Building a Definition of Irritability From Academic Definitions and Lay Descriptions

Study 1: Method

Study 1: Findings

Study 2: Method

Sampling, recruitment, and data collection

A community sample was recruited from Guelph, Ontario, and Kelowna, British Columbia. Participants were informed of the study via poster advertisements placed in a variety of public spaces. Participants were eligible if they were over the age of 18, were fluent in English, and had experienced irritability in the past 2 weeks. We adopted a purposive sampling strategy by first screening potential participants by telephone to achieve maximum variation with respect to age, sex, ethnicity, physical health, and mental health. A total of 39 (23 women) interviews were conducted in 2010. Table 1 provides a detailed description of the demographics. Sixteen participants reported at least one mental illness, including depression (n = 10), bipolar disorder (n = 4), schizophrenia (n = 2), social anxiety (n = 2), ADHD (n = 2), and PTSD (n = 1). Fifteen participants reported at least one physical condition, with the most common being chronic pain (n = 9), diabetes (n = 3), and arthritis (n = 2). Hepatitis C, chronic fatigue syndrome, endometriosis, thyroid problem, heart condition, hypertension, sleep apnea, and permanent disability (cause unspecified) were reported by one participant, respectively.

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Table 1.

Participant demographics (N = 39).

Variable	N	% of total N
Age
19–29	14	35.8
30s	8	20.5
40s	6	15.4
50s	7	17.9
60s	4	10.3
Relationship status
Single	17	43.6
Married/common law	13	33.3
Separate/divorced	5	12.8
Widowed	2	5.1
Other	2	5.1
Number of children a
0	25	64.1
1–2	9	23.1
3–4	4	10.3
Employment a
Part-time employment	14	35.8
Full-time employment	8	20.5
On medical leave/disability	6	15.4
Student	6	15.4
Retired	4	10.3
Ethnicity a
European (White)	29	74.4
First Nations	2	5.1
South Asian	1	2.6
Other	6	15.4
Sexual orientation
Heterosexual	38	97.4
Gay/lesbian	1	2.6
Education
Some high school	5	12.8
Graduated from high school (12/13)	4	10.3
Some college/university	15	38.5
College/university degree	12	30.8
Graduate degree	3	7.7
Income a
0–19,999	20	51.3
20,000–39,999	7	17.9
40,000–59,999	10	25.6
60,000–79,999	1	2.6

Note. ^aOne participant did not respond.

The interviews were conducted by one of two trained undergraduate research assistants (one male and one female), and were audio-recorded for later transcription. Interviews lasted between 35 minutes and 2 hours. Participants were asked to describe what irritability means to them and to describe two or more recent personal experiences of perceived irritability. This study had ethical clearance from the University of Guelph and the University of British Columbia – Okanagan.

Study 2: Findings

All participants made some attempt to provide an explicit definition; however, many found this difficult. Some stated their difficulty. “It’s hard to put in words” (P9). A few participants discursively displayed their difficulty by using a variation of the term irritability as the definition (e.g., “When I’m irritable, I’m easily irritated,” P13). Others displayed their discursive difficulty by altering their definition over the course of the interview.

Contrary to the difficulty participants had in articulating an explicit definition of irritability, they displayed relative discursive ease describing instances of irritability. Analysis of the participants’ explicit definitions and experiential descriptions of irritability resulted in the identification of two main themes: (a) irritability and various negative affective states and (b) control, as well as a number of subthemes.

Main theme 1: Irritability and various negative affective states

This main theme captures the ways in which the participants discursively constructed relationships between irritability and various negative affective states (see Figure 1).

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Figure 1.

Relationship between irritability and various negative affective states.

