Learn Clinical psychology from scratch
1What clinical psychology does
Clinical psychology studies, assesses and treats psychological distress and mental disorders, such as anxiety, depression and psychosis.
A first question is what counts as abnormal. Four classic definitions each have a weakness:
- Statistical infrequency: behaviour that is rare. But some rare traits, such as a very high IQ, are not a problem.
- Deviation from social norms: behaviour that breaks a society’s rules. But norms differ between cultures and change over time.
- Failure to function adequately: being unable to cope with daily life.
- Deviation from ideal mental health: falling short of qualities such as self-acceptance and personal growth.
Disorders are classified in the DSM-5 (American Psychiatric Association) and the ICD-11 (World Health Organization). A diagnosis is reliable if different clinicians agree on it, and valid if it describes a real, distinct condition.
Prevalence is the proportion of a population that has a disorder at a given time. Incidence is the number of new cases in a period.
Most clinicians use a diathesis–stress or biopsychosocial view: a vulnerability (genes, early experience) combined with stress leads to a disorder.
Self-check A survey finds that 8% of adults in a town have depression this year. What does this figure describe?
- Incidence
- Prevalence
- Reliability
- Validity
Answer: Prevalence. It counts everyone who has the disorder in that period, old and new cases: prevalence. Incidence would count only the new cases.
2The main groups of disorders
Anxiety disorders share excessive fear and avoidance:
- Specific phobia: intense fear of one object or situation, such as spiders or heights.
- Social anxiety disorder: fear of being judged or embarrassed by others.
- Panic disorder: repeated unexpected panic attacks and worry about the next one.
- Agoraphobia: fear of situations where escape or help may be hard, such as buses, shops, queues or open spaces.
- Generalised anxiety disorder: ongoing, hard-to-control worry about many things.
Obsessive-compulsive disorder (OCD) has obsessions (unwanted, intrusive thoughts) and compulsions (repeated acts that reduce the anxiety). PTSD follows a traumatic event and lasts more than a month, with re-experiencing, avoidance, negative mood and hyperarousal.
Depression: a major depressive episode is low mood or loss of interest (anhedonia) for at least 2 weeks. In bipolar disorder there are episodes of mania, which last at least a week; hypomania is milder, lasts at least 4 days and causes no marked impairment or psychosis.
Schizophrenia lasts at least 6 months. Positive symptoms are added experiences: hallucinations (perceptions without a stimulus, such as hearing voices) and delusions (fixed false beliefs). Negative symptoms are losses, such as avolition (lack of motivation), alogia (little speech) and flat affect.
Other groups include eating disorders, personality disorders such as borderline personality disorder, and neurodevelopmental disorders such as autism spectrum disorder and ADHD.
Self-check Which of these is a negative symptom of schizophrenia?
- Avolition (lack of motivation)
- Believing you are being followed by spies
- Disorganised, jumbled speech
- Hearing voices that comment on your actions
Answer: Avolition (lack of motivation). Negative means something normal is missing, here motivation. Voices (hallucinations), persecutory beliefs (delusions) and disorganised speech are added experiences, so they are positive symptoms. “Negative” does not mean “unpleasant”.
3Explanations and treatments
Each approach explains disorders differently, and its treatment follows from that explanation:
- Behavioural: disorders are learned. Mowrer’s two-factor model says a phobia is acquired by classical conditioning (as in Little Albert) and maintained because avoidance reduces fear. Treatment: exposure therapy, systematic desensitisation, and exposure and response prevention for OCD.
- Cognitive: unhelpful thoughts cause distress. Beck’s cognitive triad in depression is negative views of the self, the world and the future. Ellis’s ABC model: an Activating event leads to emotional Consequences through Beliefs. Treatment: cognitive behavioural therapy (CBT).
- Humanistic: Rogers’ person-centred therapy offers empathy, genuineness and unconditional positive regard.
- Psychodynamic: unconscious conflicts and defence mechanisms, such as displacement (taking anger out on a safer target) and repression.
