The determinants and treatment of simple phobias

Genetic contributions to anxiety disorders: where we are and where we are heading

Anxiety disorders are among the most common psychiatric disorders worldwide. They often onset early in life, with symptoms and consequences that can persist for decades. This makes anxiety disorders some of the most debilitating and costly disorders of our time. Although much is known about the synaptic and circuit mechanisms of fear and anxiety, research on the underlying genetics has lagged behind that of other psychiatric disorders. However, alongside the formation of the Psychiatric Genomic Consortium Anxiety workgroup, progress is rapidly advancing, offering opportunities for future research.Here we review current knowledge about the genetics of anxiety across the lifespan from genetically informative designs (i.e. twin studies and molecular genetics). We include studies of specific anxiety disorders (e.g. panic disorder, generalised anxiety disorder) as well as those using dimensional measures of trait anxiety. We particularly address findings from large-scale genome-wide association studies and show how such discoveries may provide opportunities for translation into improved or new therapeutics for affected individuals. Finally, we describe how discoveries in anxiety genetics open the door to numerous new research possibilities, such as the investigation of specific gene-environment interactions and the disentangling of causal associations with related traits and disorders.We discuss how the field of anxiety genetics is expected to move forward. In addition to the obvious need for larger sample sizes in genome-wide studies, we highlight the need for studies among young people, focusing on specific underlying dimensional traits or components of anxiety.

Pharmacological treatment of anxiety disorders: current treatments and future directions

Modern pharmacological treatments for anxiety disorders are safer and more tolerable than they were 30 years ago. Unfortunately, treatment efficacy and duration have not improved in most cases despite a greater understanding of the pathophysiology of anxiety. Moreover, innovative treatments have not reached the market despite billions of research dollars invested in drug development. In reviewing the literature on current treatments, we argue that evidence-based practice would benefit from better research on the causes of incomplete treatment response as well as the comparative efficacy of drug combinations and sequencing. We also survey two broad approaches to the development of innovative anxiety treatments:the continued development of drugs based on specific neuroreceptors and the pharmacological manipulation of fear-related memory. We highlight directions for future research, as neither of these approaches is ready for routine clinical use.

The development of anxiety disorders in childhood: an integrative review

We present an integrative review of the development of child anxiety, drawing on a number of strands of research. Family aggregation and genetic studies indicate raised vulnerability to anxiety in offspring of adults with the disorder (e.g. the temperamental style of behavioural inhibition, or information processing biases). Environmental factors are also important; these include adverse life events and exposure to negative information or modelling. Parents are likely to be key, although not unique, sources of such influences, particularly if they are anxious themselves. Some parenting behaviours associated with child anxiety, such as overprotection, may be elicited by child characteristics, especially in the context of parental anxiety, and these may serve to maintain child disorder. Emerging evidence emphasizes the importance of taking the nature of child and parental anxiety into account, of constructing assessments and interventions that are both disorder specific, and of considering bidirectional influences.

Context and renewal of conditioned fear: an experimental evaluation using 20% carbon dioxide-enriched air as an unconditioned stimulus

This analogue experiment used fear conditioning and extinction procedures to establish and reduce fearful responding and then test for fear renewal following a context change. Healthy undergraduates (N=61) underwent a differential fear conditioning procedure using geometric shapes as conditioned stimuli (CS) and inhalations of 20% CO(2)-enriched air as an aversive unconditioned stimulus (US). Across phases (i.e., habituation, acquisition, extinction, and test), red and green ambient lighting served as contextual stimuli, and electrodermal and evaluative ratings were assessed as indices of conditioned fear. The control group underwent extinction and test phases under identical conditions (i.e., no context changes). The experimental groups either underwent acquisition and test phases in one context and the intervening extinction phase in a different context (A-B-A), or underwent acquisition and extinction phases in one context and the test phase in a novel context (A-A-B). Consistent with expectation, fear renewal was observed when the test context matched the acquisition context. This effect was modest for electrodermal responses, but reasonably robust for evaluative responses. The role of context in the subsequent renewal of fear following exposure-based treatment is discussed.