Subtheme 1: Synonyms for irritability

All of the participants equated the concept of irritability with at least one negative affective state. The most common synonyms were “anger,” “frustration,” and “annoyance.” Many participants initially likened irritability to anger, but as the interview progressed they clarified what they meant by using adverbs (e.g., “mild” [anger]) and adverb phrases (e.g., “less than violent” [anger]) to downplay the volatile connotations. Adverbs were also used (to a lesser degree) with other synonyms (e.g., “slightly” [agitated]). In contrast to talk that downplayed synonyms for irritability, some of the negative affective states were inflated with adverbs to intensify their meaning (e.g., “really” [upset], “intensely” [agitated]).

Subtheme 2: Placement of irritability on a continuum

Many participants placed irritability on a continuum implicitly, “irritability is a preparation to anger” (P23). However, several participants made more explicit references to a continuum. “The irritability is gone to frustration, the frustration is gone to anger” (P31).

In doing so, the participants presented irritability as having a specific place in a range of negative emotions. That is, there was an emotional process that took place in which these participants “worked up to” an experience of irritability and, in some cases, moved past it.

Subtheme 3: Cumulative emotional process

The idea that irritability was a process was also apparent in participants’ descriptions of a cumulative effect. That is, small sources of irritation could build up to a more intense feeling. This process of building up to a higher level of intensity was sometimes described as the irritability and sometimes it was described as leading to the irritability.

I guess I found that when I’m irritable, for me, that means I mean I’m likely to like go off eventually … kind of like a little thing bugging you continuously until you finally blow up. (P6)

Affect

Both the academic definitions and the lay descriptions juxtapose irritability with a number of emotions/affect, but there is particular attention to anger. Anger was a component of most academic definitions, but the word “anger” was typically qualified in some way. Similarly, the community participants sometimes described irritability as anger but typically downplayed the experience as something less than anger. Anger is thus clearly important for an understanding of the construct of irritability, but anger is neither sufficient in describing it nor is it accurate in all cases. Sometimes irritability was experienced or defined in relation to something other than anger; most notably to similar constructs such as annoyance and frustration, but occasionally to emotions that are very different (e.g., sadness and anxiety). A definition of irritability thus seems incomplete without acknowledging the relationship to anger, but it must be flexible enough to allow for varied experiences. In our definition we have followed the example of authors who have used general phrases such as “negative affect” (Smith, Houston, & Stucky, 1984), but we have also provided specific examples to help orient the reader.

Outward Expression

In the academic definitions, the behavioural expression of irritability was most often described as a form of aggression. Many described explosive outbursts, quick temper, or expressed anger, but none described violent aggression. Therefore, although the behaviour may be “explosive” it is implicitly constrained to some degree. This constraining was even more apparent in the lay descriptions, which makes clear that the outward expression may not always occur, and when it does, its manifestation is extremely varied. As such our definition notes that the outward expression of irritability may occur, but does not make the behavioural component a dominant element.

Process

The lay participants’ talk made clear that irritability was experienced as a process. They often placed it on a continuum of affect, and talked about a cumulative emotional process in which a number of things could build up to the experience of irritability. In other words, the source of the irritability could be multiple factors and the proverbial “straw that breaks the camel’s back” could be rather small. This is key and helps explain why irritability can feel unjustified or disproportionate to the source. This is also somewhat at odds with academic definitions that used phrases such as “quick temper” (Caprara et al., 1985; Smith et al., 1984) and described behavioural “outbursts” (Snaith & Taylor, 1985; Stringaris, 2011). Our definition attempts to reconcile this by describing irritability as an emotional process.

Control

The experience of control was a dominant theme in the interviews. Participants explicitly described feeling a loss of control over their emotions, their physiological reactions, and over the situation, but often a very deliberate control of their behaviours. By contrast, the word control is used in only four academic definitions to describe a loss of control over temper (Born & Steiner, 1999; Snaith & Taylor, 1985), anger (Elbe & Lalani, 2012; Snaith et al., 1978), and aggression (Elbe & Lalani, 2012). However, when one looks closely at how participants described their lack of control over their irritability, there are some similarities between the two studies. For example, participants often described a proneness to feeling irritable, which was similar to how some academic definitions qualified the experience of irritability as a predisposition, proneness, readiness, or propensity toward a particular emotion, behaviour, or cognition.