- Biological: genes, brain chemistry and structure. SSRIs block the reuptake of serotonin; antipsychotics block dopamine D2 receptors; lithium treats bipolar disorder; benzodiazepines enhance the effect of GABA.
Newer therapies include dialectical behaviour therapy (DBT), first developed for borderline personality disorder, and mindfulness-based cognitive therapy (MBCT), which helps prevent relapse in recurrent depression.
Self-check According to Mowrer’s two-factor model, what keeps a phobia going?
- Avoidance reduces anxiety, which negatively reinforces the avoidance
- Each meeting with the feared object adds more classical conditioning
- Low serotonin levels in the brain
- Unconscious conflict from childhood
Answer: Avoidance reduces anxiety, which negatively reinforces the avoidance. The phobia is learned by classical conditioning but maintained by operant conditioning: escaping brings relief, so avoidance is rewarded. Because the person never stays in the situation, the fear never fades.
4How to approach a clinical case
Case questions describe a person and ask for a diagnosis, an explanation or a treatment. Work in this order:
- List the symptoms and what the person fears or avoids.
- Note the duration and the effect on daily life, because many diagnoses depend on time limits.
- Match the pattern to a disorder, and rule out the nearest look-alike.
- Ask what maintains the problem, such as avoidance, safety behaviours or negative thoughts.
- Choose the treatment that targets that maintaining factor.
5A worked example
Follow the case one step at a time. Try to say the next step before you open it.
Worked exampleFor eight months, Lisa has had sudden panic attacks. She now avoids buses, supermarkets and queues because escape might be hard if she panics. When she must go out, she only goes with her sister. What is the likely diagnosis, what keeps it going, and which treatment fits?
1Repeated panic attacks, fear of several situations where escape is hard, avoidance of them, and needing a companion. It has lasted eight months and limits her life.
2Fear of two or more such situations because escape or help may be hard fits agoraphobia, here together with panic attacks.
3It is not social anxiety: she does not fear being judged. It is not a specific phobia: the fear covers several situations and is about panicking and not escaping.
4Avoidance and the safety behaviour (always going with her sister) bring short-term relief. This negatively reinforces them, and she never learns that she can cope alone.
5CBT with graded exposure: she faces the situations step by step, from easy to hard, and gradually drops the safety behaviours so the fear can fade.
Answer Agoraphobia with panic attacks, maintained by avoidance and safety behaviours; treated with CBT and graded exposure.
6Common mistakes
- Swapping hallucinations (false perceptions) and delusions (false beliefs).
- Thinking schizophrenia means a “split personality”. It is a psychotic disorder; it is not dissociative identity disorder.
- Reading “negative symptom” as “unpleasant symptom”. Negative means something normal is absent.
- Ignoring time limits: a depressive episode lasts at least 2 weeks, PTSD more than a month, schizophrenia at least 6 months.
- Thinking compulsions or avoidance are harmless relief. They reduce anxiety in the short term, which keeps the disorder going.
- Mixing up reliability (do clinicians agree?) and validity (is the diagnosis meaningful?).
Self-check A man hears a voice commenting on everything he does, though no one is there. What is this?
- A compulsion
- A delusion
- A negative symptom
- An auditory hallucination
Answer: An auditory hallucination. He perceives a sound without any stimulus, which is a hallucination. A delusion is a fixed false belief, such as being sure the neighbours are spying on him.
7How exam questions look
- Easy (key terms and facts): definitions. What a phobia, a hallucination or OCD is, what CBT focuses on, what prevalence means.
- Medium (applying the concepts): linking a theory or treatment to a disorder. Beck’s triad, the two-factor model, how SSRIs or benzodiazepines work, which diagnosis fits a short description.
- Hard (cases and analysis): a case or a study to evaluate. You choose between close diagnoses using duration and features, explain what maintains a problem, or judge evidence such as a waiting-list control.
For hard questions, check the duration and the exact fear or symptom first. Then ask what keeps the problem going; that usually points to the right treatment.
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