H567/03 Section A - Affective, psychotic and anxiety disorders

Affective disorder: major depressive disorder

Affective disorders involve clinically significant disturbances of mood. Our sustained example is major depressive disorder (MDD), also called major depression or unipolar depression.

MDD involves persistent depressed mood or a marked loss of interest or pleasure, alongside other symptoms that cause significant distress or interfere with daily life. In a major depressive episode, the pattern lasts at least two weeks, with symptoms present for much of the day on most days. “Two weeks” is a necessary duration guide, rather than a rule that any sadness lasting two weeks is MDD. Clinical assessment also considers the wider symptom pattern and alternatives.

The characteristics span several domains:

People vary: one may sleep much more, another may be unable to sleep; not everyone displays every feature. Thoughts of death or suicide can occur, but are not present in every case. Such experiences require support from qualified services; classroom cases should never be used to classify oneself or a peer.

Unipolar describes depression without the manic or hypomanic episodes that characterise bipolar disorders. Mania involves unusually elevated or irritable mood and increased energy or activity, with features such as reduced need for sleep, rapid speech or risky behaviour. Bipolar disorder is therefore not simply another name for MDD or ordinary mood changes. Some depressive episodes include psychotic symptoms, so disorder classes are not perfectly separate boxes.

For a fictional example, Alex loses interest in music, feels persistently low, wakes early and struggles to concentrate at work for several weeks. Low mood and loss of pleasure fit the affective pattern; persistence and disrupted functioning add relevant evidence. A clinician would still investigate the history, physical illness, substances and any manic episodes before deciding on a diagnosis.

Psychotic disorder: schizophrenia

Psychotic disorders involve disruption in experiences such as perception, beliefs and thought. Schizophrenia is an example; it does not mean having a “split personality”.

Positive symptoms are experiences or behaviours added to ordinary functioning. The word does not mean beneficial. These can include hallucinations, delusions and disorganised thinking or speech. A hallucination is a perception-like experience without the corresponding external stimulus, such as hearing a voice others do not hear. A delusion is a firmly held false belief, such as believing a transmitter has been secretly implanted, that is not explained by the person's cultural setting. Disorganised speech may shift between ideas in a way that makes communication difficult.

Negative symptoms involve reductions in ordinary functioning. These can include reduced emotional expression, reduced speech, difficulty initiating or sustaining activities, withdrawal and reduced pleasure. “Negative” describes loss or reduction, rather than a judgement that the person is bad. Cognitive symptoms can involve problems with attention, memory and processing information, affecting tasks such as planning work.

Schizophrenia can interfere with relationships, education and self-care, but the course and severity vary. Many people improve with appropriate treatment and support. A diagnosis does not imply inevitable deterioration or violence. A person may have some ordinary experiences alongside periods of symptoms, which is why one calm conversation does not establish absence of a disorder.

A fictional case describes Sam hearing a commenting voice without an external speaker, holding a persistent belief that strangers control their thoughts, and struggling to organise conversation. These features fit a psychotic pattern. However, a clinician must consider persistence, impairment, cultural meaning and alternatives such as substances, medical conditions or a mood disorder with psychotic features. Hearing a voice alone cannot establish schizophrenia.