Millions of people around the world suffer from depression, the most common mental disorder of all. Since depression appears to be largely genetic, several long-standing questions continue to bedevil researchers. Have the genes for clinical unipolar depression undergone selective evolution–or is depression a random product of mutation, evolutionary drift, or other non-selective forces?

The symptoms of depression are found in every culture and time period, from the ancient Greeks to modern New Yorkers, from the !Kung of southern Africa to ranchers in the American West. Why is depression so much more common than any other major mental illness? Clearly, it is a malfunction, a maladaptation — or is it? Read more →

In “The Origin of Consciousness in the Breakdown of the Bicameral Mind,” Julian Jaynes suggested back in 1976 that schizophrenia — like spirit possession and imaginary playmates — was a vestige of our brain’s bicameral heritage. Jaynes believed that in man’s early history, the left and right hemispheres of the brain did not “talk” to each other. They failed to communicate effectively across the corpus callosum, the bridge from one hemisphere to another. The result was, to Jaynes, obvious: People used to hear voices. Nowadays, most people who hear voices inside their head are diagnosed as schizophrenics. Read more →

For health care workers in psychiatric hospitals, it is no secret: one of the major issues confronting psychiatric facilities seeking to institute blanket no-smoking policies concerns chronic inpatients with schizophrenia. Patients with schizophrenia are almost always heavy cigarette smokers, given a choice. As Edward Lyon wrote in an analysis of studies and surveys performed throughout the 1990s: “Many patients in psychiatric hospitals would smoke two, three, or even four packs of cigarettes a day if an unlimited supply of cigarettes were available.” Read more →

There are now several clinical trials showing that mice and dogs show evidence of cannabis withdrawal. (For THC-addicted dogs, it is the abnormal number of wet-dog shakes that give them away.) Today, scientists have a much better picture of the jobs performed by anandamide, the body’s own form of THC. This knowledge helps explain a wide range of THC withdrawal symptoms. Read more →

In the past few years, as addiction researchers have been mapping out the chemical alterations in the brain caused by alcohol, nicotine, methamphetamine, and other drugs, America’s most popular illegal drug has remained largely a scientific mystery. It is a drug that millions of Americans have been using regularly for years, and, from a clinical perspective, it remains the least studied illicit drug of all.

The most popular, and the least studied — not a prescription for rational decision making from a public health point of view. A variety of influences combined to force marijuana research off the table years ago, but the birth of “receptorology,” as molecular scientist Candace Pert once called it, and a more relaxed grip on federal funding has refueled the research. Read more →

The science of neurology has created a paradigm shift in our basic understanding of the structure of the brain and the rest of the human nervous system. It has taken a long time, and a large group of doctors, clinicians and assorted scientists to piece together the ways in which this new knowledge of the brain has direct application to the states of mind and body we call addiction, alcoholism, or drug dependence.

When I first began following the subject of addiction in the early 1990s, the addiction field was still small, the insights highly tentative. However, what I had originally viewed as a series of potential breakthroughs in addiction research very rapidly became the tip of an enormous iceberg: brain science, and the revolutionary new directions represented by modern biology. Read more →