I've added the following text to "The Limbic System: Seat of Consciousness and Emotions in the Human Brain" by Vexen Crabtree (1998):

Over-activation of the limbic system can result in depression as well as religious phenomenon. In the case of depression, symptoms can be removed by medicating with drugs that affect certain parts of the limbic system, in particular through quantitively altering the action of certain neurotransmitters.

“Because of its relevance to the so-called vegetative symptoms of depression, such as disturbances in appetite and sleep, the hypothalamic - pituitary - adrenocortical axis is thought to be overactive in depression. Various findings support this proposition.”
"Abnormal Psychology" by Davison & Neale, p242


On the same subject but on a different page, I've also added the following to "The Soul and Emotions (The Biological Basis of Our Emotions): Depression and Mood Disorders" by Vexen Crabtree (1999):


Serotonin and norepinephrine are both related to our mood, and their flow causes changes in mood. So, antidepressants such as tricyclics and monoamine oxidase inhibitors increase the effect of certain neurotransmitters, and thereby raise the mood. Panic and mood disorders are inheritable6. This means, before a person is even conscious, they are predisposed to a neurotransmitter dysfunction that causes certain moods and even some mental disorders. When these symptoms become serious, depression can be lifted by the correct medication. All this shows that if there is a soul, it is unnecessary for the feelings of happiness, sadness, depress, etc, and that these things can even be beyond our control at all.

“Three major categories of antidepressant drugs:
Tricyclics, such as imipramine (Tofranil) and amitriptyline (Elavil);
Selective serotonin reuptake inhibitors, such as fluoxetine (Prozac); and
Monoamine oxidase (MAO) inhibitors, such as Parnate. [...]
Tricyclic drugs are a group of antidepressant medications [that] prevent some of the reuptake of both norepinephrine and serotonin by the presynaptic neuron after it has fired, leaving more of the neurotransmitter in the synapse so that transmission of the next nerve impulse is made easier. [...]

All three types of drugs are believed to work by facilitating neural transmission. [...] People with the mood swings of bipolar disorder are often helped by carefully monitored dosages of lithium, an element, taken in a salt form, lithium carbonate.”
"Abnormal Psychology" by Davison & Neale, p240, 246-7

I've added the following quote to "Cultural Religion Versus Scholarly Religion" by Vexen Crabtree (2005):

“The religious professionals in each religion will usually look down upon the manifestations of popular religion. They will often refer to them as a corruption of the true religion or as evidence of the ignorance or sinfulness of the mass of the people. The truth is somewhat more complex than this. Popular religious practices fill some of the needs felt by ordinary people - needs that the official religion ignores. Thus, for example, most varieties of official religion disapprove of, or even forbid, recourse to talismans, spells, charms and other forms of magic. They are also against necromancy, astrology and other occult practices. Yet, in almost every society, these elements can be found in popular religion. [...] People regard these popular elements as an integral part of the religion and they are thought to derive their power and efficacy through the spiritual forces of the religion. For example, in most Muslim countries, amulets are worn as a magical protection against danger. These amulets usually contain verses from the Qur'an, which is considered to be the source of their power. Such practices persist despite the prohibition against them in the official religion.”

"The Phenomenon Of Religion" by M. Momen [Book Review], p387-389</p>

And added another short paragraph of my own:

"Theologians will tend to take the side of the 'professionals', and stick to the more formal, written, codified forms of religion. They will consider other elements, not discussed in literature, to be anomolies, sinful, and mistaken. Anthropologists will, more usefully, examine the actual practices of the people on the ground, and will therefore sometimes report that a religion of a local area is one thing, while theologians say it is another."