The topic is sucide and suicidal ideation, and the pictures come from what I was reading this afternoon and what was emailed to me from a colleague. One of my habits is reading the JAMA psychiatry online first papers, and this picture and the quote relate to magnetic stimulation of the brain (MST) in a small population of people with treatment resistent depression (TRD).

I think neuroscientists like abbreviations as much as biochemists or the military. N100 and LIDI are two ways of measuring signal inhibition in the frontal cortex, GABA is gamma-Aminobutyric acid.

Suicidal ideation has been shown to be linked to hopelessness, negative affect, and attentional biases. These maladaptive behaviors all fall under the domain of negative valence systems and are associated with the specific constructs of loss, sustained threat, and frustrative nonreward. Suicidal ideation may represent a better phenotype through which to understand the neurobiologic features of mental illnesses. In this case, variations in GABAergic-mediated inhibition before MST treatment explained much of the variance for improvements in suicidal ideation across individuals with TRD.

There is also robust literature linking cortical inhibition to suicidal ideation. For example, previous studies have found abnormal GABAergic neurotransmission in suicidal patients, particularly in those with depression. Based on genetic and epigenetic studies, suicidal patients were shown to have decreased messenger RNA expression64 and increased DNA methylation65 of genes encoding the GABAA receptor in the frontal cortex. Moreover, messenger RNA expression of several genes related to the GABAA receptor is increased in depressed suicidal patients compared with nondepressed suicidal patients. It stands to reason that physiological measures that assess GABAergic neurotransmission can represent an important biological target through which treatment response can be predicted.

Now for the other two pictures. They are from a Lancet review article on suicide. The lancet article is quite worthwhile, but behind a paywall. The first shows how suicidal ideation and attempt and death are not the same in each country.

And the second is the current best attempt at modeling suicide, from the review. Each part of this makes clinical sense. Not each part has good data. And none of it will explain why this person is a victim, and not that person.

Those who start blaming parents, or society, or the mental health services: or the spouse, or lawyers, or the “gummint” miss something. Humans are complex. We are more than our brain: the mind is more than neural networks.

We have free will. And that modeling cannot account for.

But without that, we would not be accountable: to God, or to each other.