Introduction to Psychological Disorders
Senior 6 · Psychology
Introduction to Psychological Disorders
Lesson 5 of 5
25 min
Depression and panic usually come in episodes, with periods of being well in between. Some difficulties are different: they are woven into how a person habitually thinks, feels and relates to others, from adolescence onwards. Other problems are defined less by inner suffering than by behaviour that harms the person or breaks society's rules: drinking that is out of control, gambling away a family's savings, persistent delinquency. This lesson covers three groups of conditions that raise hard questions about where personality ends and disorder begins, and where disorder ends and crime begins.
Definition
Personality disorder (DSM-5-TR, summarised): an enduring pattern of inner experience and behaviour that differs markedly from the expectations of the person's culture, is inflexible and pervasive across situations, begins by adolescence or early adulthood, is stable over time, and causes distress or impairment.
Psychosexual disorders: problems of sexual functioning, or sexual interests that cause the person distress or harm others. Today they are classed as sexual dysfunctions and paraphilic disorders.
Psychosocial deviance: behaviour that breaks important social norms and harms the person or others, such as substance misuse, gambling, delinquency and violence. Deviance alone is not a mental disorder; some deviant behaviour is linked to disorders such as substance use disorder or conduct disorder.
Substance use disorder: a pattern of using alcohol or another drug that leads to significant problems: loss of control over use, neglect of responsibilities, risky use, and often tolerance and withdrawal.
The DSM-5-TR lists ten personality disorders in three clusters (Figure 1). Worldwide, about 8% of adults may meet the criteria for at least one (Winsper and others, 2020).
Figure 1. The three clusters of personality disorders in the DSM-5-TR. Memory hook: A is "weird", B is "wild", C is "worried".
Evaluation. The categories overlap heavily, many people fit several, and the label "personality disorder" is easily heard as "bad person", which adds stigma. The WHO's ICD-11 (2022) therefore replaced the separate types with one diagnosis rated by severity (mild, moderate, severe), described by trait domains: negative affectivity, detachment, dissociality, disinhibition and anankastia (rigid perfectionism), with an optional borderline pattern. This dimensional approach fits the evidence that personality varies continuously rather than in boxes.
This topic is taught at textbook level, with respect.
Two facts must be clear. First, any sexual contact with a child is abuse and a crime; a diagnosis never excuses it, and the responsibility always lies with the adult. If you or a child you know is at risk, tell a trusted adult or call the free numbers listed by the Rwanda Investigation Bureau (RIB): 116, 3512, 3029 or 166. Second, classifications change as evidence grows: homosexuality was removed from the DSM in 1973 and from the WHO's ICD in 1990, and in ICD-11 "gender incongruence" was moved out of the chapter on mental disorders into a chapter on sexual health.
| Deviance | When it becomes a disorder | Main contributing factors |
|---|---|---|
| Alcohol and drug misuse | Substance use disorder: loss of control, neglect of duties, risky use, cravings, tolerance and withdrawal, over twelve months | Genes; the brain's reward (dopamine) system; peers and availability; using substances to cope with stress or trauma |
| Gambling, including betting on phones | Gambling disorder: chasing losses, lying about gambling, borrowing to gamble, damage to family and studies | Unpredictable rewards (a variable-ratio schedule, the strongest form of operant reinforcement); easy access; false beliefs about "luck" |
| Delinquency and antisocial behaviour | Conduct disorder in under-18s: a persistent pattern of aggression, destruction, deceit or serious rule-breaking | Harsh or inconsistent parenting, abuse, poverty, deviant peers, school failure, and temperament |
The WHO (2024) estimated that alcohol caused 2.6 million deaths worldwide in 2019. Terrie Moffitt's (1993) research on a large New Zealand birth cohort distinguishes adolescence-limited antisocial behaviour, which is common, linked to peers and usually stops in early adulthood, from life-course-persistent antisocial behaviour, which is rare, starts in early childhood and is linked to early difficulties and adversity. The distinction matters for prevention: most young offenders grow out of it, especially with school, work and supportive relationships, while a small group needs early, intensive help for the child and family.
CrashCourse: "Personality Disorders: Crash Course Psychology #34" (about 10 minutes). It explains the three clusters, with a closer look at antisocial and borderline personality disorder. Note what it says about the causes and the treatment of each.
Important
If a child is being abused, report it. Talk to a trusted adult and call the free Rwanda Investigation Bureau lines: 116 to report child abuse, 3512 for domestic or gender-based violence, 3029 for the Isange One Stop Centre, or 166 in an emergency. For help with alcohol, drugs, gambling or distress, visit your health centre or call RBC's toll-free number 114.
Warning
Do not use diagnoses as insults. Calling a classmate a "psychopath" or "narcissist" is unkind and almost always wrong. And remember that most people with a personality disorder or a substance use disorder are struggling, not wicked: these conditions are treatable, and recovery is common.
Tip
A is weird, B is wild, C is worried. For the deviances, learn Moffitt's two pathways by their timing: adolescence-limited (starts and stops in the teens) versus life-course-persistent (starts early, continues).
Practice
Further reading
Sources and credits
Written by Ganzaa: the text, the diagram (Figure 1), the table and the exercises.
