Depression affects many people and raises important questions about diagnosis and treatment. Therapists play a key role in identifying symptoms and shaping treatment plans through clinical interviews. For an official diagnosis, especially if medication is considered, collaboration with psychiatrists or primary care physicians is common.
In this article, you’ll learn who can diagnose depression, how therapists evaluate symptoms, the criteria used, and what to expect in care. You’ll also see the treatment options available and when seeking professional help makes sense. All of this is grounded in our work at SF Therapy Group in San Francisco.
Who Can Officially Diagnose Depression? Roles of Mental Health Professionals
Depression diagnosis involves a range of mental health professionals, each bringing unique expertise to the process. Understanding their roles helps you know what to expect from assessment through treatment planning.
Licensed depression therapists in San Francisco can provide a clinical diagnosis of depression for therapy purposes. They use clinical interviews, symptom checklists, and standardized tools to determine whether you meet criteria for depressive conditions. Their findings guide psychotherapy and treatment planning, while prescribing medication requires collaboration with psychiatrists or medical providers.
Psychologists conduct therapy and also administer psychological testing to evaluate symptom severity. Their assessments help clarify complex presentations and shape individualized treatment strategies.
Psychiatrists, as medical doctors, conduct medical evaluations, diagnose mental health conditions, and prescribe medication. They play a central role when pharmacological treatment is needed, often working alongside therapists and psychologists.
Primary care physicians are often the first professionals to notice signs of depression. They perform initial screenings, order lab tests to rule out medical issues such as thyroid dysfunction, and refer patients to mental health specialists for comprehensive care.
Together, these professionals create a collaborative system of support, ensuring clients receive both accurate diagnosis and coordinated treatment.
Types of professionals involved in diagnosing depression:
- Therapists (LCSW, LMFT, LPCC): Provide psychotherapy and psychosocial assessments.
- Psychologists (PhD, PsyD): Offer therapy and psychological testing.
- Psychiatrists (MD, DO): Diagnose conditions and prescribe medications.
- Primary Care Physicians (PCP): Screen, order labs, and refer for specialized care.
This integrated approach ensures depression is assessed with care, accuracy, and collaboration.
How Do Therapists Assess Depression Symptoms? The Therapist’s Role in Diagnosis and Treatment Planning
When therapists assess depression, the process is both structured and collaborative. The goal is to understand emotional, cognitive, and behavioral changes in depth. Assessment is not about labeling someone but about creating a clear picture that guides an effective, personalized plan for care.
Clinical Interviews
The assessment usually begins with a detailed clinical interview. Therapists ask about your history, daily experiences, and current challenges. This includes questions about sleep, energy, appetite, motivation, and mood shifts over time. They also explore how depression symptoms affect your work, relationships, and sense of self.
These interviews are conversational rather than rigid. They allow therapists to listen for patterns that reveal both distress and resilience. For example, some clients may describe fatigue and withdrawal, while others describe irritability and difficulty concentrating. Collecting these details provides essential context that questionnaires alone cannot capture.
Standardized Questionnaires
In addition to interviews, therapists often use validated tools that help quantify symptoms. These assessments provide measurable data, making it easier to evaluate severity and track changes across therapy.
- Beck Depression Inventory (BDI-II): Evaluates emotional, cognitive, and physical symptoms, such as sadness, hopelessness, or fatigue.
- Patient Health Questionnaire (PHQ-9): Offers a quick screening tool that measures frequency of depressive symptoms and monitors progress over time.
- Hamilton Rating Scale for Depression (HAM-D): A clinician-administered measure that is especially useful for more complex or severe presentations.
By combining questionnaire results with interview insights, therapists develop a more reliable picture of how depression is expressed and experienced. The data also allows therapists and clients to revisit scores together, making progress more visible.
Symptom Pattern Recognition
Once interviews and questionnaires are complete, therapists analyze the information for consistent symptom patterns. These patterns are compared with established diagnostic criteria, such as DSM-5 and ICD-10 standards, to clarify whether depression is present and how severe it may be.
Pattern recognition is not limited to identifying symptoms.
Therapists also look for triggers, recurring thought cycles, and coping strategies the client has already developed. This helps distinguish between temporary stress responses and a depressive episode that requires deeper intervention. Recognizing these nuances ensures the treatment plan is both accurate and personalized.
Personalized Treatment Planning
After assessment, the therapist’s role is to create a treatment plan that matches the client’s needs, history, and goals. This plan may include different evidence-based approaches, each chosen based on the client’s unique presentation.
One option is Control Mastery Theory (CMT), which is particularly powerful for treating depression. CMT is built on the idea that people are naturally motivated to solve problems and move toward healthier ways of living. Depression often involves unconscious beliefs, such as “I am a burden” or “I do not deserve happiness,” that keep someone feeling stuck.
