Mental Health & Disorders

Mental Health & Disorders

Anxiety Disorders

Anxiety disorders are the most common category of mental health conditions, affecting an estimated 30% of adults at some point in their lives. They involve excessive fear, worry, and related behavioural disturbances that are disproportionate to the actual threat and persist beyond developmentally appropriate periods. The neurobiology of anxiety involves hyperactivity in the amygdala (the brain's threat-detection centre), reduced inhibitory signalling from the prefrontal cortex, and dysregulation of the HPA axis (the body's stress-response system).

Generalised Anxiety Disorder (GAD) involves excessive, uncontrollable worry about a wide range of everyday matters - health, finances, work, relationships - for at least six months. The worry is accompanied by physical symptoms including muscle tension, fatigue, restlessness, irritability, and sleep disturbance. GAD often goes undiagnosed because the person has "always been a worrier."

Social Anxiety Disorder is an intense fear of being judged, rejected, or humiliated in social or performance situations. It goes beyond shyness - it can be debilitating, leading to avoidance of work, school, and relationships. Physical symptoms may include blushing, sweating, trembling, and a racing heart. It is one of the most commonly undiagnosed anxiety disorders.

Panic Disorder is characterised by recurrent, unexpected panic attacks - sudden surges of intense fear that peak within minutes, accompanied by physical symptoms such as chest pain, palpitations, shortness of breath, dizziness, derealisation, and a fear of dying or losing control. Many people with panic disorder develop agoraphobia, avoiding situations where escape might be difficult or help unavailable.

Specific Phobias are intense, irrational fears of particular objects or situations (heights, flying, spiders, enclosed spaces, blood, etc.) that lead to avoidance or endurance with extreme distress. They are highly treatable with exposure therapy, often in a single session for simple phobias. Across all anxiety disorders, CBT (particularly exposure-based approaches) and SSRI medications have the strongest evidence base.

Eating Disorders

Eating disorders involve severe disturbances in eating behaviour, body image, and weight-regulation behaviours. They have the highest mortality rate of any psychiatric illness - mortality from medical complications, suicide, and the long-term physical toll of malnutrition. An estimated 9% of the global population will experience an eating disorder in their lifetime, yet they remain under-diagnosed and under-treated, particularly in men, people of colour, and neurodivergent individuals.

Anorexia Nervosa is characterised by significantly low body weight, intense fear of gaining weight, and disturbance in the way one's body is experienced. Restriction may be severe enough to require medical hospitalisation. Anorexia has the highest mortality rate of any mental illness. Treatment often requires a multidisciplinary approach including medical monitoring, nutritional rehabilitation, and therapy (particularly Maudsley Family-Based Treatment for adolescents and CBT-E for adults).

Bulimia Nervosa involves cycles of binge eating (consuming a large amount of food with a sense of loss of control) followed by compensatory behaviours such as self-induced vomiting, laxative misuse, or excessive exercise. Weight is typically within or above the normal range, which can conceal the disorder. Bulimia is associated with dental erosion, electrolyte imbalances, and gastrointestinal damage. CBT-E (enhanced CBT) is the first-line treatment.

Binge-Eating Disorder (BED) involves recurrent binge eating without the compensatory behaviours seen in bulimia. It is the most common eating disorder and is strongly associated with obesity, though people across the weight spectrum can experience it. BED is characterised by eating rapidly, eating alone due to embarrassment, and feeling distressed after a binge. It responds well to CBT-E and interpersonal therapy.

Neurodivergence is significantly overrepresented in eating disorder populations. Autistic traits - sensory sensitivities around food, rigid eating routines, difficulty with interoceptive awareness (recognising hunger and fullness cues) - can both contribute to and be exacerbated by eating disorders. Adapted, neurodiversity-affirming approaches that accommodate sensory needs and communication differences are essential. ARFID (Avoidant/Restrictive Food Intake Disorder) is a separate diagnosis that often co-occurs with autism and involves restriction based on sensory sensitivity, fear of aversive consequences, or lack of interest in eating.

Mood Disorders

Mood disorders involve persistent disturbances in emotional state that affect cognition, behaviour, and physical functioning. They are among the most disabling health conditions worldwide and are highly responsive to treatment.

Major Depressive Disorder (MDD) is characterised by at least two weeks of persistent low mood or loss of interest or pleasure (anhedonia), accompanied by changes in appetite or weight, sleep disturbance, fatigue, psychomotor changes, feelings of worthlessness or guilt, difficulty concentrating, and recurrent thoughts of death or suicide. Depression is not just sadness - it is a systemic condition affecting energy, cognition, sleep, appetite, and the ability to experience pleasure. The cognitive triad (Beck) describes negative views of the self, the world, and the future. First-line treatments include CBT, behavioural activation, interpersonal therapy, and antidepressant medication (SSRIs and SNRIs). For treatment-resistant depression, options include transcranial magnetic stimulation (TMS), ketamine-assisted therapy, and electroconvulsive therapy (ECT). Lifestyle factors - exercise, sleep hygiene, nutrition, and social connection - play a significant role in both prevention and recovery.

