Readers of the Mental Elf will be aware that problematic drinking is a major issue in the UK; 24.2% of the UK population are classed as hazardous drinkers (8+ AUDIT scores) and 3.8% as harmful drinkers (16+ AUDIT scores). Two-thirds of harmful drinkers show symptoms of alcohol dependence (NICE 2011). Although alcohol misuse is a major problem in its own right, it is argued that alcohol misuse in combination with other mental illnesses may have especially poor outcomes.

One illness that may be particularly problematic when comorbid with alcohol misuse is Post Traumatic Stress Disorder (PTSD). Although the rates of comorbidity between PTSD and alcohol misuse are not as high as some disorders (e.g. anxiety and depression) this does not mean PTSD with alcohol misuse is not a major issue. Indeed, symptoms of each disorder may mask each other, outcomes may be poorer than for either illness in isolation, and alcohol misuse may sometimes be a consequence of PTSD.

The current review focuses on the comorbidity between PTSD and alcoholism with additional focus on whether particular symptoms of PTSD are associated with alcohol misuse.

Methods

The authors conducted a systematic review of research that investigated prevalence of both alcohol misuse and PTSD. There were stringent inclusion criteria (reflected in the estimated quality of studies reviewed), these included at least 100 participants, adult samples, standardized or clinically diagnosed PTSD and specific analysis of alcohol misuse (i.e. not as part of a broader measure of substance abuse).

42 studies met these criteria, with 31 scoring three or more for quality. The authors also classified studies as to whether participants were treatment seeking or non-treatment seeking. The association between alcohol misuse and the three symptom clusters of PTSD was also analysed.

PTSD symptom clusters

• Cluster B: Re-experiencing
• Cluster C: Avoidance and numbing
• Cluster D: Hyper arousal

Comorbidity rates were described separately for studies investigating populations that had:

1. Not previously been defined as suffering from PTSD or alcohol misuse
2. Been previously defined as having PTSD or
3. Been previously defined as having alcohol misuse

Results

• Populations not previously defined as having either disorder (N=2)
  • Prevalence from 15.9% to 25%
• Populations defined as having PTSD (N=15)
  • Prevalence 9.8% to 61.3%
• Populations defined as having alcohol misuse problems (N=14)
  • 2% to 60%
  • Most falling in 15% to 30% range
  • Military populations had the highest rates of co morbid PTSD with alcohol misuse
• Association between different PTSD symptom clusters and alcohol misuse (N=9) 
  • Cluster C symptoms were associated with alcohol misuse in all but one of these studies
  • Further exploration of cluster C symptomology found that there was a tendency for numbing to have a stronger association with alcohol misuse than avoidance
  • Cluster D symptoms were also found to be associated with alcohol misuse, although findings regarding cluster B symptoms were inconsistent.

Conclusions

This review highlights the association between PTSD and alcohol misuse suggesting at least 10% of those with PTSD also exhibit alcohol misuse, particularly in those exhibiting cluster C and D symptoms. Treatment seeking compared to not treatment seeking did not differ in severity of symptoms, but there was some evidence for a correlation between severity of alcohol misuse and PTSD.

The authors argue that this comorbidity is a major concern and that current NICE guidelines may not be sufficient for dealing with the problem as they state PTSD should not be dealt with unless alcohol dependence is first treated. The content of this review make it concerning that there are no specific guidelines for the treatment of comorbid PTSD and alcohol misuse.

Overall this paper does an excellent job of reviewing the data on comorbid PTSD and alcohol misuse. The summary table is extremely thorough and would be useful for clinicians or students. In the future, the elf would like to see a meta-analysis investigating comorbidity between alcohol misuse and PTSD with particular emphasis put on differences in prevalence in different groups, e.g. veterans, disaster survivors etc (such a meta-analysis could have political as well as medical implications).

Link

Debell F, Fear NT, Head M, Batt-Rawden S, Greenberg N, Wessely S, Goodwin L. A systematic review of the comorbidity between PTSD and alcohol misuse. Soc Psychiatry Psychiatr Epidemiol. 2014 Sep;49(9):1401-25. doi: 10.1007/s00127-014-0855-7. Epub 2014 Mar 19. [Abstract]