The Importance of Behaviour in the Maintenance of Anxiety and Panic: A Cognitive Account

The theoretical and empirical basis of commonly accepted propositions concerning the role of behaviour in the practice of behavioural psychotherapy for anxiety problems is considered. A number of problems are identified, and an alternative, more explicitly cognitive hypothesis is described. According to this cognitive account, there is both a close relationship and specific interactions between “threat cognitions” and “safety seeking behaviour”. For any individual, safety seeking behaviour arises out of, and is logically linked to, the perception of serious threat. Such behaviour may be anticipatory (avoidant) or consequent (escape). Because safety seeking behaviour is perceived to be preventative, and focused on especially negative consequences (e.g. death, illness, humiliation), spontaneous disconfirmation of threat is made particularly unlikely by such safety seeking behaviours. By preventing disconfirmation of threat-related cognitions, safety seeking behaviour may be a crucial factor in the maintenance of anxiety disorders. The implications of this view for the understanding and treatment of anxiety disorders are discussed.

Reinstatement of conditioned responses in human differential fear conditioning

The present study aimed at investigating reinstatement of conditioned responding in human classical conditioning using a differential fear conditioning paradigm. Reinstatement is defined as the return of extinguished conditioned responses due to the experience of one or more unexpected USs. As expected the reinstatement group showed reinstatement of US-expectancy while a similar return of conditioned responses was not present in the control group. In the fear ratings a similar pattern was observed. In addition, and in line with previous findings, we found that the more negative the CS+ remained after extinction, the more return of conditioned responding was observed. Clinical implications and suggestions for further research are discussed.

Cognitive vulnerability: a model of the etiology of fear

This paper attempts to fill the partial theoretical vacuum surrounding the understanding of fear acquisition. A review of recent and contemporary theories of the etiology of fear is presented, serving as a justification for further theorizing and allowing for greater understanding of those aspects of fear that remain to be adequately explained. A new model of the etiology of specific fears is subsequently put forward and the various aspects and implications of this model are discussed. How an individual perceives a stimulus is proposed as being critical in determining fear in relation to the stimulus. In particular, perceptions of the stimulus as uncontrollable, unpredictable, dangerous and disgusting create a schema of vulnerability. The Cognitive Vulnerability Model integrates much of the extensive body of research on fears and specific phobias into a unifying theory of the etiology of fear. The model offers parsimonious explanations for the various characteristics of specific fears and phobias.

Multimodal classical conditioning of fear: contributions of direct, observational, and verbal experiences to current fears

The authors propose that a multimodal classical conditioning model be considered when clinicians or clinical researchers study the etiology of fears and anxieties learned by human beings. They argue that fears can be built through the combined effects of direct, observed, and verbally presented classical conditioning trials. Multimodal classical conditioning is offered as an alternative to the three pathways to fear argument prominent in the human fear literature. In contrast to the three pathways position, the authors present theoretical arguments for why "learning by observation" and "learning through the receipt of verbal information" should be considered classical conditioning through observational and verbal modes. The paper includes a demonstration of how data, commonly collected in research on the three pathways to fear, would be studied differently using a multimodal classical conditioning perspective. Finally, the authors discuss implications for assessment, treatment, and prevention of learned fears in humans.

Differential aversive outcome expectancies for high- and low-predation fear-relevant animals

There is now considerable evidence that phobic responding is associated with a bias towards expecting aversive or traumatic outcomes following encounters with the phobic stimulus (e.g. Behavioural Brain Sci. 18 (1995) 289-325; Phobias: A Handbook of Theory, Research and Treatment. Wiley, Chichester, 1997). In terms of conditioning contingencies, this can be described as a bias towards expecting an aversive unconditioned stimulus (UCS) following a phobic conditioned stimulus (CS). The disease-avoidance model of animal fears (Anxiety Res. 4 (1992a) 314; Matchett and Davey, 1991) suggests that common animal fears may be mediated by at least two kinds of selective associations: (1) a bias towards expecting physically harmful consequences associated with predatory animals, and (2) a bias towards expecting disgust or disease-relevant consequences associated with animals that are fear-relevant (FR) but normally physically harmless. The present study investigated this model of selective associations by comparing the UCS expectations elicited by high-predation FR, low-predation FR and safe (fear-irrelevant) animals. The results indicate that high-predation animals are selectively associated with a pain relevant UCS, whilst low-predation animals are selectively associated with a disgust-relevant UCS. Safe animals were not strongly associated with either class of UCS. These findings provide evidence for a possible associative mechanism by which changes in nonspecific levels of disgust sensitivity may directly affect levels of fear to low-predation FR animals.

