# Combination of Severe Depression and Antidepressant Use Impairs Driving Ability



## Halo (Aug 19, 2008)

Combination of Severe Depression and Antidepressant Use Impairs Driving Ability

August 19, 2008 (Boston, Massachusetts) ? A combination of severe depression and antidepressant use may impair driving ability, new research suggests.

In a study presented here at the American Psychological Association 116th Annual Convention, researchers from the University of North Dakota found individuals with severe depression who were taking antidepressants had reduced concentration and slower reaction times behind the wheel than their counterparts with milder depression who were also taking antidepressants.

Furthermore, study participants with mild depression who were taking antidepressants performed no differently from normal controls.

"These findings suggest that together, high depression scores and antidepressant use seem to confer a double whammy, so that individuals with this combination have significantly poorer concentration and slower reaction times when driving," principal investigator Holly Dannewitz, PhD, told Medscape Psychiatry.

*Conflicting Findings*

According to Dr. Dannewitz, a small number of previous studies suggest some antidepressants can negatively affect individuals' cognitive performance, impairing memory and reducing reaction time. However, she added, other studies suggest antidepressant treatment has no effect on cognitive function. 

To further explore the potential impact of these medications on cognitive function, and specifically driving performance, the researchers recruited 60 individuals ? 31 who were on at least 1 antidepressant and 29 matched controls who were taking no medication with the exception, in some cases, of oral contraceptives.

To determine depression levels and information about current medication use, all participants completed the Beck Depression Inventory, 2nd ed (BDI-II), a History of Sadness Questionnaire, and a medical history questionnaire.

Subjects in the antidepressant group were further divided into 2 groups, 1 with average BDI-II scores of 0 ? 12 and the other with above-average BDI-II scores of 14 ? 39. 

Study subjects participated in a computerized driving simulation to assess driving ability ? specifically, steering, scanning, and concentration. Following completion of practice laps, individuals completed 4 test laps. The practice lap was the easiest and the final lap the most difficult in terms of a greater number of distracters and the need for more responses.

The driving simulator measured reaction times for 2 tasks ? a peripheral and central task. The central task required subjects to hit the brake pedal in response to brake lights, while the peripheral task required participants to hit a paddle in response to a stop sign or traffic signal.

*Driving Ban Not Warranted*

Interestingly, said Dr. Dannewitz, there were no differences between any of the study groups in terms of their steering/tracking ability. However, the more "subtle" measures of reaction time were where individuals with high depression scores performed poorly.

Although patients with high depression scores who used antidepressant medications did worse than the other 2 study groups, Dr. Dannewitz said the impairment is not so severe that it would warrant a driving ban in such individuals. 

Nevertheless, she said, physicians with patients who fit this profile should be aware that their driving ability and other functions that require optimal concentration and quick reaction time may be impaired. 

Further research is warranted to tease out whether mood or medication use is the primary driver of this phenomenon or whether there may be a synergistic effect at play. It would also be useful, she said, to investigate different types of antidepressants to uncover potential differences between classes of antidepressant mediations or individual drugs. 

American Psychological Association 116th Annual Convention: Abstract I-11. Presented August 17, 2008.


----------



## Into The Light (Aug 20, 2008)

i didn't read this thoroughly but i think just severe depression impairs a person. i remember crossing a street and forgetting to even look if traffic was coming my way. that was without being on medication. i remember driving too and having a near miss.

with severe depression you are so sleep deprived and so exhausted.

i'm not convinced that the anti-depressants are the culprit here.


----------



## Halo (Aug 20, 2008)

From what I understand, the article is saying that the culprit is antidepressants alone but yet that the combination of severe depression together with antidepressants _could_ impair driving ability.

It is not the antidepressants only as indicated by this:



> Furthermore, study participants with mild depression who were taking antidepressants performed no differently from normal controls.


----------



## Daniel (Aug 20, 2008)

> There were no differences between any of the study groups in terms of their steering/tracking ability. However, the more "subtle" measures of reaction time were where individuals with high depression scores performed poorly.



I wonder if there is a do-it-yourself test for reaction time like playing a racing video game at home 

From an older article that Halo posted last year:



> Patients taking SSRIs and mirtazapine had better test performance than those who were taking tricyclics.
> 
> Antidepressants' Effects on Driving Ability - Psychlinks Psychology Self-Help  & Mental Health Support Forum


----------



## Halo (Aug 20, 2008)

I guess the bottom line on both articles ends up the same:



Halo said:


> Antidepressants' Effects on Driving Ability -- The researchers urged clinicians to stress to patients who are taking antidepressants the possible effects of their medication while driving.


 
and 



Halo said:


> Combination of Severe Depression and Antidepressant Use Impairs Driving Ability -- Nevertheless, she said, physicians with patients who fit this profile should be aware that their driving ability and other functions that require optimal concentration and quick reaction time may be impaired.


----------



## ladylore (Aug 20, 2008)

I know that taking Amatriptyline makes me drowsy. I take it at night but there are lasting effects throughout the day.


----------



## Into The Light (Aug 20, 2008)

but no one seems to be comparing mild depression with severe depression where people are not on any medication.

severe depression in and of itself impairs people's abilities and reaction time.

or is that so obvious it's not looked at?


----------



## Daniel (Aug 20, 2008)

Yeah, an article I saw at FOX News (and probably most articles about this study) also failed to discuss that point. 

I just went to the APA convention's website, and their press release is certainly the source of the confusion.   Fortunately, they also link to a US News article that shows some good journalism:



> *Antidepressant Use Tied to Poorer Driving*
> 
> *But experts aren't sure if the pills, or underlying depression, are to blame*
> 
> ...



BTW, from Florida's driver safety handbook (which is required reading for obtaining a Florida driver's license):



> Emotions can have a great effect on you driving safely. *You may not be able to drive well if you are overly worried, excited, afraid, angry or depressed*.
> 
> If you are angry or excited, give yourself time to cool off. If necessary take a short walk, but stay off the road until you have calmed down.
> 
> ...



I never thought listening to the radio could actually help, but I'm sure it is true in some cases, though in other cases it could be distracting in a bad way.


----------



## Halo (Aug 20, 2008)

Into The Light said:


> severe depression in and of itself impairs people's abilities and reaction time.



:agree:



Into The Light said:


> or is that so obvious it's not looked at?



Probably and I think that the use of medication was the focus point of the research more than the level of depression. Although the article that Daniel posted does indicate that a slightly different perception but clearer view, in my opinion.


----------

