Friday, 20 November 2015

Negative emotionality, hyper-emotionality and hypo-emotionality as potenital causes of depression



Bruce G Charlton and Joseph Shaw


The broad diagnostic category of DSM Major Depressive Disorder (MDD) was established in 1980 – in practice it seems that MDD can be interpreted as inclusive of patients with a wide range of dysphoric feelings including depression, anxiety, mood swings and emotional blunting/ unemotionality [Watson 1988a, Nutt 2007]. In other words, depressive symptoms may be regarded as a consequence of more than one emotional state; rather as pain may be a consequence of many causes [Charlton 2009].

It has been argued that Major Depressive Disorder is therefore heterogeneous, and can be subdivided into at least three groups, each characterised by a distinctive emotional state.

Negative-emotionality (Negative-E) describes the most obviously depressive group, who mainly experience strong negative emotionality such as misery, anxiety, guilt, fatigue etc.

A second group would be Hyper-emotional (Hyper-E) who experience strong emotions in both negative and positive directions (e.g. they are emotionally unstable, hyper-responsive, subject to mood swings).

A third group would be Hypo-emotional (Hypo-E), with weak or blunted emotions in both negative and positive directions (e.g. they are ‘flat’, demotivated, unresponsive) [REF 1 Charlton].

These states may be characterized by each having a different pattern of
1. emotional strength and 2. Emotional direction (i.e. positive/ negative, both or neither).

As a first test of this hypothesis we conducted an internet survey on 251 subjects recruited through advertisements posted on several depression-related online communities (www.reddit.com/r/depression; www.nomorepanic.co.uk; www.depressionforums.org; http://talk-depression.org). Strength of depressive symptoms was measured using the Beck Depression Inventory [Beck et al 1961], while the strength and directionality of emotions was measured the PANAS (Positive and Negative Affect Scale) [Watson 1988b].


217 subjects were classified into groups of Controls, Negative-, Hyper- and Hypo-Emotionality by using the Positive-Affect (PA) and Negative-Affect NA) sub-divisions of PANAS:

Controls n=27, Lowest 25% NA, Highest 25% PA
Negative-E n=50, Highest 50% NA, Lowest 50% PA
Hyper-E n=76, Highest 50% NA, Highest 50% PA
Hypo-E n=64, Lowest 50%NA, Lowest 50% PA

Severity of depressive symptoms are shown in Table 1:

 
Emotionality
BDI Mean
BDI       SD
p
Positive-E Control
17.3
9.89
Negative-E
43.9
7.21
<0.001
Hyper-E
35.7
9.61
<0.001
Hypo-E
35.8
10.1
<0.001








The results show that despite the ‘control group’ being in the Mild range for depressive symptoms on the BDI; all three of the hypothesized emotionality groups scored were significantly more severe in depressive symptoms than Controls; indeed within the ‘Severe’ depressive symptoms range for BDI scores.

These preliminary results seem clear and consistent with the hypothesis that depressive symptoms may be a consequence of at least three different emotional patterns – Negative-E, Hyper-E and Hypo-E. This conclusion, of course, requires replication in a clinical subject sample evaluated by face-to-face diagnostic interviewing. If correct, one potential implication may be that different emotionality sub-types could benefit from a different therapeutic approach; for example Hyper-E from a trial of serotoninergic agents, and Hypo-E from noradrenaline/ dopaminergic agents [Nutt et al 2007; Charlton 2009]. 


References


Watson, D., Clark, L. A., & Carey, G. (1988a). Positive and negative affectivity and their relation to anxiety and depressive disorders. Journal of Abnormal Psychology97, 346.

Nutt, D., Demyttenaere, K., Janka, Z., Aarre, T., Bourin, M., Canonico, P. L., … & Stahl, S. (2007). The other face of depression, reduced positive affect: the role of catecholamines in causation and cure. Journal of Psychopharmacology, 21, 461-471.

Charlton, B. G. (2009). A model for self-treatment of four sub-types of symptomatic ‘depression’ using non-prescription agents: neuroticism (anxiety and emotional instability); malaise (fatigue and painful symptoms); demotivation (anhedonia) and seasonal affective disorder ‘SAD’. Medical Hypotheses72, 1-7.

Beck, A. T., Ward, C., & Mendelson, M.  (1961). Beck depression inventory (BDI). Archives of General Psychiatry4, 561-571.

Watson, D., Clark, L. A., & Tellegen, A. (1988b). Development and validation of brief measures of positive and negative affect: the PANAS scales. Journal of Personality and Social Psychology54, 1063.

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