Depression is not simply sadness, lack of willpower or the result of one single “chemical cause”. It is a heterogeneous mental health condition that can involve changes in mood, loss of interest or pleasure, exhaustion, altered sleep and appetite, more negative or rigid thinking, withdrawal, difficulty concentrating and meaningful impairment in everyday life. Understanding what may have triggered it and what is keeping it going in a particular person is an important part of treatment.
In clinical work, one of the questions I hear most often is not simply “Do I have depression?” It is usually closer to: “Is what I am going through really depression, or should I just be coping better?” There is already a great deal of suffering hidden in that question. The person is not only struggling; they are also judging themselves for struggling.
Depression can make things that used to happen almost automatically — getting out of bed, showering, replying to a message, concentrating, preparing food, going to work or meeting someone — begin to require an extraordinary amount of effort. Because these tasks may look simple from the outside, the difficulty is easily mistaken for laziness, indifference or lack of motivation. Clinically, we need to look at something much broader: what has changed, how much it is interfering, how mood, thinking and behaviour interact, what is happening in the person’s life and whether there are safety concerns.
This guide is intended to be Ocnos Psychology Clinic’s central resource on depression. It is not designed to turn every period of sadness into a diagnosis, nor to replace an individual assessment. Its aim is to explain depression accurately enough to help you make sense of what may be happening and know which questions are worth asking.
If there is immediate risk: if you or someone close to you may act on suicidal thoughts, cannot stay safe, has severe self-neglect or is in immediate danger, seek urgent help. In Spain, call 112 or the national suicide support line 024. In Gibraltar, the GHA Mental Health Crisis Service is available 24/7 on 111; in an emergency call 999.
What is depression?
Depression is a mental disorder that can affect mood, the ability to experience interest or pleasure, energy, thinking, the body, sleep, appetite, relationships and day-to-day functioning. The World Health Organization distinguishes depression from ordinary changes in mood and notes that effective treatments exist for mild, moderate and severe presentations.
One useful way of understanding depression is as a loss of flexibility. In ordinary sadness, however painful it may be, there are often still moments of connection, interest, hope or emotional response to what is happening around us. In depression, the problem may become more global: the person does not only feel bad; they begin to lose access to activities, relationships and expectations that previously gave shape to their life.
This does not mean that every depression looks the same. Some people cry easily; others say they can hardly feel anything. Some barely sleep; others could spend most of the day in bed. Some lose their appetite; others eat more. Some look visibly distressed, while others continue working and smiling despite functioning at an enormous internal cost.
Depression is not simply feeling sad
Sadness is a normal human emotion. It can follow loss, disappointment, relationship breakdown or a difficult period, and it does not have to become an illness in order to deserve care and respect. Feeling sad does not automatically mean that someone is depressed.
In depression, we usually see a broader shift. The issue is not only how painful the experience is, but how many areas of life have become caught up in it: getting out of bed, thinking clearly, enjoying things, caring for the body, maintaining routines, working, studying, relating to others or imagining a different future.
Anhedonia is particularly important: a marked reduction in the ability to enjoy or feel interested in things that used to matter. It is not always experienced as sadness. People may describe it as “nothing really reaches me”, “I know I used to enjoy this, but now I feel nothing” or “I am doing everything on autopilot”.
Two weeks is not a magical boundary. Some diagnostic criteria use a minimum period of around two weeks when defining a depressive episode, but that does not mean you should wait fourteen days before asking for help if your functioning has deteriorated significantly. Nor does it mean that every difficult period lasting two weeks is automatically depression.
What are the symptoms of depression?
Depression can affect several domains at once. You do not need to experience every symptom, and the pattern varies considerably from one person to another.
Mood
Persistent low mood, emptiness, hopelessness, irritability, emotional disconnection or difficulty feeling relief.
Interest and pleasure
Loss of motivation, reduced enjoyment and withdrawal from hobbies, relationships or activities that previously had meaning.
Energy and movement
Marked fatigue, slowing down, a sense of heaviness or, in some people, difficult-to-control restlessness and agitation.
Thinking
Difficulty concentrating or deciding, rumination, harsh self-criticism, guilt, hopelessness or feelings of worthlessness.
Sleep and appetite
Insomnia or sleeping excessively, changes in appetite or weight, disrupted routines and sleep that does not feel restorative.
Functioning and relationships
Isolation, reduced self-care, problems at work or in education, cancelling plans and difficulty maintaining everyday responsibilities.
