Two clinical case studies on bimodal health-related stress assessment

8.1 Introduction

8.1 Introduction

In our modern society, many people experience stress, sometimes for just a brief moment, at other times for prolonged periods of time. Stress can be defined as a feeling of pressure or tension, caused by influences from the outside world [140, Chapter 6]. It can be accompanied by positive and by negative feelings. It affects our physical state, for instance by increasing our heart rate and blood pressure, and freeing stress hormones like (nor)adrenaline and (nor)epinephrine [359], stimulating autonomic nerve action. Stress may become harmful if it occurs for too long or too frequently, or if it occurs during a traumatic experience. It may, for instance, result in depression, insomnia, or PTSD [178, 365, 547, 562]. To make things even worse, such stress related disorders stigmatize the people suffering from them, which in itself is an additional stressor [563, 564].

Depression cannot always be related to a specific cause, though several contributing factors have been identified: for example, genetic vulnerability and unavoidability of stress [232]. More specifically, certain stressful life events (e.g., job loss, widowhood) can lead to a state of depression. Furthermore, chronic role-related stress is significantly associated with chronically depressed mood [333]. Note that the experience of stress is associated with the onset of depression, and not with the symptoms of depression. Insomnia often has a fairly sudden onset caused by psychological, social, or medical stress [267]. Nevertheless, in some cases, it may develop gradually and without a clear stressor. Insomnia is characterized by sleep deprivation, and associated with increased physiological, cognitive, or emotional arousal in combination with negative conditioning for sleep [9]. Traumas can originate from a range of situations, such as warfare, natural disaster, and interpersonal violence such as sexual, physical, and emotional abuse, intimate partner violence, or collective violence (e.g., a bank robbery) [547]. In such cases, a PTSD may arise, which can be characterized by a series of symptoms and causes [178, 365, 547, 562], summarized in Table 8.1.

8.2 Post-Traumatic Stress Disorder (PTSD)

In our study, we studied the emotions in PTSD patients, who suffered from panic attacks, agoraphobia, and panic disorder with agoraphobia [365, 572].

A panic attack is a discrete period in which there is a sudden onset of intense apprehen-

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8 Two clinical case studies on bimodal health-related stress assessment

Table 8.1: Introduction to (the DSM-IV TR [9] criteria for) Post-Traumatic Stress Disorder (PTSD).

Trauma can cause long-term physiological and psychological problems. This has been recognized for centuries. Such suffering (e.g., accompanying a Post-Traumatic Stress Disorder, PTSD), can be characterized in terms of a series of symptoms and causes. Traumas can originate from a range of situations, either short or long lasting; for example, warfare, natural disasters such as earthquakes, interpersonal violence such as sexual, physical, and emotional abuse, intimate partner violence, and collective violence.

Diagnostic criteria as defined by the DSM-IV TR [9] comprise six categories of symptoms, each denoting their various indicators:

1.Exposure of the person to a traumatic event.

2.Persistent reexperience of the traumatic event.

3.Persistent avoidance of stimuli, associated with the trauma, and numbing of general responsiveness (not present before the trauma).

4.Persistent symptoms of increased arousal, not present before the trauma.

5.Duration of the disturbance (symptoms in criteria 2, 3, and 4) is more than one month.

6.The disturbance causes clinically significant distress or impairment in social, occupa-

tional, or other important areas of functioning.

Many other symptoms have also been mentioned; for example, weakness, fatigue, loss of willpower, and psychophysiological reactions such as gastrointestinal disturbances. However, these are not included in the DSM-IV TR diagnostic criteria.

Additional diagnostic categories are also suggested for victims of prolonged interpersonal trauma, particularly early in life. These concern problems are related to: 1) regulation of affect and impulses, 2) memory and attention, 3) self-perception, 4) interpersonal relations, 5) somatization, and 6) systems of meaning. Taken together, PTSD includes a broad variety of symptoms and diagnostic criteria. Consequently, the diagnosis is hard to make, as is also the case for various other mental disorders.

sion, fearfulness or terror, often associated with feelings of impending doom. During these Panic Attacks, symptoms such as shortness of breath, palpitations, chest pain or discomfort, choking or smothering sensations, and fear of ‘going crazy’ or losing control are present. The panic attack has a sudden onset and builds rapidly to a peak (usually in 10 minutes or less). Panic attacks can be unexpected (uncued), situationally bound (cued), or situationally predisposed [572]. Agoraphobia is anxiety about, or avoidance of, places or situations from which escape might be difficult (or embarrassing), or in which help may not be available in the event of having a panic attack or panic-like symptoms [572]. Panic disorder with agoraphobia is characterized by both recurrent and unexpected panic attacks, followed by at least one month of persistent concern about having another panic attack, worries about the possible implications or consequences of such attacks, or a significant behavioral change related to these attacks. The frequency and severity of Panic attacks vary widely, but panic

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8.2 Post-Traumatic Stress Disorder (PTSD)

disorder as described here has been found in epidemiological studies throughout the world. Panic disorders without and with agoraphobia are diagnosed two to three times as often in women as in men. The age of onset of panic disorders varies considerably, but most typically lies between late adolescence and the mid-thirties. Some individuals may have episodic outbreaks with years of remission in between, and others may have continuous severe symptomatology [572].

Due to its large inter-individual variability and its broad variety of symptoms, the diagnosis of PTSD is hard to make [178, 365, 547, 562]. At the same time, it is clear that an efficient treatment of PTSD requires an objective and early diagnosis of the patients’ problems and their therapeutic progress. Assessing the emotional distress of a patient is therefore of the utmost importance. Therapists have developed a range of questionnaires and diagnostic measurement tools for this purpose [353, 572]. Regrettably, these may be experienced as a burden by clients, because it takes the time and willingness of the clients to complete them.

In addition, several other problems arise when a clinician tries to assess the degree of stress in the patient. First, during the appraisal of a stress response, a stressor may not always be seen as stressful enough to be a cause for the mental illness. In other words, although the client may experience it as hugely stressful, the clinician might not always acknowledge it as such. Second, when measuring the response to a stressor, the clinician may rely on introspection and expertise, but these are always to some extent subjective and they also rely on the communicative abilities, truthfulness, and compliance of the client in question. Third, at times it may not be completely clear which (aspect of) the experienced stressor led to the excessive stress response. Finally, the evaluation of the progress in treatment is complicated by its gradualness and relativity.

Given these considerations, it is abundantly clear why researchers have searched for more objective, unobtrusive ways to measure emotions in patient populations. In other words, in addition to standardizing their professional approaches, therapists have sought for new sorts of Computer-Aided Diagnosis (CAD) that are applicable to real-life situations and measure real emotions.

In the following sections, we will first describe both the storytelling and trauma reliving techniques themselves. They provided us with stretches of speech, which we analyzed with respect to a series of signal characteristics to detect emotions. After discussing our speech analysis technique, we will explain how the Subjective Unit of Distress is standardly measured. This will then be followed by a more detailed report of our experimental study. We will end the chapter with an evaluation of our novel approach to stress and emotion measurement.

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