Anxiety Disorders

Introduction

Anxiety disorders are characterised by excessive, persistent fear and anxiety that are Disproportionate to the actual threat and that significantly impair daily functioning. They are Among the most common mental disorders, affecting approximately 15—20% of the population at some Point in their lives. This section focuses on two specific anxiety disorders: phobias and Obsessive-compulsive disorder (OCD).

Phobias

A phobia is an irrational, persistent fear of a specific object, situation, or activity that leads To avoidance behaviour and significant distress or impairment. Phobias are classified into three Types:

• Specific phobias: Fear of specific objects or situations (e.g., arachnophobia — fear of spiders; acrophobia — fear of heights; claustrophobia — fear of enclosed spaces).
• Social phobia (social anxiety disorder): Fear of social situations in which the individual may be scrutinised, judged, or humiliated by others (e.g., public speaking, eating in public, meeting new people).
• Agoraphobia: Fear of open spaces, crowds, or situations from which escape might be difficult or embarrassing. Agoraphobia is frequently comorbid with panic disorder.

Biological Explanations of Phobias

Genetic factors: Family and twin studies suggest a moderate heritability for specific phobias (approximately 0.30—0.40). The heritability of blood-injection-injury phobias is particularly high (approximately 0.60), suggesting a strong genetic component for this specific subtype.

The preparedness hypothesis (Seligman, 1971): Seligman proposed that humans are biologically “prepared” to develop phobias of stimuli that were threats to survival during evolutionary history (e.g., snakes, spiders, heights, darkness, enclosed spaces). Prepared fears are acquired more Readily, are more resistant to extinction, and are more specific (they do not generalise to Similar stimuli) than non-prepared fears. The preparedness hypothesis explains why phobias are not Randomly distributed but cluster around a limited set of stimuli.

Evidence: Ohman and Mineka (2001) demonstrated that laboratory-reared monkeys acquired a fear of Snakes through observational learning (watching a model monkey react fearfully to a snake) but did Not acquire a fear of flowers using the same procedure. This demonstrates a biological Predisposition to learn certain fears more readily than others.

Behavioural Explanations of Phobias

Classical conditioning (Mowrer, 1947): Phobias are acquired through classical conditioning. A Neutral stimulus (e.g., a dog) is paired with an aversive unconditioned stimulus (e.g., being Bitten), resulting in a conditioned fear response to the previously neutral stimulus.

Stimulus generalisation: The conditioned fear response may generalise to stimuli similar to the Original conditioned stimulus. For example, a fear of one specific dog may generalise to all dogs, Or even to all furry animals.

Operant conditioning (negative reinforcement): Phobias are maintained through negative Reinforcement. Avoiding the feared stimulus reduces anxiety, which reinforces the avoidance Behaviour. Each time the individual avoids the feared stimulus, the avoidance is reinforced, making It harder to overcome the phobia.

Evaluation of behavioural explanations:

• Classical conditioning can explain how phobias are acquired, but many people with phobias cannot recall a specific conditioning event. This suggests either that conditioning occurred without conscious awareness or that other mechanisms (e.g., biological preparedness, vicarious learning) are also involved.
• The behavioural explanation does not fully account for why phobias of certain stimuli are much more common than phobias of other stimuli that are objectively more dangerous (e.g., many more people have phobias of snakes than of cars or electricity, despite the latter being far more dangerous).

Cognitive Explanations of Phobias

Cognitive explanations focus on how maladaptive thought patterns and attentional biases maintain Phobias.

Selective attention: Individuals with phobias selectively attend to threat-related stimuli in The environment. For example, individuals with spider phobias detect spiders in visual displays more Quickly than non-phobic individuals (Ohman et al., 2001).

Cognitive biases: Phobic individuals interpret ambiguous stimuli as threatening (e.g., Interpreting a rustling sound as a snake), overestimate the probability of harm, and catastrophise The consequences of encountering the feared stimulus.

