14 DAY TRIAL // One of the most interesting symptoms associated with depression is called anhedonia, and its presence means that those affected are unable to experience pleasure. When it affects teen patients, the condition is caused by diminished levels of the neurotransmitter γ-Aminobutyric acid (GABA).
In a new study conducted on this population subgroup, investigators learned that a vital section of the brain – usually involved in regulating one's moods – was especially affected by this decrease in GABA levels. Details of the work appear in the latest issue of the journal Archives of General Psychiatry.
The investigation was funded by the National Institute of Mental Health (NIMH), which is a division of the US National Institutes of Health (NIH). According to official statistics, anhedonia accompanies depression in some 59 percent of cases in teens.
Arriving at this conclusion was rather difficult, since many of the depression symptoms teens exhibit can be confused for symptoms belonging to other conditions. In addition, there is no fixed set of indicators that doctors can look for, so they largely have to play by ear.
The new research was carried out by investigators at the New York University (NYU) School of Medicine, who were led by expert Vilma Gabbay, MD. The team decided to study the effects of GABA after analyzing similar studies carried out on adults.
GABA is very important in the human body. For example, it plays a vital role in regulating muscle tone, and is also responsible for controlling neural excitability throughout the human nervous system.
Thus far, the neurotransmitter has been linked to conditions as diverse as schizophrenia, postpartum depression, and learning disorders, but experts say that they are just getting started with studying the chemical, PsychCentral reports.
In the study, scientists analyzed 10 depressed teens with anhedonia and 10 that did not display the symptom. All participants were hooked to a functional Magnetic Resonance Imaging (fMRI) machine, so that researchers could observe GABA flow in their anterior cingulate cortex (ACC).
Results obtained in this manner were then cross-referenced to data from 21 test subjects who did not have depression or anhedonia. ACC GABA levels in the anhedonia group were found to be much lower than those in the depression group.
The NYU team says that a large-scale study now needs to be conducted on more teens, in order to confirm the new results. If they stand, then this information could be used to develop new approaches to treating anhedonia and, to some extent, depression.