With CMT, therapy becomes a safe place to test these beliefs in real time. The therapist helps clients notice where old fears or assumptions may be influencing their thoughts and behaviors. For example, a client may begin to see that sharing sadness does not push others away but instead strengthens connection.
This approach allows people to gradually revise beliefs that fuel depression, replacing them with healthier, more accurate ways of understanding themselves and their relationships. Over time, clients often experience more relief, greater self-confidence, and improved mood stability.
When Should You Seek Professional Help for Depression? Recognizing Symptoms and Warning Signs
Identifying the right moment to seek professional help is crucial. Depression develops gradually, and early intervention can prevent worsening symptoms. Recognizing these signs provides clarity and encourages individuals in San Francisco to reach out before symptoms escalate.
Persistent Sadness or Irritability
A depressed mood that lasts most of the day, nearly every day, is a central sign of clinical depression. This mood can feel like an unshakable heaviness or emotional numbness that disrupts daily life. In some cases, irritability replaces sadness, showing up as frustration or low tolerance for stress. When these feelings persist, professional assessment helps distinguish situational sadness from a depressive disorder.
Loss of Interest or Pleasure
Diminished interest in activities once enjoyed is another defining symptom. Hobbies, socializing, or even daily routines may lose their sense of meaning. This loss of pleasure, called anhedonia, often reduces motivation and increases withdrawal from meaningful experiences. Over time, it may cause people to feel disconnected from relationships or accomplishments that once brought satisfaction.
Appetite and Weight Changes
Depression frequently disrupts appetite and eating habits. Some individuals lose interest in food, leading to weight loss or nutritional concerns. Others may experience increased cravings and overeating, often resulting in weight gain. These changes occur without intentional dieting or lifestyle adjustments, reflecting the body’s physiological response to mood disturbances. Such shifts can further impact energy levels and overall health.
Sleep Disturbances
Insomnia and oversleeping are common with depression. Some people struggle to fall or stay asleep, while others wake earlier than intended. Conversely, hypersomnia may lead to sleeping excessively without feeling rested. Sleep disruption worsens fatigue, concentration difficulties, and mood instability, creating a cycle that intensifies depressive symptoms. Persistent sleep changes are a strong indicator that evaluation is needed.
Fatigue and Loss of Energy
Depression often produces exhaustion that does not improve with rest. Many describe feeling drained, even after sufficient sleep. Routine responsibilities, such as preparing meals or commuting, may feel overwhelming. This loss of energy reflects both psychological strain and physical effects of depression, further reinforcing difficulties in work, school, or relationships.
Difficulty Concentrating
Concentration and decision-making frequently decline with depression. Tasks that once felt manageable may now require significant effort or remain incomplete. Individuals often describe their minds as “foggy,” with memory lapses and reduced problem-solving ability. These cognitive symptoms directly affect productivity, professional performance, and overall confidence, contributing to a sense of discouragement and inadequacy.
Unexplained Physical Aches
Depression is not only emotional—it can also manifest physically. Headaches, muscle pain, or gastrointestinal issues may appear without a medical cause. These somatic symptoms often lead people to seek medical treatment before realizing the underlying depression. When physical discomfort persists alongside mood changes, therapy offers a pathway to relief that addresses both mind and body.
Duration of Symptoms
Clinical depression is identified by the persistence of symptoms for at least two weeks. This timeframe is critical for accurate diagnosis. While temporary sadness or stress may resolve, sustained low mood or loss of interest signals the need for evaluation. Recognizing this duration helps therapists in San Francisco distinguish depression from short-term emotional responses.
What Are the Diagnostic Criteria for Depression? Understanding DSM-5 and ICD-10 Standards
Accurate diagnosis of depression depends on established clinical frameworks. Two of the most widely used are the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), published by the American Psychiatric Association, and the International Classification of Diseases, Tenth Revision (ICD-10), developed by the World Health Organization.
These standards provide clear definitions, symptom thresholds, and severity levels that guide therapists and physicians worldwide. For clients in California, familiarity with these systems helps explain how mental health professionals determine whether depression is present and how severe it may be.
DSM-5 Criteria for Major Depressive Disorder
According to the DSM-5 (American Psychiatric Association, 2013), Major Depressive Disorder (MDD) is diagnosed when at least five symptoms occur during the same two-week period. One of the symptoms must be either a persistently depressed mood or a loss of interest or pleasure. This ensures that the diagnosis captures both emotional and behavioral aspects of depression.