Non-associative fear acquisition: a review of the evidence from retrospective and longitudinal research

It is axiomatic that the capacity to experience fear is adaptive, enabling rapid and energetic response to imminent threat or danger. Despite the generally accepted utility of functional fear, the nature of maladaptive fear remains controversial. There is still no consensus about how specific fears and phobias are acquired and modulated. Two major schools of thought are apparent: those suggesting dysfunctional fear arises largely as the result of associative-conditioning processes versus those who favour more biologically based etiological explanations. In this regard, the non-associative model of fear acquisition postulates the existence of a limited number of innate, evolutionary-relevant fears, while emphasising conditioning modes of onset for evolutionary-neutral fears. Recent retrospective and longitudinal studies have tested predictions from the non-associative model. In general, findings support non-associative hypotheses and are difficult to reconcile with neo-conditioning explanations of fear acquisition. These data suggest that four pathways to fear may provide the most parsimonious theory of fear etiology. The theoretical and practical implications of adding a fourth, non-associative path to Rachman's (Behav. Res. Ther. (1977) 15, 375-387) three 'associative' pathways are discussed. Unresolved issues requiring further investigation are considered.

The effect of UCS inflation and deflation procedures on 'fear' conditioning

Davey (1992: Classical conditioning and the acquisition of human fears and phobias: a review and synthesis of the literature. Advances in Behaviour Research and Therapy, 14, 29-66) hypothesized that subjective revaluation of an unconditioned stimulus (UCS) would determine the strength of the autonomic conditioned response (CR) in the fear conditioning paradigm. The purpose of the present study was to examine the effect of UCS aversiveness on the CR strength in the fear conditioning paradigm. The UCS aversiveness was controlled by the UCS intensity; that is, the UCS intensity was increased for the inflation group or decreased for the deflation group. Thirty subjects were randomly assigned to the inflation or the deflation group, and they participated under both experimental and control conditions. All subjects went through the pretest, the acquisition of classical conditioning, the UCS intensity operation, and the test sessions. The indices of the CR were skin conductance responses (SCRs) and a subjective aversion to the conditioned stimulus (CS). The main results were as follows. (1) The CR strength measured by SCR was increased by the UCS inflation and decreased by the UCS deflation. (2) The subjective aversiveness of the CS was not sensitive to both manipulations of UCS intensity. These results suggested that the autonomic CR strength might be influenced by the subjective revaluation of UCS, as Davey (1992) described. The result from the test of the subjective aversiveness of the CS, however, could not support Davey's model. The difference between expressions of the SCR and the subjective aversiveness of the CS might be caused by different learning systems.

Assessing the perceived predictability of anxiety-related events: a report on the perceived predictability index

Predictability, or lack thereof, is believed to play a critical role in the development and maintenance of anxiety, with unpredictability being associated with heightened levels of anxious and fearful responding. Despite the potential importance of predictability in theoretical accounts of emotional dysregulation, currently no standardized assessment instrument exists to assess predictability perceptions for anxiety-related events. The present series of four investigations report on an initial attempt to develop a self-report instrument (i.e., Perceived Predictability Index, PPI) that can measure predictability perceptions for the occurrence, duration, and termination of anxiety-related events. Initial item selection and factor structure of the instrument was based on a large sample of participants and yielded a two-factor solution: (1) prediction of anxiety-related environmental events and (2) prediction of internal events. Our subsequent studies show that the PPI possesses adequate levels of internal consistency and temporal stability over time. Additionally, the PPI demonstrated adequate divergent and convergent validity relative to other standard anxiety and fear measures. The internal dimension of the scale also demonstrated predictive validity for emotional responding during a biological challenge test. We discuss these findings in relation to the role of perceived predictability in the study of anxious and fearful responding, and offer directions for future research.

Etiology of childhood phobias: current status of Rachman's three pathways theory

Despite advances in the assessment and treatment of childhood phobias, little is known about their etiology. Rachman has proposed that phobias are acquired through three different pathways: direct conditioning, modeling or instructions/information. We evaluate the empirical support for Rachman's theory in relation to the origins of childhood phobias. Although we find support for Rachman's theory, a number of methodological and theoretical issues are emphasized. For example, insufficient attention has been given to the reliability and validity of retrospective subject reports on the acquisition of childhood phobias. Also some findings on the origins of childhood fears and phobias are more consistent with a nonassociative account of phobia onset, thus providing an interesting challenge to Rachman's theory.