Evaluation: Cognitive biases may be a consequence rather than a cause of phobias. It is possible That the fear response creates the cognitive bias, rather than the cognitive bias causing the fear Response.

Treatment of Phobias

Systematic desensitisation (Wolpe, 1958): Developed by Joseph Wolpe, systematic desensitisation Is based on the principle of reciprocal inhibition — the idea that anxiety cannot coexist with a State of relaxation. The treatment involves three steps:

1. Construction of an anxiety hierarchy: The client and therapist construct a ranked list of fear-provoking situations, from least to most anxiety-provoking.
2. Relaxation training: The client learns relaxation techniques (deep breathing, progressive muscle relaxation).
3. Gradual exposure: The client is gradually exposed to the feared stimuli while remaining relaxed, working through the anxiety hierarchy from least to most anxiety-provoking.

Ost (1989): Conducted a meta-analysis of studies on systematic desensitisation and found that it Was effective for approximately 80—90% of individuals with specific phobias. The treatment was Effective across different types of phobias and different delivery methods (in vivo, imaginal, and Virtual reality exposure).

Evaluation: Systematic desensitisation is effective, well-supported by evidence, and relatively Non-invasive. However, it requires significant motivation and effort from the client, and some Individuals may drop out of treatment before completing the hierarchy.

Flooding: A more intensive form of exposure therapy in which the client is directly exposed to The most feared stimulus (the top of the anxiety hierarchy) without relaxation training. Flooding Produces rapid extinction of the fear response through habituation (the client learns through Repeated exposure that the feared stimulus is not dangerous). Flooding is effective but can be Highly distressing and raises ethical concerns.

Obsessive-Compulsive Disorder (OCD)

OCD is characterised by:

• Obsessions: Recurrent, intrusive, and distressing thoughts, images, or urges that the individual recognises as irrational (e.g., fear of contamination, intrusive violent or sexual thoughts, fear of causing harm).
• Compulsions: Repetitive behaviours or mental acts that the individual feels driven to perform in response to an obsession or according to rigid rules (e.g., hand washing, checking locks, counting, arranging objects symmetrically).

OCD is highly distressing and time-consuming, often consuming several hours per day, and Significantly impairs social, occupational, and academic functioning.

Biological Explanations of OCD

Genetic factors: OCD has a heritability of approximately 0.40—0.50. First-degree relatives of Individuals with OCD are approximately 4 times more likely to develop OCD than the general Population.

Neurotransmitter abnormalities: The serotonin hypothesis of OCD proposes that OCD is caused by Dysregulation of the serotonin system. This is supported by the effectiveness of SSRIs (particularly Clomipramine, which is a tricyclic antidepressant with strong serotonergic effects) in treating OCD.

Neural circuit abnormalities: Neuroimaging studies have consistently implicated dysfunction in The cortico-striato-thalamo-cortical (CSTC) circuit in OCD. Specifically:

• Hyperactivity of the orbitofrontal cortex (OFC): The OFC is involved in error detection and the evaluation of the significance of stimuli. Hyperactivity of the OFC may cause individuals with OCD to assign excessive significance to normally irrelevant stimuli (e.g., a small spot of dirt on the hand), triggering obsessions.
• Hyperactivity of the caudate nucleus: The caudate nucleus (part of the striatum) acts as a “filter” that suppresses unwanted thoughts and behaviours. In OCD, caudate dysfunction may fail to filter out intrusive thoughts, allowing them to enter consciousness as obsessions.
• The thalamus acts as a relay station in the CSTC circuit, and its dysfunction contributes to the persistence of obsessive thoughts.

Evaluation of biological explanations:

• The serotonin hypothesis is supported by the effectiveness of SSRIs, but not all patients respond to SSRIs, suggesting that serotonin is not the only factor involved. Some patients with OCD respond to antipsychotic medication (which primarily targets dopamine), suggesting a role for dopamine dysfunction as well.
• The CSTC circuit model is supported by consistent neuroimaging findings and provides a plausible neural mechanism for OCD symptoms.

