authors reviewed studies with the highest figures and noted that these were reported in treatment seeking ASPD samples or in special populations. They then excluded both low quality studies and those in offender or indigenous populations and found a reduced estimate of lifetime AUD prevalence (49.6%; 95% CI: 34.7 to 64.6).

Conclusions

The authors concluded that their review:

demonstrates a very high lifetime prevalence of AUD among people with a PD.

They estimate that

approximately three quarters of people with antisocial PD and about half of those with borderline PD will experience an AUD at some point in the life course.

Strengths and limitations

While the nature of this analysis precludes the delineation of a causal pathway to explain why AUDs and PDs so commonly coexist, it is a robust addition to the evidence that the correlation between these types of disorder is significant and draws attention to the need to be clinically aware of how these disorders might interact.

The authors were able to make use of a number of trial designs and control for this statistically. However, they make note that 6 of the unique studies included in their review were rated ‘poor’ by their quality assessment, largely due to the use of highly specialised populations, such as prison inmates. They also note that lifetime prevalence figures are likely diminished due to recall bias. However, these limitations would likely result in underestimation of the comorbidity between AUDs and PDs, indicating that the real prevalence of AUDs in people with PDs may be higher than they have reported here.

The authors report a higher prevalence of AUDs in ASPD compared with BPD (76.7% vs 52.2% respectively). However, given that these are highly gendered diagnoses with up to 80% of antisocial PD being diagnosed in men and up to 80% of borderline PD being diagnosed in women, it is unclear whether the difference found by the authors is actually measuring differences between PDs or is simply recording the established differences in drinking behaviours between cisgender men and women (Bandelow & Wedekind, 2015; Beauchaine et al., 2009; Grant et al., 2015).

Implications for practice

The finding that AUDs (alcohol use disorders) and PDs (personality disorders) are highly comorbid has significant implications for how adult mental health and substance misuse services should be designed and delivered. The authors rightly note that the most obvious step to take is to thoroughly screen PD-presenting patients for AUDs, and vice versa. Perhaps more difficult is determining how to manage the comorbidity, which is associated with greater disability than either individual disorder.

Therapies do exist for comorbid substance-use and personality disorders, including dialectical behaviour therapy (DBT) (Linehan et al., 1999), dynamic deconstructive therapy (Gregory et al., 2008) and dual focus schema focused therapy (Ball et al., 2011). However, their results are variable and DBT, perhaps the most studied intervention for PDs has only been trialled specifically for AUDs once (Maffei et al., 2018). Further research is needed to determine the best course of action when these chronic, debilitating conditions present together.

Conflicts of interest

The author has no conflicts of interest to declare.

Links

Primary paper

Guy, N., Newton-Howes, G., Ford, H., Williman, J., & Foulds, J. (2018). The prevalence of comorbid alcohol use disorder in the presence of personality disorder: Systematic review and explanatory modelling. Personality and Mental Health, 12(3), 216–228. https://doi.org/10.1002/pmh.1415

Other references

American Psychiatric Association. (1952). Diagnostic and Statistical Manual of Mental Disorders. American Psychiatric Association. https://doi.org/10.1176/appi.books.9780890425596

Ball, S. A., Maccarelli, L. M., LaPaglia, D. M., & Ostrowski, M. J. (2011). Randomized Trial of Dual-Focused Vs. Single-Focused Individual Therapy for Personality Disorders and Substance Dependence. The Journal of Nervous and Mental Disease, 199(5), 319–328. https://doi.org/10.1097/NMD.0b013e3182174e6f

Bandelow, B., & Wedekind, D. (2015). Possible role of a dysregulation of the endogenous opioid system in antisocial personality disorder. Human Psychopharmacology: Clinical and Experimental, 30(6), 393–415. https://doi.org/10.1002/hup.2497

Beauchaine, T. P., Klein, D. N., Crowell, S. E., Derbidge, C., & Gatzke-Kopp, L. (2009). Multifinality in the development of personality disorders: A Biology × Sex × Environment interaction model of antisocial and borderline traits. Development and Psychopathology, 21(3), 735–770. https://doi.org/10.1017/S0954579409000418

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Gregory, R. J., Chlebowski, S., Kang, D., Remen, A. L., Soderberg, M. G., Stepkovitch, J., & Virk, S. (2008). A controlled trial of psychodynamic psychotherapy for co-occurring borderline personality disorder and alcohol use disorder. Psychotherapy: Theory, Research, Practice, Training, 45(1), 28–41. https://doi.org/10.1037/0033-3204.45.1.28

Linehan, M. M., Schmidt, H., Dimeff, L. A., Craft, J. C., Kanter, J., & Comtois, K. A. (1999). Dialectical behavior therapy for patients with borderline personality disorder and drug-dependence. The American Journal on Addictions, 8(4), 279–292. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/10598211

Maffei, C., Cavicchioli, M., Movalli, M., Cavallaro, R., & Fossati, A. (2018). Dialectical Behavior Therapy Skills Training in Alcohol Dependence Treatment: Findings Based on an Open Trial. Substance Use & Misuse, 53(14), 2368–2385. https://doi.org/10.1080/10826084.2018.1480035

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