The main differences here are largely because the academic definitions take the perspective of a person observing someone else’s irritability (i.e., there was no just cause for the outward expression) and the participants’ descriptions take the perspective of someone experiencing irritability (i.e., who experiences difficulty controlling an emotional reaction that feels disproportionate to the immediate source). In hindsight, this is an obvious difference; however, it is not inconsequential. We believe that because previous academic definitions considered the experience from the observer’s perspective they have largely missed describing how control is a key element of the experience of irritability and have perhaps overestimated the importance of explosive outbursts and other overt behavioural manifestations while underestimating the extent to which behaviours are actually controlled. Our definition makes control explicit and we later discuss why this is important in the measurement and treatment of irritability.

Source of Irritability

Some of the academic definitions and many of the lay descriptions mention the source of the irritability, often pointing out that the source does not seem to justify the emotional reaction. When considering how to include the source of the irritability into a definition, we were very cognizant of the fact that simply including potential sources would be extremely judgemental. In addition, this would be inaccurate because as discussed before, the experience of irritability can be a cumulative process and the immediate source may only be one of many causing the experience of irritability. However, we wanted the definition to acknowledge that the immediate source often feels disproportionate to the individual’s experience of irritability.

The Definition

In building this definition, we have paid special attention to the dominant results of both studies and have incorporated affect, outward expression, process, control, and source:

Irritability is an emotional process that is characterized by a proneness to experience negative affective states, such as anger, annoyance, and frustration, which may or may not be outwardly expressed. Irritability often includes a feeling that one’s emotional responses are unjustified or disproportionate to the immediate source, but difficult to control.

Relationship of Our Definition to Previous Definitions of Irritability

The content analysis of published definitions of irritability informed the development of our definition. This strengthens our definition because it builds on a current academic understanding of the concept. As such, there are similarities in our definition compared to others, but there are also important points of departure. For example, the most common qualifier used in the academic definitions was that irritability occurs with minimum provocation. This is similar to the participants’ descriptions of feeling unjustified for their irritability and feeling a lack of control. We opted to use the language of feeling unjustified because this takes the perspective of the person experiencing the irritability. This also helps to distinguish irritability from anger, which is typically accompanied by the belief that one’s anger is justified and that some wrongdoing has occurred. Most academic definitions make reference to an aggressive behavioural expression of irritability. We opted to minimize the outward expression of irritability because our interview data suggested that behavioural outcomes were often constrained. This also helps avoid confusion with related constructs such as aggression.

The two most significant differences in our definition, compared to previous academic definitions, are that we have described irritability as a process and that it is perceived as difficult to control. None of the definitions we reviewed use the word “process.” Yet, the participants we interviewed often spoke about irritability as a cumulative process that unfolds over time. The lack of the word “process” in previous definitions is telling, and we believe this may be related to a focus on the behavioural manifestation of irritability (which to the observer would seem to appear suddenly).

The idea that the affective experience of irritability is difficult to control is also a departure from previous definitions. One might argue that difficulty controlling one’s emotional experience is not unique to irritability, and that feeling a loss of control over one’s emotions may be more important in discriminating between clinical and nonclinical populations. However, our community sample was comprised of men and women with and without medical or psychiatric diagnoses. Across our entire sample, the notion that one should be able to control one’s feelings of irritability (i.e., because the experience itself is not warranted or justified), and that it is difficult to exert this control, was extremely common.