Bipolar Disorder involves alternating episodes of depression and mania or hypomania. Bipolar I is defined by full manic episodes lasting at least one week or requiring hospitalisation - mania involves elevated or irritable mood, grandiosity, decreased need for sleep, pressured speech, racing thoughts, distractibility, increased goal-directed activity, and excessive involvement in risky behaviour. Bipolar II involves hypomanic episodes (less severe than full mania but still distinct from baseline) alternating with depressive episodes. Cyclothymia involves chronic fluctuations between hypomanic and depressive symptoms that do not meet full criteria for either. Bipolar disorder is strongly genetic and requires long-term management, typically with mood stabilisers (lithium, lamotrigine, valproate) and psychoeducation. Psychotherapy - particularly interpersonal and social rhythm therapy (IPSRT) and family-focused therapy - helps with medication adherence, early warning sign recognition, and lifestyle regularity.

Persistent Depressive Disorder (Dysthymia) is a chronic, lower-grade depression lasting at least two years. People with dysthymia may not realise they have been living with depression for so long that it feels like their personality. It is treatable with the same approaches as MDD, though the chronicity often requires longer-term intervention.

OCD

Obsessive-Compulsive Disorder involves a cycle of unwanted, intrusive thoughts, images, or urges (obsessions) and repetitive mental or behavioural acts performed to reduce the associated anxiety or prevent a feared event (compulsions). OCD is often trivialised as being "a bit OCD" about tidiness or organisation - in reality, it can be profoundly distressing and consume hours each day. Common obsession themes include contamination, symmetry, harm (fear of causing or failing to prevent harm), taboo thoughts (sexual, religious, or violent intrusions), and hoarding-related concerns.

OCD was historically classified as an anxiety disorder (and remains closely related) but has its own diagnostic category in the DSM-5 due to its distinct neurobiology and treatment needs. Neuroimaging shows hyperactivity in the orbitofrontal cortex, anterior cingulate cortex, and caudate nucleus - the cortico-striato-thalamo-cortical (CSTC) loop. This is why OCD feels like a "stuck" brain - the alarm system keeps firing even when the person knows the thought is irrational.

The gold-standard treatment is Exposure and Response Prevention (ERP), a specialised form of CBT in which the therapist guides the client to voluntarily confront obsession-triggering situations without performing the compulsion. Over time, the anxiety habituates, and the brain learns that the feared outcome does not occur. Acceptance and Commitment Therapy (ACT) and Inference-Based CBT are also effective, particularly for clients who struggle with ERP. Medication - SSRIs at higher doses than typically used for depression, or clomipramine - is also evidence-based, and the combination of medication and ERP is generally superior to either alone. OCD is highly comorbid with tic disorders, anxiety, depression, and autism - autistic OCD can present differently, often with more symmetry and ordering compulsions and less insight into the irrationality of the obsessions.

Personality Disorders

Personality disorders are defined by long-term, pervasive patterns of thinking, feeling, and behaving that deviate significantly from cultural expectations, cause distress or impairment, and are stable across time and situations. They typically emerge in adolescence or early adulthood. The DSM-5 organises them into three clusters: Cluster A (odd/eccentric - paranoid, schizoid, schizotypal), Cluster B (dramatic/emotional/erratic - antisocial, borderline, histrionic, narcissistic), and Cluster C (anxious/fearful - avoidant, dependent, obsessive-compulsive). Controversy surrounds the categorical model - many clinicians favour a dimensional approach (trait-based) as reflected in the alternative DSM-5 model, since these diagnoses carry significant stigma and show high comorbidity with each other.

Borderline Personality Disorder (BPD) is the most studied and treatable personality disorder. It is characterised by emotional dysregulation, unstable and intense relationships, frantic efforts to avoid abandonment, identity disturbance, impulsivity in areas like spending or substance use, recurrent suicidal behaviour or self-harm, chronic emptiness, and difficulty controlling anger. The biosocial model (Linehan) proposes that BPD develops when a biologically vulnerable person (high emotional sensitivity) grows up in an invalidating environment. DBT was specifically developed for BPD and is the gold-standard treatment, with strong evidence for reducing suicide attempts, hospitalisations, and self-harm. Mentalization-Based Treatment (MBT) and Transference-Focused Psychotherapy (TFP) are also evidence-based. BPD has historically been stigmatised even within mental health services, but the prognosis with appropriate treatment is good - most people with BPD show significant improvement over time.

Narcissistic Personality Disorder (NPD) involves grandiosity, need for admiration, and lack of empathy. Antisocial Personality Disorder (ASPD) involves disregard for and violation of the rights of others, often associated with conduct disorder in childhood. Avoidant Personality Disorder (AvPD) involves extreme social inhibition and sensitivity to rejection - it overlaps significantly with social anxiety but is more pervasive across contexts and resistant to safety behaviours. Obsessive-Compulsive Personality Disorder (OCPD) - distinct from OCD - involves preoccupation with orderliness, perfectionism, and control, without the intrusive obsessions and compulsive rituals that define OCD.

