Diagnosis means finding out step by step whether an illness is present, what form and severity it has, and what influences it. Applied to the diagnosis of depression, this means that specialists diagnose a depressive episode when the diagnostic criteria for depression are met, other illnesses have been ruled out as the cause, and the symptoms noticeably restrict daily life. Many people use the term "determination" instead of diagnosis—both refer to the same process: collecting, checking, and classifying information, and discussing the results transparently.

According to ICD-11, a depressive episode is diagnosed when several typical symptoms prevail for at least two weeks and the ability to function in daily life, work, or relationships is impaired. It is crucial that at least one of the core symptoms is present and, together with additional symptoms, meets the criteria.

Low mood: People with depression feel sad, empty, or emotionally numb for most of the day. This mood persists almost daily and can hardly be brightened by positive events.

Loss of interest and pleasure: Activities that used to be fun or meaningful—such as hobbies, meeting friends, or work tasks—seem unappealing or exhausting. Those affected withdraw and experience less joy in things that were otherwise important to them.

Lack of drive and rapid fatigue: Those affected feel exhausted even after minor activities and find it difficult to get going.

Concentration and decision-making problems: People quickly lose their train of thought, their minds wander, and even simple tasks take unusually long. Making decisions feels arduous because information is harder to organize and evaluate.

Sleep disturbances: Sleep is frequently shortened, interrupted, or, conversely, excessively long without providing real recovery. Many people report waking up early or having restless nights, yet still feeling exhausted in the morning.

Appetite and weight changes: Appetite can significantly decrease or increase, which impacts body weight within a few weeks. These changes occur without a conscious diet or an explainable external cause and are often accompanied by discomfort.

Feelings of worthlessness or excessive guilt: One's own actions are evaluated overcritically, small mistakes seem huge and trigger intense shame. The inner voice is harsh, offers no comfort, and leaves little room for a realistic, kind self-assessment.

Hopelessness: The future looks bleak and unchangeable, as if nothing will ever turn around for the better. Goals lose their meaning, and there is a lack of confidence that one's own steps could make a difference.

Psychomotor retardation or agitation: Movements and speech are noticeably slowed down, as if everything requires more strength, or there is an inner drivenness accompanied by restlessness and an inability to sit still. Outsiders often perceive these changes clearly.

Suicidal thoughts: Some of those affected think about death or develop concrete plans for suicide; this is a serious warning sign. In this case, immediate help is vital—it is best to speak with trusted individuals right away and contact professional emergency services.

If you suspect that depression might be present, make an appointment with a doctor. During the consultation, a clear picture emerges, forming the basis on which further decisions are made.

• You have a family doctor: Call the practice or use the online appointment booking system on the practice website or patient portal, if available. Briefly state that it is about "persistent low mood or suspected depression." If possible, request a prompt appointment and mention sleep disturbances, loss of joy, or suicidal thoughts if present—this helps the practice assess the urgency.
• You do not have a family doctor (yet): Use the doctor search tool provided by your health insurance company or the Association of Public Health Insurance Physicians (Kassenärztliche Vereinigung - KV), or ask friends and family for recommendations. Company medical officers or university outpatient clinics (for students) are also viable entry points. Many practices offer online calendars. Otherwise, call briefly and state the reason for your visit.
• You prefer a psychotherapeutic point of contact: Psychotherapeutic practices offer initial consultations. They can assess your mental health situation, document an ICD diagnosis, and explain the subsequent medical clearance process (laboratory tests/organic checks). Ask for an initial consultation appointment and explain your main symptoms.
• If it is urgent: In case of severe worsening, restlessness, helplessness, or suicidal thoughts: call 112 or go to the emergency room of the nearest hospital. You can also contact the TelefonSeelsorge (Crisis Helpline) 24/7 (0800-1110111 or 0800-1110222)—they will help you take the next safe step.

