There are several major psychological disorders or conditions that are studied in psychology for Class 12. These disorders are categorized into different groups based on their symptoms and characteristics. Here are some of the major psychological disorders or conditions studied in psychology for Class 12:

1. Mood Disorders:
- Major Depressive Disorder: A mood disorder characterized by persistent feelings of sadness, hopelessness, and a loss of interest in activities.
- Bipolar Disorder: A mood disorder characterized by alternating periods of depression and mania.

2. Anxiety Disorders:
- Generalized Anxiety Disorder: A disorder characterized by excessive and uncontrollable worry and anxiety about everyday events or activities.
- Panic Disorder: A disorder characterized by recurrent panic attacks, which are sudden and intense episodes of fear accompanied by physical symptoms.
- Social Anxiety Disorder: A disorder characterized by an intense fear of social situations and a fear of being judged or embarrassed by others.

3. Personality Disorders:
- Borderline Personality Disorder: A disorder characterized by unstable relationships, impulsive behavior, and a distorted sense of self.
- Antisocial Personality Disorder: A disorder characterized by a disregard for the rights of others, lack of empathy, and a pattern of manipulative and deceitful behavior.

4. Eating Disorders:
- Anorexia Nervosa: A disorder characterized by an intense fear of gaining weight, a distorted body image, and extreme weight loss.
- Bulimia Nervosa: A disorder characterized by binge-eating followed by compensatory behaviors such as self-induced vomiting or excessive exercise.

5. Schizophrenia:
- Schizophrenia: A disorder characterized by a range of symptoms including hallucinations, delusions, disorganized thinking, and social withdrawal.

6. Obsessive-Compulsive Disorder (OCD):
- OCD: A disorder characterized by intrusive thoughts (obsessions) and repetitive behaviors or mental acts (compulsions) performed to alleviate anxiety.

These are just some of the major psychological disorders or conditions studied in psychology for Class 12. It is important to note that each disorder or condition has its own set of diagnostic criteria and treatment approaches. Understanding these disorders and their impact on individuals' lives is crucial for developing effective interventions and support.