The etiology of childhood spider phobia

Twenty-six girls with a clinical spider phobia and 26 matched control girls were interviewed about conditioning, modeling, and negative information experiences in connection with spiders. In addition, parents of the phobic girls were independently interviewed about the origins of their child's phobia. Phobic children more often reported aversive conditioning experiences with spiders than did control children. Also, in a number of cases, conditioning events described by the phobic children were confirmed by their parents, a result that replicates the findings of Merckelbach, Muris and Schouten (1996; Behaviour Research and Therapy, 34, 935-938). Taken together, the results contradict a strong version of the non-associative account of phobias and suggest that in at least some cases, conditioning events may contribute to the development of (childhood) spider phobia.

Pathways to fear in spider phobic children

Twenty-two children with spider phobia were interviewed about the origins of their fear. More specifically, children were asked about conditioning events, modeling experiences, and negative information transmission. To evaluate the reliability of the information provided by the children, parents were independently interviewed about the origins of their children's phobias. While 46% of the children claimed to have always been afraid, 41% ascribed the onset of their fear to aversive conditioning events. The large majority of these events were confirmed by parents. These findings cast doubts on a strong version of the non-associative account of spider phobia, i.e. the idea that spider phobia is acquired in the complete absence of learning experiences.

Vulnerability representation: the role of perceived dangerousness, uncontrollability, unpredictability and disgustingness in spider fear

It was proposed that cognitive vulnerability representations relating to the perceived uncontrollability, unpredictability, dangerousness and disgustingness of spiders are important factors in the fear of spiders. One-hundred and ninety-two first-year psychology students completed a questionnaire measuring the four vulnerability variables, spider fear and learning history. It was found that fear of spiders was highly correlated with each of the four vulnerability variables. In addition, greater fear of spiders was found for females in comparison with males and this was associated with differential perceptions of spiders as uncontrollable, unpredictable, dangerous and disgusting. Finally, the vulnerability variables accounted for significantly more variance in fear scores than the experience of a number of classical conditioning, vicarious and informational learning events. It is argued that there is value in considering a person's perception of the uncontrollability, unpredictability, dangerousness and disgustingness of spiders in order to better understand individual differences in spider fear.

The role of parental fearfulness and modeling in children's fear

The present study investigated the contribution of parental modeling to the fearfulness of children. Forty children (aged 9-12) who were referred to an outpatient treatment centre filled out the trait version of the Spielberger State-Trait Anxiety Inventory for Children (STAIC) and the revised version of the Fear Survey Schedule for Children (FSSC). The parents of the children completed adult versions of the STAI-trait and the FSS. In addition, parents rated to what extent they generally expressed fears to their children. Results showed that trait anxiety in children was positively associated with trait anxiety of both the mother (r = 0.34, P < 0.05) and the father (r = 0.31, P < 0.05). Fearfulness of the children was only related to fearfulness of the mother (r = 0.56, P < 0.001). Most importantly, the data showed that modeling played a role in this relationship. A linear association between FSSC scores and mothers' rating of expressing fears to their children was found. That is to say, children of mothers who never expressed their fears had the lowest FSSC scores, children of mothers who often expressed their fears had the highest FSSC scores, whereas children of mothers who sometimes expressed their fears scored in between.

Theoretical foundations of cognitive-behavior therapy for anxiety and depression

Cognitive-behavior therapy (CBT) involves a highly diverse set of terms and procedures. In this review, the origins of CBT are briefly considered, and an integrative theoretical framework is proposed that (a) distinguishes therapy interventions targeted at circumscribed disorders from those targeted at generalized disorders and (b) distinguishes interventions aimed at modifying conscious beliefs and representations from those aimed at modifying unconscious representations in memory. Interventions aimed at altering consciously accessible beliefs are related to their theoretical bases in appraisal theories of emotion and cognitive theories of emotion and motivation. Interventions aimed at modifying unconscious representations are related to their theoretical bases in learning theory and findings from experimental cognitive psychology. In the review, different formulations of CBT for anxiety disorders and depression are analyzed in terms of this framework, and theoretical issues relating to self-representations in memory and to emotional processing are considered.