The full list of DSM-5 symptoms includes:
- Depressed mood most of the day, nearly every day
- Diminished interest or pleasure in almost all activities
- Significant weight loss, weight gain, or appetite change
- Insomnia or hypersomnia
- Observable psychomotor agitation or slowing
- Fatigue or loss of energy
- Feelings of worthlessness or excessive, inappropriate guilt
- Difficulty concentrating, thinking, or making decisions
- Recurrent thoughts of death, suicidal ideation, or attempts
For a diagnosis, these symptoms must cause clinically significant distress or impairment in social, occupational, or daily functioning. The DSM-5 emphasizes that symptoms cannot be better explained by medical conditions, substances, or normal grief.
This distinction helps therapists and psychiatrists in San Francisco determine when a client’s symptoms meet criteria for Major Depressive Disorder, guiding both diagnosis and treatment planning.
ICD-10 Classification of Depressive Episodes
The ICD-10 (World Health Organization, 1992) provides a parallel but slightly different framework. Depression is classified under F32.x codes for single depressive episodes and F33.x codes for recurrent depressive disorder. Unlike the DSM-5, which lists symptoms, ICD-10 emphasizes symptom clusters and assigns categories based on severity.
ICD-10 Codes for Depressive Episodes:
| ICD-10 Code | Episode Specification | Key Characteristics |
|---|---|---|
| F32.0 | Mild Depressive Episode | At least two core symptoms plus 1–2 additional symptoms |
| F32.1 | Moderate Depressive Episode | At least two core symptoms plus 3–4 additional symptoms |
| F32.2 | Severe Depressive Episode | Three core symptoms plus 4+ additional symptoms, no psychotic features |
| F32.3 | Severe with Psychotic Symptoms | Severe symptoms with delusions, hallucinations, or psychotic features |
According to the WHO, the three core symptoms are: depressed mood, loss of interest and enjoyment, and reduced energy. Severity is then determined by how many additional symptoms are present and the degree of impairment. This coding system not only guides treatment but also supports international research, public health tracking, and structured clinical documentation.
How Is Depression Severity Determined? Mild, Moderate, and Severe Categories
When diagnosing depression, therapists assess both the number of symptoms and the level of disruption in daily life. Severity levels help determine treatment focus, session frequency, and when medical collaboration may be required.
Mild Depression
Mild depression involves at least two core symptoms, such as low mood or loss of interest, plus one or two additional symptoms. These symptoms may feel uncomfortable but generally allow individuals to maintain basic daily responsibilities.
Functional impairment is limited, though motivation, focus, and enjoyment may noticeably decline. Clients in San Francisco often present with mild depression when stressors or life transitions trigger persistent sadness or reduced engagement.
Moderate Depression
Moderate depression is identified when at least two core symptoms occur along with three or four additional symptoms. The impact is more noticeable, often affecting workplace performance, personal relationships, and social functioning.
Daily tasks may feel overwhelming, leading to avoidance or decreased productivity. This level of severity often prompts individuals to seek therapy, as the interference with daily life becomes harder to manage without professional support.
Severe Depression
Severe depression includes three core symptoms and at least four additional symptoms, often with significant impairment across multiple areas of life. Fatigue, hopelessness, and suicidal thoughts may appear, and functioning can be profoundly reduced.
In some cases, severe depression includes psychotic features such as delusions or hallucinations. At this level, therapists in San Francisco often collaborate with psychiatrists or primary care physicians to ensure safety and comprehensive care.
Why Severity Matters?
Determining severity is essential for creating effective treatment plans. Mild cases may focus on building coping skills, while severe cases may require coordinated care with medical providers. Severity also guides the intensity of therapy, ensuring support matches the client’s immediate needs and long-term goals.
What Types of Depression Can Therapists Help Diagnose and Treat?
Depression does not look the same for everyone. Therapists are trained to recognize its many forms, each with distinct patterns, duration, and impact. Understanding these types helps clarify what a diagnosis means and how treatment may be tailored.
Major Depressive Disorder
Major Depressive Disorder (MDD) is defined by the DSM-5 as at least five symptoms present during a two-week period. One must include depressed mood or loss of interest, with additional symptoms such as sleep disruption, fatigue, or feelings of worthlessness. These symptoms cause significant distress or impairment in daily functioning (Li, Ruan, Chen, & Fang, 2021). Therapists in San Francisco carefully assess severity and impact, guiding clients toward psychotherapy that promotes relief and sustainable change.
Persistent Depressive Disorder (Dysthymia)
Persistent Depressive Disorder involves a depressed mood lasting for at least two years in adults, or one year in children (Patel, Aslam, & Rose, 2025). Symptoms are fewer than in major depression but remain consistent, creating a long-term strain on daily functioning. Clients may report low self-esteem, negative thinking, and chronic fatigue. Therapists support individuals by helping them identify unhelpful patterns, strengthen coping strategies, and foster resilience through consistent therapeutic work.