Thoughts about death or suicide may occur in some depressive episodes. They are not required for depression to be severe and, when present, they need specific assessment. A symptom questionnaire is not a substitute for a suicide risk assessment.
What causes depression? There is no single explanation
Looking for the cause of depression often leads to explanations that are too simple. Research describes depression as a multifactorial and heterogeneous condition. Biological and genetic vulnerabilities, early experiences, loss, chronic stress, physical health, patterns of thinking and behaviour, relationships and social conditions can interact in different ways.
This matters because it helps us avoid two common forms of reductionism: the idea that depression is entirely “in the mind” and therefore a matter of attitude, or the idea that it can always be explained by one isolated chemical abnormality. Antidepressants can affect neurobiological systems, but that does not make depression a simple “serotonin deficiency”. Equally, the fact that thoughts can be worked with therapeutically does not mean someone became depressed because they “thought wrongly”.
Biological vulnerability
Genetics can contribute to risk, as can neurobiological processes, sleep and circadian disruption, physical illness, chronic pain, hormonal changes, some medications and substance use.
Life experience and stress
Bereavement, trauma, violence, conflict, unemployment, financial pressure, illness, loneliness, caring responsibilities or major life transitions can place significant strain on a vulnerable person.
Cognitive processes
Harsh self-criticism, hopelessness, rumination and certain schemas can influence how experiences are interpreted and how easily positive or corrective information is taken in.
Behavioural processes
Withdrawing, avoiding, giving up meaningful activity or losing contact with sources of support and reward can help maintain depression, even when those behaviours originally developed as understandable attempts to reduce distress.
Interpersonal processes
Isolation, conflict, loss of support, rejection sensitivity and difficult relationship patterns may act as risk factors, consequences or maintaining factors.
Social context
Housing, discrimination, financial insecurity, work conditions, access to care and social support all matter. Depression does not occur outside the person’s actual life.
How depression can keep going even though nobody chooses it
One of the most useful ideas in behavioural activation is the distinction between the problems that contribute to feeling low and the coping strategies that are understandable in the short term but may gradually make life narrower.
Imagine someone loses their job. They feel ashamed, exhausted and worried. To avoid questions, they stop seeing friends. Because sleep has deteriorated, they get up later and later. Putting off job applications reduces anxiety for a few hours. Over time, however, there is less social contact, less structure, less sense of competence and greater financial pressure. What brought short-term relief begins to carry a long-term cost.
Martell, Dimidjian and Herman-Dunn describe this kind of cycle in behavioural activation: life changes may reduce rewarding experiences or increase punishment, while avoidance and withdrawal can bring immediate relief and at the same time progressively reduce contact with the world. This does not mean the person is “maintaining their depression on purpose”. It means that a strategy that made sense initially may stop helping.
Depression can also change how events are interpreted
Beck’s cognitive model proposes that, during depression, negative views of the self, the world and the future may become especially accessible. This is more than simply “having negative thoughts”. Certain interpretations can feel extraordinarily convincing at the very time when the person has less energy and fewer experiences that might challenge them.
“I made a mistake” can become “I am a failure”. “I could not get up today” can become “I will never be myself again”. “My friend has not replied” may feel like “Nobody cares about me any more”. When mood is very low, these conclusions can feel like facts rather than interpretations.
Cognitive therapy is not about replacing every “negative” thought with a positive slogan. The second edition of Beck and colleagues’ manual places strong emphasis on understanding the personal meaning of thoughts, the emotion linked to them, and testing interpretations collaboratively through evidence and experience.
Rumination: thinking a lot is not always the same as solving a problem
Rumination is repetitive thinking that keeps circling around distress: “Why am I like this?”, “What is wrong with me?”, “How did I end up here?”, “What if I never change?”. It can feel as though the mind is trying to solve something, but often it consumes attention without moving the person towards a useful action.
Rumination and withdrawal can reinforce one another. The less contact there is with the outside world, the more space may be available for repetitive self-focused thinking; the more someone ruminates, the harder it can become to start an activity, ask for help or test whether a negative prediction is actually accurate.
That is why some treatments do not try to “win” an argument with every thought. They may instead help the person notice when thinking is genuinely helping them solve a problem and when it has become another way of getting stuck.
Depression does not always look like depression: what “high-functioning depression” means
Terms such as “high-functioning depression”, “hidden depression” or “masked depression” are widely used online, but they are not formal diagnoses in themselves. They can be useful shorthand for situations in which someone maintains an outward appearance of functioning while experiencing significant depressive symptoms internally.
