More psychologists are involved in the diagnosis and treatment of psychological disorder than in any other aspect of psychology.
About 10% to 15% of Canadians are estimated to be affected by a psychological disorder during any one year. The impact of mental illness is particularly strong on people who are poorer, of lower socioeconomic class, and from disadvantaged ethnic groups.
A psychological disorder is an unusual, distressing, and dysfunctional pattern of thought, emotion, or behaviour. Psychological disorders are often comorbid, meaning that a given person suffers from more than one disorder.
The stigma of mental disorder affects people while they are ill, while they are healing, and even after they have healed. But mental illness is not a fault, and it is important to work to help overcome the stigma associated with disorder.
All psychological disorders are determined by multiple biological, psychological, and social factors.
Psychologists diagnose disorder using the Diagnostic and Statistical Manual of Mental Disorders (DSM). The DSM organizes the diagnosis of disorder according to five dimensions (or axes) relating to different aspects of disorder or disability. The DSM uses categories, and patients with close approximations to the prototype are said to have that disorder.
One critique of the DSM is that many disorders — for instance, attention-deficit/hyperactivity disorder (ADHD), autistic disorder, and Asperger’s disorder — are being diagnosed significantly more frequently than they were in the past.
Anxiety disorders are psychological disturbances marked by irrational fears, often of everyday objects and situations. They include generalized anxiety disorder (GAD), panic disorder, phobia, obsessive-compulsive disorder (OCD), and post-traumatic stress disorder (PTSD). Anxiety disorders affect about 350,000 Canadians every year.
Dissociative disorders are conditions that involve disruptions or breakdowns of memory, awareness, and identity. They include dissociative amnesia, dissociative fugue, and dissociative identity disorder.
Mood disorders are psychological disorders in which the person’s mood negatively influences his or her physical, perceptual, social, and cognitive processes. They include dysthymia, major depressive disorder, and bipolar disorder. Mood disorders affect about 5% of Canadians every year.
Schizophrenia is a serious psychological disorder marked by delusions, hallucinations, loss of contact with reality, inappropriate affect, disorganized speech, social withdrawal, and deterioration of adaptive behaviour. About 350,000 Canadians have schizophrenia.
A personality disorder is a long-lasting but frequently less severe disorder characterized by inflexible patterns of thinking, feeling, or relating to others that causes problems in personal, social, and work situations. They are characterized by odd or eccentric behaviour, by dramatic or erratic behaviour, or by anxious or inhibited behaviour. Two of the most important personality disorders are borderline personality disorder (BPD) and antisocial personality disorder (APD).
Somatization disorder is a psychological disorder in which a person experiences numerous long-lasting but seemingly unrelated physical ailments that have no identifiable physical cause. Somatization disorders include conversion disorder, body dysmorphic disorder (BDD), and hypochondriasis.
Patients with factitious disorder fake physical symptoms in large part because they enjoy the attention and treatment that they receive in the hospital.
Sexual disorders refer to a variety of problems revolving around performing or enjoying sex. Sexual dysfunctions include problems relating to loss of sexual desire, sexual response or orgasm, and pain during sex.
Gender identity disorder (GID, also called transsexualism) is diagnosed when the individual displays a repeated and strong desire to be the other sex, a persistent discomfort with one’s sex, and a belief that one was born the wrong sex, accompanied by significant dysfunction and distress. The classification of GID as a mental disorder has been challenged because people who suffer from GID do not regard their own cross-gender feelings and behaviours as a disorder and do not feel that they are distressed or dysfunctional.
A paraphilia is a sexual deviation where sexual arousal is obtained from a consistent pattern of inappropriate responses to objects or people, and in which the behaviours associated with the feelings are distressing and dysfunctional.