Depression

Brain stimulation offers hope for depression

By Kerrie-Anne Ho and Colleen Loo

Around 350 million people worldwide have depression. Antidepressant medications are often prescribed to treat the condition, alongside talking therapies and lifestyle changes such as regular exercise.

But a substantial proportion of people either don’t respond to antidepressants, or experience such significant side effects that they’d prefer not to take them.

In search of alternative solutions, researchers around the world, including our team, are investigating transcranial direct current stimulation (TDCS) as an alternative treatment for depression. But this isn’t something you can safely try at home.

Unlike electroconvulsive therapy, TDCS uses very mild electric current to stimulate the brain and has few side effects. The mechanics of TDCS are quite simple, involving a battery, two leads and the electrodes through which the current is passed.

Researchers are yet to fully understand the effects of varying stimulation approaches.
Tinydevil/Shutterstock

The stimulation works by changing the activity of nerve cells in the brain. In depression, the left frontal areas of the brain are often less active than usual. TDCS stimulates this area to restore brain activity.

We’re still evaluating the effectiveness of TDCS, but so far studies have found that TDCS works better than a placebo (or simulated treatment) at reducing symptoms of depression.

When combined with the antidepressant medication sertraline (marketed as Zoloft in Australia), the combination TDCS-drug therapy works better than medication or TDCS alone.

Research has found that among people with depression, a course of TDCS can improve the brain’s “neuroplasticity”, which is the brain’s ability to learn and adapt to changes in the environment.

The therapy has a good safety profile – if administered by clinicians and researchers trained in stimulation technique and safety. Our research team has administered thousands of TDCS sessions without incident.

But this is not the case when TDCS is used in the “DIY” context, with DIY users trying to stimulate their own brains.

This phenomenon is often guided by online forums and websites dedicated to DIY TDCS. Users comment on their own experience and share tips on how TDCS can be used to treat their own depression. People with no medical training and limited understanding of TDCS self-treat their depression and advise others on treatment.

Stronger is not necessarily better.
Ian Ruotsala/Flickr, CC BY-NC-SA

So, what can go wrong?

The most obvious concern is that poor technique and improper electrode placement could cause skin burns.

What’s more concerning is the ability for TDCS to produce lasting changes in brain functioning. Depending on how TDCS is given, these changes could be good or bad.

A DIY user could, for example, cause lasting impairment to their thinking and memory. For people with severe depression, incorrect application could worsen their condition or induce a hypomanic (manic) episode.

When it comes to medications, it’s important to get the right dose and dosing schedule. That’s why this role falls to qualified clinicians and researchers. The same goes for TDCS: current intensity, electrode size and position, and the duration and frequency of the stimulation determine the effects in the brain.

The relationship between dosing, intensity and position is highly complex. This isn’t a simple case of “the stronger the better”. Even researchers are yet to fully understand the effects of varying stimulation approaches and much more research is needed.

As with other forms of treatment, TDCS is not suitable for everyone. In clinical research trials, participants are screened for suitability to receive stimulation and their likelihood of responding to treatment. The stimulation is carefully controlled and the participants’ mood is carefully monitored during and after the course of treatment.

A substantial proportion of people don’t respond to antidepressants, or experience significant side effects.
Divine Harvester/Flickr, CC BY-NC-SA

TDCS represents a promising future, where simple and cost-effective treatment for depression is possible, without drugs. Researchers worldwide are continuing to study this experimental treatment, which may one day become a conventional treatment for depression.

The acceptance and popularity of TDCS among the general community is encouraging. But TDCS is still experimental and isn’t safe to administer at home. DIY users are not trained in proper technique nor are they trained to identify, prevent or deal with unexpected outcomes.

If you’re interested in participating in our TDCS trials for depression, contact the research team at the Black Dog Institute for more information.

The Conversation

This article was originally published on The Conversation.
Read the original article.

