Mostly downloaded from the NIMH brainstorming groups:
SUB-CATEGORIES OF THE FEAR DOMAIN
Responses to acute threat (Fear): Activation of the brain’s defensive motivational system to promote behaviors that protect the organism from perceived danger. Normal fear involves a pattern of adaptive responses to conditioned or unconditioned threat stimuli (exteroceptive or interoceptive). Fear can involve internal representations and cognitive processing, and can be modulated by a variety of factors.
Responses to potential harm (Anxiety): Activation of a brain system in which harm may potentially occur but is distant, ambiguous, or low/uncertain in probability, characterized by a pattern of responses such as enhanced risk assessment (vigilance). These responses to low imminence threats are qualitatively different than the high imminence threat behaviors that characterize fear.
Responses to sustained threat (Stress): An aversive emotional state caused by prolonged (i.e., weeks to months) exposure to internal and/or external condition(s), state(s), or stimuli that are adaptive to escape or avoid. The exposure may be actual or anticipated; the changes in affect, cognition, physiology, and behavior caused by sustained threat persist in the absence of the threat, and can be differentiated from those changes evoked by acute threat.
Frustrative non-reward: Reactions elicited in response to withdrawal/prevention of reward, i.e., by the inability to obtain positive rewards following repeated or sustained efforts.
Loss: A state of deprivation of a motivationally significant con-specific, object, or situation. Loss may be social or non-social and may include permanent or sustained loss of shelter, behavioral control, status, loved ones, or relationships. The response to loss may be episodic (e.g., grief) or sustained.
Distinctions among Constructs:
Acute threat (a tiger) is distinguished from potential harm by the immediacy and imminence of threat. Acute threat is considered to be a situation where the threat of harm is immediately present.
Potential harm (walking in jungle), by contrast, is regarded as involving situations where danger might occur, but no immediate threat is present, thus requiring vigilance for threats of low or uncertain probability.
Frustrative non-reward was seen as distinguished from other types of aggression:
Defensive aggression is elicited by a real or perceived threat that leads to a pattern of behaviors directed at terminating the threat. As such, instances of defensive aggression could be considered to belong under the Responses to acute threat Construct.
Offensive (proactive) aggression is elicited by competition over resource acquisition or other positive consequences. This form of aggression often arises from differences in social status and dominance.
Learned helplessness is an important paradigm that has generated much useful data, the majority agreed that it is not clear whether LH can be distinguished from a more general stress response in humans; thus, there is insufficient evidence currently to support LH as an independent Construct.
Summary of Construct Group Deliberations
. . . the participants discussed the Construct of fear from an evolutionary perspective, detailing the critical adaptive value of fear in normal function and survival . . .
The participants discussed the diverse set of elicitors and presentations of fear, ranging from innate to conditioned fear stimuli and phasic or sustained fear. Additional complexity was added by discussing fear within a series of continuums, including imminence, severity, and characteristics of the threat. For instance, threatening stimuli can elicit fear responses; however these responses may be modulated by factors such as cognitive processing and prior experience, thus resulting in alterations that introduce related processes such as inhibition and/or extinction.
Distress Construct Group
The workgroup discussed the many specific types of stress or adversity that could be expected to generate different but also overlapping responses (e.g., anxiety, worry, rumination, anhedonia, frustration, sadness, grief). There was some agreement that it was best to avoid having too high a degree of specificity. . . . Although HPA axis activation (see below) was one of the most frequently nominated elements for the NVS matrix in a pre-workshop survey . . . The HPA axis can therefore be conceptualized as a modulatory system that is invoked by a variety of stimuli and situations and has a variety of effects on cognition and behavior.
Sadness was the most frequently nominated Construct of the pre-workshop survey. . . . The group defined loss as the deprivation of a motivationally significant object or situation. It may be social or nonsocial and may include loss of food, shelter, behavioral control, status rewards, loved ones and relationships. The response to loss may be episodic, in which case it might be called grief, or sustained, in which case it might be called depression. Sadness is evolutionarily conserved and can be studied in non-human primates as a behavior that has the evolutionary purpose of engaging the empathy and support of other members of the same species.
Elements within the Units of Analysis
When identifying behaviors related to Constructs, participants agreed on the importance of considering not only what organisms do when they are stressed/facing adversity, but also what behaviors they do not perform well anymore as a result of being stressed/facing adversity (e.g., disrupted cognition and over-reliance on habits).
For the task of filling in the matrix elements, the group focused on loss, responses to sustained threat, and frustrative non-reward.
(From the mystery expert on Wikipedia. I left the links.)
The hypothalamic–pituitary–adrenal axis (HPA or HTPA axis), also known as the limbic–hypothalamic–pituitary–adrenal axis is a complex set of direct influences and feedback interactions among three endocrine glands: the hypothalamus, the pituitary gland (a pea-shaped structure located below the hypothalamus), and the adrenal (also called "suprarenal") glands (small, conical organs on top of the kidneys).
[It] controls reactions to stress and regulates many body processes, including digestion, the immune system, mood and emotions, sexuality and energy storage and expenditure. It is the common mechanism for interactions among glands, hormones, and parts of the midbrain that mediate the general adaptation syndrome (GAS). While steroids are produced only by vertebrates, the physiological role of the HPA axis and corticosteroids in stress response is so fundamental that analogous systems can be found in invertebrates and monocellular organisms as well.