A person may continue working, caring for their family, making jokes or meeting responsibilities and still come home completely depleted, live with little or no pleasure, withdraw emotionally or experience profound hopelessness. Visible functioning is one part of assessment; it is not proof that depression is absent.
How to tell depression from sadness, grief or exhaustion
The boundaries are not always neat, which is why a clinical assessment is usually more useful than matching yourself against a single checklist.
Sadness
Sadness is a normal emotion, usually connected to something that has happened. It can be intense without becoming a mental disorder, particularly when the capacity to function and connect remains relatively intact.
Grief
Bereavement can involve profound pain, longing, sleep disruption and major changes in everyday life. Grief and depression can share features and can also coexist. Context and the pattern of symptoms matter.
Stress and exhaustion
A chronically overloaded person may become tired, irritable and detached. If loss of pleasure, hopelessness and impairment spread well beyond the stressful context, depression should be considered.
Depression
The pattern is usually broader and more persistent, with changes in mood or pleasure alongside other symptoms and meaningful impairment in day-to-day functioning.
If emotional emptiness is the main problem and you are not sure how to understand it, you may also find our guide “I have friends, a partner or a job… but I still feel empty inside” useful.
Unipolar depression and bipolar depression: why the whole history matters
A depressive episode can occur within a unipolar depressive disorder or as part of bipolar disorder. During a depressive phase, someone may seek help only for apathy, sadness, hopelessness or low energy and may not consider earlier periods of unusually high energy, reduced need for sleep, intense activity, impulsivity or disinhibition relevant.
The distinction matters because it changes clinical formulation and treatment. A careful assessment therefore asks not only “How do you feel now?”, but also about previous episodes and periods when mood or activation were markedly different from the person’s usual baseline.
Recurrent, persistent and severe depression are not the same thing
Depression can be described in terms of both course and severity. An episode may be less severe or more severe; it may be a first episode or part of a recurrent pattern; and some people experience symptoms over a long period of time.
Duration, recurrence and severity answer different clinical questions. A long-lasting depression is not automatically the most severe at any particular moment, while a relatively recent episode may require urgent attention if there is severe impairment or high risk.
Psychotic symptoms, significant suicide risk, severe self-neglect or inability to meet basic needs all change the level of care required. Our separate guide on what makes depression severe explains these distinctions in more detail.
How is depression diagnosed?
Depression should not be diagnosed by adding up a questionnaire score and stopping there. Questionnaires can be useful for detecting symptoms and monitoring change, but diagnosis requires clinical information to be interpreted together.
A useful assessment usually explores:
- Current symptoms: mood, anhedonia, energy, sleep, appetite, concentration, guilt, movement and thoughts of death.
- Functioning: what has changed in work, education, self-care, relationships, parenting and everyday responsibilities.
- Duration and course: when it started, how it has changed and whether there have been previous episodes.
- Risk: suicidal thoughts, intent, self-harm, self-neglect and the ability to remain safe.
- Previous periods of unusually high activation: possible hypomanic or manic episodes.
- Physical health: illness, pain, sleep, medication and other relevant medical factors.
- Alcohol and other substances.
- Context: loss, stress, violence, relationships, support, housing, finances and current demands.
- Previous treatment: what has been tried, for how long, what helped and what adverse effects occurred.
Tools such as the PHQ-9 may support screening or routine outcome monitoring. The BDI-II and other clinical scales can also provide useful information, but no score on its own replaces a clinical interview or automatically determines treatment.
If you are looking for a first point of reflection, Ocnos also offers an indicative depression symptoms self-check. It is designed to help you organise what you are noticing, not to diagnose you.
Private tool: map the cycle that may be keeping you stuck
This exercise is inspired by principles of behavioural activation, but it does not reproduce a clinical questionnaire and it does not calculate a depression score. It is simply a way to notice a possible cycle between context, avoidance, immediate relief and longer-term cost.
What helps me escape today but may be narrowing my life tomorrow?
🔒 Private. Your answers remain only on this device. They are not sent to Ocnos, not stored in a database and disappear if you leave or refresh the page. This tool does not diagnose depression and should not be used during an emergency.
How is depression treated?
There is no single treatment that fits everyone. NICE recommends matching treatment to the person’s clinical needs, preferences, previous treatment and current circumstances. Evidence-based psychological interventions include cognitive behavioural therapy, behavioural activation and other structured therapies, with interpersonal approaches also appropriate in some cases.
