Addictive Behaviours Post ABI

ABI and Substance Abuse

Several studies have examined the rates of substance abuse in those who have sustained a TBI and found that 44 to 79% of individuals have an alcohol addiction at time of injury, while another 12 to 33% reported having a drug addiction (Kolakowsky-Hayner et al. 2002; Taylor et al. 2003; West et al. 2009). The Diagnostic and Statistical Manual (DSM-IV-TR) outlines criteria that must be satisfied to determine if an individual has an addiction or dependence issue; however, the definitions of ‘abuse’ and ‘addiction’ vary between studies. A study examining the effects of alcohol and other substances on various neuropsychological measures found those who reported using alcohol or other substances prior to their injury, scored significantly lower than those who did not have a history of substance use (Kelly et al. 1997). It has been noted that of those who sustain their injury in a motor vehicle collision (one of the leading causes of TBIs), almost half were found to be intoxicated (DeLambo et al. 2008; Wehman et al. 2000; West et al. 2009). Acute intoxication has been found, in some studies, to impact the duration of coma, length of time in post-traumatic amnesia (PTA), overall length of stay, post recovery cognitive outcomes and self-care abilities (Bombardier & Thurber 1998; Vickery et al. 2008).

Studies have found that substance abuse issues occur more frequently with those who have sustained TBI then members of the general public (Taylor et al. 2003) and many will return to drinking within two years of injury (Bombardier & Thurber 1998). Hibbard et al. (1998) reported that as many as 40% of the TBI population meet the criteria for substance abuse or dependence as defined by the DSM-IV. Post injury, even small amounts of alcohol can result in more significant cognitive impairments as the individual works through the recovery process (Tweedly et al. 2012). The link between depression or other mood disorders and substance abuse has also been shown to be quite strong both pre and post ABI (Jorge & Starkstein 2005).

Individual Studies

Table: Prevalence of Substance Use and Abuse Pre and Post ABI

Discussion

There is currently a large variation in the rates of substance abuse reported in the TBI population; the studies listed above confirm this discrepancy. The prevalence of pre-injury alcohol abuse was reported between 11.5% and 49% (Andelic et al. 2010; Bombardier et al. 2002; Kwok et al. 2013; Ponsford et al. 2007) while illicit drug use was reported to be between 30% and 38% (Bombardier et al. 2002; Kwok et al. 2013). The problem with comparing the reported pre-injury substance abuse rates is that the inclusion criteria for many of the studies differ. Studies which only include subjects with a positive Blood Alcohol Concentration (BAC) at time of admission will report an inflated incidence since non-users are automatically excluded. Bombardier and colleagues (2002) reported that the number of drinks per week pre injury reported by their sample was in the 84th percentile of average American alcohol consumption. This suggests that substance abuse is a much greater problem in the TBI population than in the general population. Furthermore, a history of substance abuse may be a risk factor for future TBI. Interestingly, substance abuse is more often affiliated with moderate to severe injuries while intoxication at time of injury is more often affiliated with mild injuries (Andelic et al. 2010). Studies suggest that alcohol consumption and substance use decline within the first year of injury (Bombardier et al. 2003; Jorge 2005; Kelly et al. 1997; Ponsford et al. 2007), but those who returned to drinking two years post injury were likely to consume more than before the injury, drink excessively, and be dependent on alcohol (Bombardier et al. 2002; Ponsford et al. 2007). Ponsford and colleagues (2007) reported the same trend for the use of illicit drugs. TBI victims who abused alcohol pre-injury were 10 times more likely to demonstrate problematic alcohol use post injury (Bombardier et al. 2003).

Individual characteristics were also found to determine the likelihood that a patient with a TBI will have difficulties controlling their substance use. High consequences associated with drinking are thought to mediate the frequency of alcohol consumption and alcohol dependence (Turner et al. 2003). Individuals who drink excessively and have large negative consequences associated with their drinking are more likely to report alcohol as the cause of their TBI and are more likely to report pre-injury substance abuse (Turner et al. 2003).

 

 

Substance abuse and intoxication at time of injury is a frequent phenomenon in the traumatic brain injury population.

Substance addiction pre injury is predictive of substance addiction post injury.

