DEAR DOCTOR K:
I suffer from depression. My doctor told me that depression can cause cognitive impairment. Antidepressants improve my mood — can they help improve my thinking skills as well?
Depression is more than long bouts of intense sadness. People who suffer from depression often also experience a loss of energy and interest in things they once enjoyed.
To get to your question, depression can also change your ability to think. It can impair your attention and memory, as well as your information processing and decision-making skills. It can impact your ability to adapt your goals and strategies to changing situations. And it can affect executive functioning, the ability to take all the steps to get something done.
It’s hard to answer your question without knowing if you feel your depression has caused thinking problems. That is, your doctor has told you depression can affect thinking in some people — but are you one of those people? I’m guessing you are, since you asked the question. So I did some homework.
I spoke to my colleague James Cartreine, an instructor in psychiatry at Harvard Medical School. He noted that medications can provide some relief of classic depression symptoms. But less is known about whether they can improve cognitive impairment related to depression.
Recently, researchers attempted to answer this question as part of a larger study on depression treatment. Their results were published in the journal The Lancet.
The researchers recruited more than 1,000 people with depression who were not taking medication. They were then randomly assigned to take one of three antidepressant drugs for eight weeks. The drugs were escitalopram (Lexapro), sertraline (Zoloft) or venlafaxine-XR (Effexor-XR). The participants went through extensive cognitive testing before and after treatment.
Of these patients, 95 percent showed no improvement on any of the cognitive impairments. And none of the three drugs was better than the others at improving cognitive symptoms. In other words, none of the medications helped improve thinking skills.
There are some limitations to this study. We don’t know if the participants had cognitive impairments before they developed depression. And the treatment period was short, only eight weeks.
Still, the results were not that surprising. Different parts and processes of the brain are responsible for cognitive and emotional functioning. What’s more, antidepressant medications are not designed to treat cognitive impairment. They’re designed to improve a person’s mood, and the ability to appreciate things and to have fun — qualities temporarily lost in many people with depression.
If antidepressants are unlikely to help with thinking problems that can accompany depression, it’s worth looking to non-drug solutions. Problem-solving treatment, for example, can teach people how to improve their problem-solving skills. And cognitive behavioral therapy can train people to recognize and challenge distorted thinking patterns. Another approach is cognitive remediation therapy, which uses practice drills to improve memory and executive function.
If you are having thinking problems, talk with your primary care doctor or psychiatrist about one of these options. They can be very effective.