For more severe depression, antidepressant medication, psychological therapy or a combination may be considered, and some presentations require coordination with a GP or psychiatrist. Psychotic symptoms, significant suicide risk or severe physical deterioration change the level of support required.
Good treatment should not be reduced to generic advice such as “exercise”, “get out more” or “think positively”. Behaviour can be therapeutically important, but it needs to become an individualised plan: small enough to be achievable and connected strongly enough to the person’s real life to matter.
What behavioural activation adds
Behavioural activation starts from a practical observation: when depression leads someone to withdraw from life, waiting to feel fully motivated before acting can prolong the standstill. Therapy looks at which activities have disappeared, where avoidance has developed and which actions are most likely to restore structure, problem-solving, connection or meaningful experience.
This does not mean filling a diary or forcing yourself to stay busy. Martell and colleagues emphasise that goals need to be individualised. The question is not “How do we make this person do more things?” but “What do they want to regain, and which behaviours could move them towards a life that feels more connected with what matters?”.
For one person, the first therapeutic step may be getting up, showering and eating breakfast at an agreed time. For someone else, it may be a ten-minute walk. For another, replying to one message. The size of the action depends on the starting point.
What cognitive therapy adds
Cognitive therapy helps people identify the interpretations that accompany emotion and examine whether those interpretations are sufficiently accurate and useful. It is not about persuading someone that “everything will be fine”. It uses questions, evidence, behavioural experiments and alternative perspectives when thinking has become excessively rigid or biased.
Beck and colleagues also stress that behavioural strategies are an integral part of cognitive therapy, particularly when motivation is very low. Thought, emotion and behaviour influence one another; treatment can intervene from more than one direction.
A simple clinical example: “I performed less well today” is not the same statement as “I am incapable of doing my job”. The first describes a specific event; the second turns one difficult day into a stable identity. Therapy does not erase real problems. It helps separate the problem, the interpretation and the response.
Antidepressant medication: when it may form part of treatment
Medication can be helpful in some depressive presentations and should be prescribed and monitored by a medical professional. The decision depends on factors such as severity, history, preferences, previous response, other health conditions, possible adverse effects and the psychological treatments available.
Psychological therapy and medication do not need to be presented as opposing camps. Some people prefer psychological treatment, others benefit from medication, and some require a combination. The decision should be informed, shared and reviewed as treatment progresses.
What if the first treatment does not work?
Not improving with a first treatment does not mean that someone is “untreatable”. It means the case needs to be reviewed.
It may be necessary to revisit whether the original diagnosis adequately explains the presentation; consider bipolar disorder, anxiety, trauma, substance use, pain or physical illness; check whether treatment was delivered for long enough and at sufficient intensity; assess adverse effects and practical barriers; and look again at whether powerful life circumstances are continuing to exert pressure.
NICE recommends reviewing diagnosis and alternative or coexisting conditions when depression has not responded adequately, and considering further treatment options through shared decision-making. A limited response is a clinical signal to reassess the plan, not evidence of personal failure.
Recovery does not usually mean suddenly feeling well again
Recovery is often uneven. Someone may start getting up earlier before pleasure returns. They may return to work and still feel emotionally flat. Sleep may improve while harsh self-criticism remains.
Progress therefore should not be measured only by asking “Are you happy now?”. Greater autonomy, more meaningful activity, better sleep, improved social contact, less avoidance, more ability to make decisions and reduced risk can all be signs that recovery is moving forward.
Relapse prevention can also form part of treatment. Recognising early warning signs, maintaining protective routines, understanding personal patterns of thinking and avoidance and knowing when to seek help can shorten the time between deterioration beginning and support being put in place.
How to support someone with depression without becoming their therapist
Supporting someone does not mean finding the perfect sentence. Reliable presence and practical help are often more useful than trying to persuade someone to “cheer up”.
- listen without immediately turning the conversation into a list of solutions;
- avoid comparing their suffering with other people’s;
- offer concrete help: accompany them to an appointment, prepare food, take a short walk or help with a practical task;
- if they talk about suicide, ask directly and seek professional help when needed;
- do not assume that working or smiling means they are fine;
- keep your own boundaries: supporting someone does not mean carrying full responsibility for their recovery.
If you are supporting an adult son or daughter, our guide on how to support an adult child with depression looks at how to help without invading their autonomy or exhausting yourself.
When should you seek professional help?