 

Substance Abuse and Assessing the Severity of Injury

When assessing the severity of injury several issues have been raised. The first is the use of the Glasgow Coma Scale (GCS). It has been suggested that the GCS is unreliable when using it to establish functioning level at time of injury for those who have been drinking and/or using other substances (Jagger et al. 1984). However, Stuke et al. (2007) in a recent study found the GCS was not affected by the BAC of individuals admitted to a local trauma centre. This finding has been supported by some (Kelly et al. 1997; Sperry et al. 2006); and rejected by others (O'Phelan et al. 2008). To date there is conflicting evidence when looking at the effects of alcohol on the level of injury, survival rates and GCS.

Effect of Substance Use on Initial Assessments and Severity of Injury

Alcohol use has been identified as a contributing factor in the cause of brain injury but more destructively as a factor which promotes poor long-term recovery from injury and makes assessment of injury more difficult (Vickery et al. 2008). Recent evidence implies that alcohol has a neuroprotective effect on neuronal recovery post TBI (Andelic et al. 2010; Berry et al. 2010; Shahin et al. 2010). The evidence surrounding the effects of alcohol at time of injury is conflicting. 

Individual Studies

Table: Effects of Substance Use at Time of Injury on Severity of Injury Post ABI

Discussion

Several studies have investigated the effects of alcohol and/or other chemical substances on GCS, and length of stay in intensive care (Sperry et al. 2006; Vickery et al. 2008). It has been noted by Andelic and colleagues (2010), that patients diagnosed with a less severe TBI more frequently report substance use at the time of injury while those diagnosed with a more severe injury frequently report pre-injury substance abuse. Sperry et al. (2006) found no relationship between alcohol intoxication and GCS, nor did they find a linear relationship between BAC and GCS. However, a study found a higher BAC was associated with a better improvement in GCS over time (Shahin et al. 2010). Although it has been suggested that the presence of alcohol or other substances leads to a greater risk for poorer outcomes, evidence is still inconclusive.  

 

The impact that blood alcohol levels have on Glasgow Coma Scale, Injury Severity Score, mortality, and long term outcomes has yet to be determined.

                                                 

 

Effects of Substance Use on Mortality

The protective role of elevated levels of serum ethanol levels and TBI continues to be debated. Recent research suggests that alcohol acts as a neuroprotective agent and plays a role in survival post injury (Berry et al. 2010). Further, earlier studies have found that mortality was not more common in those who had been intoxicated at time of injury (Kelly 1995). Despite the quantity of studies looking at levels of intoxication, length of hospitalization, TBI severity and mortality, a solid link has not yet be made (Berry et al. 2010; Kelly et al. 1997).

Individual Studies

Table: Effect of Substance Use on Mortality Post ABI

Discussion

Over the past couple of decades several studies have investigated the effect of BAL on mortality post TBI. Tien et al. (2006) found that moderate or low BAC levels lowered the risk of dying in those who had sustained a severe TBI. Overall, study findings suggest elevated BAL is not associated with an increased risk of mortality post injury (Berry et al. 2010; O'Phelan et al. 2008; Salim et al. 2009; Shandro et al. 2009; Tien et al. 2006). Further, O’Phelan et al. (2008) looked at the effect of BAL, cannabis and amphetamines, and found that both alcohol and methamphetamine were associated with a decrease in mortality. Further research needs to be conducted to determine conclusively the effects alcohol and other substances have on severity of TBI.

 

Although alcohol and elevated blood alcohol levels have been linked to an increase risk of sustaining a TBI, there is evidence to suggest that elevated blood alcohol levels are not linked to an increase risk of mortality post injury.

The possible neuroprotective role acute alcohol intoxication plays in TBI warrants further investigation.

 

Post-injury Recovery and Substance Addiction

If individuals continue to use or abuse alcohol or drugs post injury, their recovery is negatively impacted. Continued use of alcohol or other substances may increase levels of aggressiveness, risk of seizures, decrease their satisfaction with life and increase family stress. Substance abuse often impacts the neurotransmitter process making it difficult to assess the impact that the brain injury has on the individual. Many individuals have been found to spend more time in rehabilitation programs, as alcohol addiction has been found to accentuate sensory motor, cognitive and communication problems post injury (Wehman et al. 2000). Continued involvement with alcohol and other substances increases the risk of developing medical complications.