Seasonal Affective Disorder
Seasonal Affective Disorder (SAD) is characterized by recurrent depressive episodes during specific times of the year, most commonly in winter. Symptoms often include low energy, increased sleep, weight changes, and diminished concentration. According to the Seasonal Pattern Assessment Questionnaire, seasonal patterns in depression can be identified and distinguished from other mood disorders. Therapists in San Francisco use these tools to better understand how environmental and biological rhythms affect mood.
Perinatal Depression
Perinatal depression occurs during pregnancy or within the first year following childbirth. It is influenced by hormonal shifts, sleep deprivation, and psychosocial stressors. Symptoms can include intense sadness, irritability, difficulty bonding with the infant, and feelings of guilt or inadequacy. The Edinburgh Postnatal Depression Scale is frequently used to screen for perinatal depression. Therapists provide assessment and support, helping parents manage symptoms while strengthening attachment and emotional health during this critical time.
What to Expect During a Depression Assessment at SF Therapy Group in San Francisco
A depression assessment at SF Therapy Group is a supportive, structured process designed to help you feel understood from the very first session. The focus is on listening carefully, gathering meaningful information, and creating a therapy plan rooted in Control Mastery Theory.
The Evaluation Process
Your first session typically lasts 50 to 90 minutes. During this time, your therapist will:
- Review your personal, medical, and mental health history
- Explore mood patterns, thought processes, and how symptoms affect daily functioning
- Integrate these findings into a clear clinical impression and therapy plan
This approach ensures that both lived experience and measurable data inform the path forward.
Confidentiality and Professional Privacy
Your privacy is central to the process. SF Therapy Group safeguards confidentiality through secure systems, private therapy offices, and compliance with HIPAA standards. Informed consent is reviewed at the start, clarifying how your information is protected. This creates trust, allowing you to share openly and honestly.
Control Mastery Theory as the Foundation
Every therapist at SF Therapy Group is trained in Control Mastery Theory (CMT). This approach views clients as fundamentally healthy and motivated to overcome obstacles. During assessment, therapists look for unconscious beliefs or fears that may reinforce depression. The therapy plan then becomes a space where you can safely test and revise these beliefs, leading to greater freedom and resilience. For example, someone who feels they must not burden others with sadness may discover, through therapy, that openness builds connection rather than distance.
Final Thoughts
Navigating depression can be challenging, but understanding the diagnostic process and available support is the first step toward recovery. Therapists are integral in this journey, providing assessment, treatment planning, and ongoing support. Remember, seeking professional help is a sign of strength, and with the right guidance, healing and well-being are achievable.
Frequently Asked Questions
Can a therapist prescribe medication for depression?
Licensed therapists (LCSW, LMFT, LPCC) in California cannot prescribe medication. This role is reserved for psychiatrists or medical doctors. Therapists often collaborate with these professionals to ensure clients receive comprehensive care, including medication management if deemed necessary.
How long does it take to get a diagnosis for depression?
A formal diagnosis typically involves one or more assessment sessions. Therapists use clinical interviews and standardized tools to gather information. The time frame can vary, but often a preliminary assessment can be completed within the first few sessions, with a confirmed diagnosis following as more information is gathered.
When do therapists refer clients to psychiatrists for formal diagnosis?
Therapists initiate referrals to psychiatrists when clients exhibit severe or treatment-resistant symptoms, require medication management, or present safety concerns such as suicidal ideation. A psychiatrist’s medical expertise ensures accurate medical diagnosis and pharmacological intervention when psychotherapy alone may be insufficient. By maintaining open communication, therapists and psychiatrists collaborate to optimize treatment outcomes and safeguard client well-being.
Is depression a lifelong condition?
Depression can be a chronic condition for some, but it is often treatable and manageable. With appropriate therapy, medication, and lifestyle adjustments, many individuals experience significant symptom reduction and can achieve long periods of remission. Early intervention and consistent support are key.
References
- World Health Organization. (1992). The ICD-10 classification of mental and behavioural disorders: Clinical descriptions and diagnostic guidelines. Geneva: World Health Organization.
- American Psychiatric Association, DSM-5 Task Force. (2013). Diagnostic and statistical manual of mental disorders: DSM-5 (5th ed.). American Psychiatric Publishing.
- Patel, R. K., Aslam, S. P., & Rose, G. M. (2025). Persistent depressive disorder. In StatPearls [Internet]. StatPearls Publishing.
- Li, Z., Ruan, M., Chen, J., & Fang, Y. (2021). Major depressive disorder: Advances in neuroscience research and translational applications. Neuroscience Bulletin, 37(6), 863–880.