A neurodiversity-affirming lens is increasingly important in personality disorder work. Autistic burnout can mimic BPD symptoms, and autistic traits like sensory sensitivity, need for routine, and difficulty reading social cues can be mislabelled as personality pathology - what is sometimes called autistic masking collapse versus BPD. Differential diagnosis requires careful attention to developmental history and the context of the presenting behaviours.

Psychotic Disorders

Psychotic disorders involve profound alterations in perception, thought, emotion, and reality testing. The hallmark features are hallucinations (sensory experiences without external stimulus - most commonly auditory voices but can involve any sense), delusions (firmly held false beliefs not amenable to reason or evidence - paranoid, grandiose, somatic, referential, or bizarre), disorganised thinking and speech (tangentiality, loose associations, word salad), and negative symptoms (diminished emotional expression, avolition, social withdrawal, alogia). Cognitive impairment - in attention, memory, and executive function - is also common and often the most disabling dimension.

Schizophrenia affects approximately 1% of the population worldwide and typically emerges in late adolescence to early adulthood. It is not a split personality - that is a common misconception. The neurobiology involves dopamine dysregulation (the dopamine hypothesis), glutamate dysfunction, and structural brain changes including enlarged ventricles and reduced grey matter. Treatment is primarily with antipsychotic medication - first-generation (haloperidol, chlorpromazine) and second-generation (olanzapine, risperidone, clozapine) - combined with psychosocial interventions. Early intervention is critical: the duration of untreated psychosis is one of the strongest predictors of long-term outcome. Coordinated specialty care - including CBT for psychosis, family psychoeducation, supported employment, and peer support - significantly improves outcomes compared to medication alone.

Schizoaffective Disorder involves features of both schizophrenia and a mood disorder (major depressive or bipolar) occurring simultaneously. Delusional Disorder involves one or more non-bizarre delusions without the other hallmark symptoms of schizophrenia. Brief Psychotic Disorder involves sudden-onset psychotic symptoms lasting less than one month, often triggered by severe stress. Substance-Induced Psychotic Disorder can occur with stimulants, cannabis (particularly high-THC strains), hallucinogens, or steroid use. The trauma history of many people diagnosed with psychotic disorders is often overlooked - trauma-informed care is essential, as voices and paranoia are frequently linked to real experiences of abuse, neglect, or systemic violence.

PTSD & Complex PTSD

Post-Traumatic Stress Disorder develops after exposure to an actual or threatened traumatic event - death, serious injury, or sexual violence - either directly experienced, witnessed, or learned about. The DSM-5 organises PTSD symptoms into four clusters: intrusion (recurrent, involuntary memories, nightmares, flashbacks, and intense psychological or physiological distress at reminders), avoidance (of memories, thoughts, feelings, people, or places associated with the event), negative alterations in mood and cognition (persistent negative emotions, distorted blame of self or others, inability to remember key aspects, diminished interest in activities, detachment from others), and marked alterations in arousal and reactivity (irritability, angry outbursts, hypervigilance, exaggerated startle, difficulty concentrating, sleep disturbance, reckless or self-destructive behaviour).

Complex PTSD (C-PTSD) was added to the ICD-11 and results from prolonged, repeated, or inescapable trauma - particularly childhood abuse, domestic violence, torture, or captivity. In addition to the core PTSD symptoms, C-PTSD involves three further clusters: affect dysregulation (difficulty calming down, emotional numbness, intense emotional reactions to seemingly minor triggers), negative self-concept (feelings of worthlessness, shame, guilt, and a sense of being permanently damaged), and disturbances in relationships (difficulty trusting others, avoidance of intimacy, or preoccupation with and re-enactment of abusive dynamics). The distinction from BPD is debated - many overlap, but C-PTSD tends to have less fear of abandonment and more stable negative self-belief.

Evidence-based trauma treatments are trauma-focused and phase-oriented. Phase 1 focuses on stabilisation and safety - psychoeducation, grounding skills, emotion regulation, and building the therapeutic alliance before any memory processing. Phase 2 involves processing traumatic memories - EMDR (bilateral stimulation while recalling the traumatic memory), Prolonged Exposure (imaginal and in-vivo exposure to trauma reminders), Cognitive Processing Therapy (addressing stuck points and maladaptive beliefs), and Trauma-Focused CBT (particularly for children). Phase 3 focuses on integration and reconnection - consolidating gains, building a post-trauma identity, restoring relationships, and finding meaning. The central insight of trauma-informed care is that the body keeps the score: the trauma lives not just in memory but in the nervous system, and true healing must address the somatic, relational, and narrative dimensions of the wound.