Related Constructs

Participants commonly used the word anger, but as we have argued, irritability was always downplayed as something less than anger. Our definition makes clear that anger might be an outcome of irritability, but that it is distinct from it. There are also a number of academic terms that are related to irritability, but that we believe are distinct from our proposed definition. For example, trait anger has been defined as, “a stable personality dimension of anger proneness or tendency to experience state anger” (Deffenbacher et al., 1996, p. 131). Similar to our definition, there is a proneness to anger, but we have not defined irritability as a trait and we have left open the possibility that irritability might make one prone to negative emotional experiences other than anger. Hostility is similarly described as a trait, and thus argued to be different from irritability (Born & Steiner, 1999). Anger attack is also related and defined as, “a rapid onset of intense anger and a crescendo of autonomic arousal that occur upon provocation described as trivial by the individual” (Mammen et al., 1999, p. 633). A key difference between anger attack and our definition of irritability is that the experience of irritability is not necessarily rapid. In fact, we have emphasized how the experience can build quite slowly. We also opted not to include physiological experiences in our definition. These were rarely included in the academic definitions, and although study participants gave accounts of their physiological responses, these were almost always in response to direct questioning and not spontaneous descriptions.

Application and Future Research

By integrating both academic and lay perspectives, we believe that our definition will facilitate further research and provide a better understanding of irritability for health practitioners. In particular, our inclusion of control is novel, opens up new questions for research, and points to a potential clinical focus. For example, studies could explore whether people who have a high need for control experience more irritability, and examine factors that help some people control their irritability better than others. Clinically speaking, therapists could address the extent to which clients’ perceive their irritability to be beyond their control. Mindfulness- and acceptance-based approaches, which cultivate feelings of awareness, acceptance, and nonjudgement, may be particularly beneficial in this regard (Baer, 2003; Hayes, Levin, Plumb-Vilardaga, Villatte, & Pistorello, 2013).

Although a lack of control was commonly reported as a cause of irritability in our community sample, our initial microcoding resulted in over 200 different sources for irritability. With so many different sources, it is possible that people are either not very good at identifying the “real” cause of their irritability or almost anything can be a source of irritability. Interestingly, this parallels the lack of clarity in the scientific literature regarding what causes irritability. In a clinical context, it may be helpful for clients to identify patterns in the sources of their irritability. Emerging research does support participants’ reports that irritability is sometimes caused by an underlying medical or psychiatric condition, and there is a pressing need to better understand the biological underpinnings of this process and how social experiences interact with the biological.

Differences between academic and lay descriptions of irritability emphasize that irritability can appear different from a self or other perspective. This is consistent with studies suggesting a lack of congruence between self-reported irritability and “other-rater” reports (Yang et al., 2012) and indicates the importance of obtaining self-report and observer reports in clinical practice. Our findings also suggest the need for qualitative studies that ask participants to describe and compare different affective experiences, such as irritability and anger.

Lastly, future research might also explore how gender roles predict feelings of irritability and whether irritability is perceived differently when it is expressed by a man versus a woman. Our definition applies equally to men and women, which is important because recent work on the development of a scale for irritability suggests that irritability is experienced similarly by men and women (Holtzman, O’Connor, Barata, & Stewart, 2014). However, although the experience may be similar, it is possible that men and women may attribute their irritability to different sources or express irritability differently because of their gender roles.

Limitations

Our definition has downplayed the importance of the behavioural expression of irritability largely because the lay participants made clear that they often constrained their behaviour when experiencing irritability. However, it is possible that people underestimate how well they actually constrained their behaviour and/or deliberately left out behaviour that may be unflattering. Nevertheless, our definition leaves open the possibility that observable behaviour is displayed during the experience of irritability. Our analysis of control within the experience of irritability developed slowly and it was not until the interviews and analyses were complete that the authors fully appreciated the importance of control. As such we did not ask the participants specific questions about control and this will need to be more fully explored in future work.

We also point out that our qualitative interviews were conducted with predominantly Caucasian participants and that the academic definitions of irritability have, almost exclusively, been proposed by researchers at North American and Western European institutions. The role of social and cultural factors in the experience and expression of irritability needs further exploration. Our community sample of adults also limits our definition. Levels of irritability have been documented among infants, children, and adolescents and a lifespan approach to studying irritability would be most appropriate as the field moves forward.