You do not have to wait until you have “hit rock bottom”. It is sensible to seek assessment when distress persists, spreads across different areas of life, significantly reduces functioning or includes symptoms that are concerning.
Particular attention is warranted when there is:
- persistent loss of interest or pleasure;
- intense hopelessness;
- progressive isolation;
- significant deterioration in self-care;
- serious difficulty working, studying or meeting basic responsibilities;
- increasing alcohol or substance use to cope with distress;
- psychotic symptoms;
- thoughts of death, self-harm or suicide.
If there is immediate suicide risk or someone cannot keep themselves safe, use urgent services.
Spain: 112 or national suicide support line 024.
Gibraltar: GHA Mental Health Crisis Service 111; emergencies 999.
Frequently asked questions about depression
How do I know whether I am depressed or simply sad?
Sadness can be intense without being depression. Depression usually involves a broader and more persistent pattern affecting mood or pleasure, energy, sleep, thinking, functioning and relationships. Clinical assessment can help when the distinction is unclear.
Do I need five symptoms for two weeks before I can ask for help?
No. Diagnostic criteria may use minimum symptom and duration thresholds when defining an episode, but you can seek help earlier if functioning has deteriorated, risk is present or you simply need to understand what is happening.
Is depression caused by low serotonin?
Depression is not adequately explained by one chemical or one simple biological deficit. It is multifactorial and can involve biological vulnerability, experience, thinking, behaviour, relationships, physical health and social conditions.
Can I have depression and still go to work?
Yes. Some people maintain a large part of their visible functioning at enormous internal cost. Being able to work does not rule depression out; the whole clinical picture matters.
Does depression always involve sadness?
Not necessarily as the main experience. Loss of interest or pleasure, emptiness, irritability, exhaustion, slowing down or emotional numbness may be more prominent.
Is behavioural activation just forcing yourself to do things?
No. Good behavioural activation begins with functional assessment and individualised goals. It uses realistic steps to reduce avoidance and reconnect the person with activities, relationships or responsibilities that matter to them.
Is cognitive therapy just positive thinking?
No. It aims to understand the meaning of thoughts, test interpretations and develop more accurate and flexible ways of thinking. It does not deny real problems or replace them with optimistic statements.
Do I need antidepressants if I have depression?
Not everyone with depression needs medication. Whether it is appropriate depends on severity, clinical history, preferences, previous treatment and other factors. If used, it should be prescribed and monitored by a medical professional.
Can depression come back after recovery?
Yes, some people experience recurrent episodes and others do not. Treatment may therefore include relapse prevention, early-warning signs and a plan for what to do if symptoms return.
Can people recover from depression?
Many people recover from depressive episodes. The course varies: some episodes are isolated, some recur and some presentations require longer-term treatment. Having experienced depression does not mean you are destined to feel this way permanently.
The idea I would like you to take away
One thing I try to communicate when working with someone who is depressed is that depression is not a definition of who they are. “I am stuck” is not the same as “I am incapable”. “I have stopped doing many things” is not the same as “I am lazy”. “I cannot imagine a better future right now” does not mean that future cannot exist.
Depression can alter the way a person feels, interprets, anticipates and acts. Treatment aims to bring flexibility back into that system: movement where there has been withdrawal, perspective where thinking has narrowed, connection where isolation has grown and options where everything had started to feel reduced to one possible outcome.
Sources consulted
- Beck, A. T., Rush, A. J., Shaw, B. F., Emery, G., DeRubeis, R. J. & Hollon, S. D. (2024). Cognitive Therapy of Depression, 2nd ed. Guilford Press.
- Martell, C. R., Dimidjian, S. & Herman-Dunn, R. (2022). Behavioral Activation for Depression: A Clinician's Guide, 2nd ed. Guilford Press.
- Gotlib, I. H. & Hammen, C. L. (eds.) (2014). Handbook of Depression, 3rd ed. Guilford Press.
- World Health Organization (2026). Depressive disorder (depression) . Updated 11 September 2026.
- National Institute for Health and Care Excellence (NICE). Depression in adults: treatment and management (NG222) . Published 2022; last reviewed 30 January 2026.
- Spanish Ministry of Health. 024 national suicide support line .
- Gibraltar Health Authority. Mental Health Services and Crisis Team .
Clinical note: this article is for information and does not replace an individual assessment. Depression is heterogeneous and similar symptoms can occur in other psychological, medical or substance-related conditions. If there is immediate suicide risk, psychotic symptoms, severe self-neglect or an inability to remain safe, use urgent health services.