One-session cognitive treatment of dental phobia: preparing dental phobics for treatment by restructuring negative cognitions

The purpose of this study was to investigate the effectiveness of a single session of cognitive restructuring in a sample of phobic dental patients. Fifty-two patients were randomly assigned to one of three conditions: cognitive restructuring (modification of negative cognitions), provision of information (about oral health and dental treatment), and a waiting list control condition. Both interventions maximally lasted one hour. In comparison with the waiting list control condition and the information intervention condition, the cognitive intervention condition not only showed a large decrease in frequency and believability of negative cognitions, but also exhibited a clear decline in dental trait anxiety. Analysis at a follow-up of one year demonstrated a further, drastic reduction in dental anxiety in both intervention conditions, wherein the difference among these conditions was not maintained. It is concluded that it is possible to obtain substantial reductions of dental trait anxiety through a single session of cognitive restructuring. Nevertheless, repeated exposure to the dental situation seems necessary for a further reduction of anxiety.

Effects of endorphin blocking on conditioned SCR in humans

In order to test the hypothesis that low levels of endogenous opioids (endorphins) predispose to strong conditioning effects, female Ss (N = 36) were assigned to a placebo group, a low-dose naltrexone group, or a high-dose naltrexone group and then underwent a classical conditioning procedure. This procedure consisted of an acquisition phase in which all Ss received 5 pairings of a CS+ (neutral picture) and a UCS (100 dB white noise). The CS- (neutral picture) was never followed by a UCS. During extinction, Ss received 4 unreinforced presentations of CS+ and CS-. Throughout the experiment, skin conductance responses (SCRs) to the CSs and UCSs were recorded. Acquisition was successful in that CS+ slides elicited stronger SCRs than CS- slides. However, during acquisition, there was no interaction between drug and differential response (CS+ vs CS-). During extinction, there was no overall remaining effect of conditioning. Again, no evidence was found to suggest that (remaining) effects of conditioning were stronger in the naltrexone treated Ss than in the placebo Ss. If anything, the opposite seemed to be true with especially high-dose naltrexone Ss showing relatively weak conditioning effects.

Pathways to spider phobia

Using a revised version of the Phobic Origin Questionnaire (POQ; Ost, L. G. & Hugdahl, K. Behaviour Research and Therapy, 19, 439-477; 1981), the present study examined whether conditioning experiences, modeling experiences, and/or informational learning experiences were more often reported by spider phobics (n = 41) than by non-fearful controls (n = 30). The two groups did not differ with regard to the overall frequency of conditioning or modeling events. Remarkably, the frequency of informational learning was higher among non-fearful Ss than among phobics. Although the limitations inherent to the retrospective nature of the present study should be borne in mind, the data suggest that, at least in spider phobics, conditioning events, modeling experiences, and/or informational learning do not necessarily give rise to phobic fears.

Origins of fear of dogs in adults and children: the role of conditioning processes and prior familiarity with dogs

One hundred adults and 30 children completed questionnaires to investigate fear of dogs. Dog fearful adults asked to recall the origins of their fear reported classical conditioning experiences more frequently than vicarious acquisition or informational transmission. Overall, however, there was no difference in the frequency of attacks reported by the fearful and non-fearful groups. Significantly more fearful than non-fearful adults reported little contact with dogs prior to the onset of their fear which suggests that early non-eventful exposure to dogs may prevent a conditioning event from producing a dog phobia. Most adults reported that their fear began in childhood, and dog fear were more frequently reported by children than by adults. In the aggregate, however, dog-fearful adults and children differed in several ways; children were more likely than adults to report having received warnings about dogs, but also to recognize the potential attractiveness of a friendly dog. Unlike dog-fearful children, dog-fearful adults reported many other fears in addition to their fear of dogs. A better understanding of fear of dogs in adults may depend on discovering why some dog-fearful children, but not others, apparently lose their fear of dogs as they become older.

Comparison between FSS-II scores of two groups of university students sampled 15 yr apart

Undergraduate students were contacted in classes at Memorial University of Newfoundland during 1975 and asked to complete the FSS-II, on a voluntary basis; 511 students (232 male and 279 female subjects) provided enough data for analyses. In 1990, the same procedure was carried out, resulting in a comparable group of 359 students (161 male and 198 female subjects). Contrary to predictions, the 1990 students were more fearful than the 1975 group and the increase in fearfulness was contributed exclusively by women students. The component of fear contributing most to this increase related to social evaluation and violence.