Behavioural Explanation of OCD

Two-process model (Mowrer, 1960): OCD is acquired and maintained through a combination of Classical and operant conditioning:

1. Acquisition (classical conditioning): A neutral stimulus (e.g., touching a doorknob) becomes associated with fear through pairing with a fear-inducing event (e.g., hearing about a disease outbreak). The doorknob becomes a conditioned stimulus that triggers anxiety (conditioned response).
2. Maintenance (operant conditioning): The compulsive behaviour (e.g., hand washing) reduces the anxiety caused by the obsession. This negative reinforcement strengthens the association between the obsession and the compulsion, making the compulsion more likely to be performed in the future.

Evaluation:

• The two-process model explains how compulsions are maintained through negative reinforcement.
• However, it cannot explain why obsessions occur in the first place (most people experience intrusive thoughts but do not develop OCD) or why some individuals develop OCD without any identifiable conditioning event.

Cognitive Explanation of OCD

Salkovskis (1985): Salkovskis proposed that OCD is maintained by maladaptive interpretations of Normal intrusive thoughts. Everyone experiences intrusive thoughts from time to time (e.g., “What if I left the stove on?”), but most people dismiss these thoughts as unimportant. Individuals with OCD Interpret their intrusive thoughts as highly significant, dangerous, and indicative of personal Responsibility (e.g., “If I have this thought about harming someone, it means I am a dangerous Person and must take action to prevent it”).

Key cognitive distortions in OCD:

• Thought-action fusion: The belief that having a thought is morally equivalent to performing the action, or that thinking about an event increases its probability of occurring.
• Inflated responsibility: The belief that one has a disproportionate responsibility for preventing harm.
• Intolerance of uncertainty: The belief that any possibility of harm is unacceptable and must be eliminated.
• Perfectionism: The belief that mistakes are catastrophic and must be avoided at all costs.

Evaluation:

• Cognitive models explain why obsessions are distressing (they are interpreted as significant and threatening) and why compulsions are performed (to reduce the perceived threat).
• The model is supported by experimental studies showing that manipulating responsibility appraisals increases compulsive behaviour (Lopatka and Rachman, 1995).

Treatment of OCD

Drug therapy: SSRIs (particularly clomipramine and fluoxetine) are the first-line Pharmacological treatment for OCD. They are effective for approximately 60% of patients, but the Required doses are higher than those used for depression, and the onset of therapeutic Effects is slower (10—12 weeks).

CBT for OCD: The most effective psychological treatment for OCD is exposure and response Prevention (ERP), a specific form of CBT. ERP involves:

1. Exposure: The client is gradually exposed to stimuli that trigger obsessions.
2. Response prevention: The client is prevented from performing the compulsive behaviour.

Through repeated exposure without compulsive response, the client learns that the feared consequence Does not occur (habituation), and the association between the obsession and anxiety weakens (extinction).

Marks (1981): Conducted a meta-analysis comparing exposure therapy, antidepressant medication, And their combination for OCD. Exposure therapy (particularly ERP) was found to be at least as Effective as medication, and the combination of exposure and medication was the most effective Treatment. However, relapse rates were higher for medication-only treatment after discontinuation, While the gains from exposure therapy were more durable.

For an overview of abnormal psychology topics, see Abnormal Psychology.

Common Pitfalls

1. Failing to discuss ethical issues (informed consent, deception, debriefing, right to withdraw) when evaluating studies.

2. Confusing correlation and causation in psychological research evidence.

3. Presenting theories without the supporting empirical evidence that led to their acceptance.

4. Confusing the approaches (biological, cognitive, behavioural, psychodynamic, humanistic) and their key assumptions.

Summary

The key principles covered in this topic are linked in the sub-pages above. Focus on understanding the definitions, applying the formulas or frameworks, and evaluating strengths and limitations of each approach.

Worked Examples

Worked examples demonstrating the application of key concepts are covered in the detailed sub-pages linked above.