Could depression be caused by a virus?

depressed woman

© iStockphoto

Dr. Turhan Canli, associate professor of integrative neuroscience at Stony Brook University, makes a case for reconceptualizing depression as an infectious disease caused by foreign invaders like parasites, bacteria or viruses that make their way into the body and cause changes in the brain.

The Huffington Post spoke to Canli about his theory and what it might mean for future treatment.

Link here to read Why This Psychologist Thinks Depression Is An Infectious Disease

Zinc-PillsA meta-analysis of studies measuring blood concentrations of zinc in some 1,600 depressed subjects and 800 control subjects has found that zinc concentrations were significantly lower in the patients with depression. And in the studies that measured depressive symptoms, greater depression severity was associated with a greater relative zinc deficiency. The senior researcher was Krista Lanctot, Ph.D., of the University of Toronto, and results are published in Biological Psychiatry.

What the results mean from a clinical viewpoint, however, remains to be determined, the researchers point out. Since the literature on zinc and depression is largely limited to case-control and cross-sectional studies, it is not known whether depression creates a zinc deficiency or a zinc deficiency helps set the stage for depression. Zinc is an essential nutrient with multiple biological functions.

It is possible that depression creates a zinc deficiency, the researchers suggest, since appetite changes are a common component of major depression. One study of subjects with the disorder identified trends between lower zinc concentrations and weight loss and anorexia symptoms. On the other hand, a zinc deficiency can induce depressive-like behaviors in animals, which in turn can be reversed by zinc supplements, the researchers point out. Thus “the potential benefits of zinc supplementation in depressed patients warrant further investigation,” they note.

A wide variety of foods contain zinc. Oysters contain more zinc per serving than any other food, but red meat and poultry provide the majority of zinc in the American diet. Other good food sources include beans, nuts, certain types of seafood (such as crab and lobster), whole grains, fortified breakfast cereals, and dairy products.

A comprehensive overview of depression and how to offer optimal care to depressed patients can be found in the new American Psychiatric Publishing book, Clinical Guide to Depression and Bipolar Disorder: Findings From the Collaborative Depression Study. For more on treating depression, see Treatment-Resistant Depression: A Roadmap for Effective Care.

American Psychiatric Association

depressed womanLow-dose intravenous infusions of ketamine, a general anesthetic used in minor surgeries, given over a long period are an effective treatment for depression, Mayo Clinic researchers found. The study is published in the Journal of Psychopharmacology.

About a decade ago researchers discovered that ketamine had the potential to alleviate severe depression. However, ketamine also can have serious psychiatric side effects, so studies have been exploring the safest way to use it.

“It’s surprising both that it works and how rapidly it has effects,” says co-author Timothy Lineberry, M.D., a Mayo Clinic psychiatrist. “It sometimes can work in hours to reduce depressive symptoms and suicidal ideation. Our goal is to begin to determine how the drug can be administered safely in routine treatment.”

The researchers studied 10 patients with a severe depressive episode, either a major depressive disorder or a type of bipolar disorder, who had not found relief with at least two anti-depressant medications. The study shows that when ketamine infusions were given at the lower rate, they work as well as they do at higher infusion rates.

In the trial, patients were treated up to twice a week, up to four total treatments, with low-dose ketamine infusions (0.5 mg/kg total dose) given over 100 minutes until their depression lifted.

Researchers monitored side effects with two psychiatric scales, the Young Mania Rating Scale and the Brief Psychiatric Rating Scale. Eight of 10 patients showed at least 50 percent improvement. Five patients experienced complete remission of their depression, and four weeks after the study, two were still depression free.

In terms of side effects, one patient had brief and limited hallucinations, but others experienced only drowsiness or dizziness during the infusions.

One significant question that must still be addressed is determining which patients will respond best to the treatment.

“While patients and clinicians are excited about ketamine’s potential, we know that much more research lies ahead before we know which depressive conditions can be addressed with ketamine safely by clinicians in routine clinical practice,” Dr. Lineberry says.

Mayo Clinic