The situation at the doctor’s office is essentially a conversation. From the doctor's perspective, this patient consultation typically involves the following steps:

• Clarifying the reason for the visit and core symptoms: During the conversation, you describe what brought you to the practice, how long the symptoms have persisted, and which core symptoms are most prominent. The goal is to create a shared understanding of the situation. Some practices use the PHQ-9 before or during the consultation. This helps them systematically record symptoms and compare progress later on.
• Anamnesis: Life situation and progression: The doctor asks about previous illnesses, family history, sleep, substance use (e.g., alcohol, cannabis), stressors, and past episodes. This creates a comprehensive overview that supports the assessment. Additionally, they document where the depression causes limitations—whether at work or education, at home, or in relationships. This helps later with treatment planning.
• Basic physical examination: An examination follows to rule out physical causes for the symptoms. Blood may also be drawn and sent to a laboratory to determine vital signs.
• Exclusion of other mental health conditions: Specialists check whether the symptoms can be better explained by other disorders—such as anxiety disorders, bipolar disorder, or the effects of substance use (alcohol, drugs).
• Classification according to ICD-11 and severity: The doctor assigns the symptoms to the ICD-11 criteria and assesses the severity level: mild, moderate, or severe. During the consultation, the doctor is also required to ask about acute suicidal risk and high levels of distress.
• Feedback and shared decision-making: The results are explained in an understandable way: Is it depression? What is the severity level? What options are available? Then, a plan is developed together—frequently involving psychotherapy, and if necessary, medication.

If you have to wait a long time for a therapy slot, a Digital Health Application (DiGAs) can help as a bridge and, later, as a supplement. DiGAs are government-certified, CE-marked medical devices "on prescription" that can be prescribed by doctors or psychotherapists. Public health insurance funds cover the costs, provided the application is listed in the BfArM DiGA directory. For depression, deprexis is available—a digital therapy designed for supportive accompaniment during depression.

The dual perspective is vital: diagnosing depression means understanding both the body and the mind. Doctors recognize physical causes or co-existing conditions. Therapists deepen the psychological diagnosis, capturing thought patterns, behavior, and emotions, and create a treatment plan. Together, this creates a cohesive treatment path that supports you both medically and psychotherapeutically.

But who exactly is qualified?

• Family doctors, specialists in psychiatry or psychotherapy: Doctors are permitted to make medical diagnoses and rule out physical causes. They check laboratory values, evaluate medications (e.g., side effects), and can prescribe antidepressants if appropriate. Their role is particularly important during initial illnesses, unusual signs, or physical warning signals.
• Psychological psychotherapists: Psychological psychotherapists are university-educated psychologists who have completed advanced therapeutic training and hold a state license. They are trained in diagnostics and psychotherapy and are legally authorized to diagnose mental disorders, document the ICD findings, and conduct psychotherapy. They do not prescribe medication—instead, they work together with doctors for this purpose.
• Alternative practitioners for psychotherapy: Therapists with an alternative practitioner training and permit are allowed to provide psychotherapy, but they cannot bill public health insurance, issue sick leave certificates or prescriptions, or perform physical diagnostics. If depression is suspected, they should encourage medical clearance and, if necessary, refer the patient to licensed specialists.
• Coaches: Coaches provide support regarding goals, performance, and personal development. While this is valuable, it does not replace diagnosis and treatment. Coaching is not a form of healthcare; therefore, coaches are not allowed to diagnose or treat depression.

First of all, no preparation is necessary. However, if you would like to prepare or get into the right mindset, you can do the following:

• Write down symptoms: Note down how long you have experienced low mood, loss of joy, sleep disturbances, changes in appetite, or issues with drive and concentration, and how they affect your daily life.
• Gather examples: Think of concrete situations at work, university, home, or in your relationships where things are becoming difficult.
• Medications & substances: Bring a list of everything you take (including hormones, herbal supplements, alcohol, and cannabis).
• Past experiences & family history: Note down any previous episodes, treatments, or occurrences of depression within your family.
• Goals and support: Consider what would help you in the short term (e.g., establishing a sleep routine, finding relief from responsibilities, or getting everyday support).

Der PHQ-9 (Patient Health Questionnaire-9) ist ein kurzer Fragebogen mit neun Fragen zu Symptomen der letzten zwei Wochen. Jede Frage wird von 0 (nie) bis 3 (fast jeden Tag) bewertet. Die Summe (0–27) schätzt die Schwere ein: 5–9 leicht, 10–14 mittel, 15–19 moderat-schwer, 20–27 schwer. Ein hoher Wert ersetzt keine Diagnose, ist aber ein klarer Hinweis, professionelle Hilfe zu suchen. Hier findest du den PHQ-9 (deutsch) als PDF.