Involvement in rehabilitation deters or prevents individuals from using various substances as patients are monitored rather closely (Bjork & Grant 2009). However, once patients are discharged from inpatient rehabilitation, no monitoring exists and patients may return to their previous behaviours or begin using drugs and alcohol as a coping strategy. Alcohol and other substance addictions may lead to a failure to survive independently in the community (Burke et al. 1988).

Individual Studies

Table: Influence of Substance Use or Abuse on Neuropsychological Outcomes Post-ABI

Discussion

Studies investigating the impact of substance use or abuse on neuropsychological outcomes post ABI have resulted in conflicting results. Schutte and Hanks (2010) found that BAL only predicted functional outcome at rehabilitation admission. BAL did not predict cognitive outcomes while age at time of injury was significantly associated with cognitive measures at one year follow-up. Comparatively, recent research with a smaller sample size found many cognitive measures to be associated with hazardous pre-injury drinking and age (Ponsford et al. 2013).

In an earlier study by Tate et al. (1999), BALs were predictive of poorer performance on a variety of neuropsychological measures during post-acute recovery. Overall study authors suggest an increase in BALs predicts greater cognitive impairment. Similar results were noted in a study conducted by Bombardier and Thurber (1998). Here BALs predicted poor performance on orientation tasks, concentration and mental speed, naming abilities, verbal memory and abstract reasoning. Wilde and colleagues (2004) also noted that an increase in alcohol abuse was associated with increased brain atrophy post injury. 

 

Earlier studies indicated that elevated blood alcohol levels are associated with poorer performance on a variety of cognitive communication tasks; however, these finding have generally not been supported in most recent studies.

Recent research has found age at injury to be negatively associated with cognitive outcome. More research needs to be conducted investigating the impact of alcohol on cognitive outcomes post injury.

 

Substance Abuse Treatment post ABI

Several theories have been put forth regarding the types of programs that might reduce substance abuse in the TBI population, but little research was found supporting these theories. A study was conducted by Corrigan and Bogner (2007) looking at using financial incentives to encourage those with a TBI and substance abuse problem to remain in treatment. In a systematic review, Corrigan and colleagues (2010) concluded that research focused on interventions for substance abuse specifically excluded participants with severe TBI. 

Individual Studies

Table: Compliance with Substance Addiction Treatment Programs Post ABI  

Discussion

Recently several studies have been conducted looking at the effect of motivational interviewing coupled with information sessions and the impact it had on patients returning to drinking post TBI (Ponsford et al. 2012; Sander et al. 2012; Tweedly et al. 2012). In two of these studies individuals were randomly assigned to an informal discussion group, an information group or an information plus brief motivational group. Participants were also stratified by gender (Ponsford et al. 2012; Tweedly et al. 2012). Results from each of these studies revealed that the intervention provided did not have a significant effect on drinking post injury or on willingness to change drinking habits. Sander et al. (2012) found those with a more severe injury expected alcohol use would negatively impact cognitive and physical impairments. Ponsford et al. (2012) noted that higher education and higher levels of depression were also associated with greater alcohol consumption.

In a study conducted in Corrigan and Bogner (2007), subjects with a diagnosed substance abuse problem were randomly assigned to one of three groups. All interventions were administered during a telephone interview. The three intervention groups were 1) provision of financial incentives to not miss appointments 2) reduction of logistical barriers to attending appointments and 3) attention control. Results demonstrated that offering a financial incentive (group 1) was more effective in promoting compliance in attending treatment sessions than either other intervention which aimed to reduce barriers. 

Conclusions

There is Level 2 evidence suggesting that neither education nor motivational interviewing has a significant impact on excessive alcohol consumption post-traumatic brain injury.  

There is Level 2 evidence supporting the use of financial incentives to encourage participants to continue with their substance addiction therapy following an acquired brain injury; however addressing the barriers preventing individuals from attending was not found to be successful. 

 

 

Education and motivational interviewing do not appear to have a strong impact on excessive alcohol consumption post-traumatic brain injury.

Providing financial incentives does encourage those with a traumatic brain injury and a substance addiction to attend treatment more so than offering solutions to other barriers.